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1

Quantum noise minimization in transistor amplifiers  

E-print Network

General quantum restrictions on the noise performance of linear transistor amplifiers are used to identify the region in parameter space where the quantum-limited performance is achievable and to construct a practical procedure for approaching it experimentally using only the knowledge of directly measurable quantities: the gain, (differential) conductance and the output noise. A specific example of resonant barrier transistors is discussed.

U. Gavish; B. Yurke; Y. Imry

2006-04-10

2

Transistor circuit increases range of logarithmic current amplifier  

NASA Technical Reports Server (NTRS)

Circuit increases the range of a logarithmic current amplifier by combining a commercially available amplifier with a silicon epitaxial transistor. A temperature compensating network is provided for the transistor.

Gilmour, G.

1966-01-01

3

Simple way of teaching transistor amplifiers Bogdan M. Wilamowski  

E-print Network

Simple way of teaching transistor amplifiers Bogdan M. Wilamowski University of Wyoming Abstract for transistor amplifiers [1][2][3][4]. They do relatively well if a common source (emitter) is used, but they are lost when other configurations are considered. In the paper, a simple way for analysis of transistor

Wilamowski, Bogdan Maciej

4

Characterization of a Common-Source Amplifier Using Ferroelectric Transistors  

NASA Technical Reports Server (NTRS)

This paper presents empirical data that was collected through experiments using a FeFET in the established common-source amplifier circuit. The unique behavior of the FeFET lends itself to interesting and useful operation in this widely used common-source amplifier. The paper examines the effect of using a ferroelectric transistor for the amplifier. It also examines the effects of varying load resistance, biasing, and input voltages on the output signal and gives several examples of the output of the amplifier for a given input. The difference between a commonsource amplifier using a ferroelectric transistor and that using a MOSFET is addressed.

Hunt, Mitchell; Sayyah, Rana; MacLeond, Todd C.; Ho, Pat D.

2010-01-01

5

InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz  

NASA Technical Reports Server (NTRS)

Two single-stage InP heterojunction bipolar transistor (HBT) amplifiers operate at 184 and 255 GHz, using Northrop Grumman Corporation s InP HBT MMIC (monolithic microwave integrated circuit) technology. At the time of this reporting, these are reported to be the highest HBT amplifiers ever created. The purpose of the amplifier design is to evaluate the technology capability for high-frequency designs and verify the model for future development work.

Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, William; Dang, Linh; Li, Danny; Cavus, Abdullah; To, Richard; Lai, Richard

2009-01-01

6

Characterization of a Common-Gate Amplifier Using Ferroelectric Transistors  

NASA Technical Reports Server (NTRS)

In this paper, the empirical data collected through experiments performed using a FeFET in the common-gate amplifier circuit is presented. The FeFET common-gate amplifier was characterized by varying all parameters in the circuit, such as load resistance, biasing of the transistor, and input voltages. Due to the polarization of the ferroelectric layer, the particular behavior of the FeFET common-gate amplifier presents interesting results. Furthermore, the differences between a FeFET common-gate amplifier and a MOSFET common-gate amplifier are examined.

Hunt, Mitchell; Sayyah, Rana; MacLeod, Todd C.; Ho, Fat D.

2011-01-01

7

Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis  

NASA Technical Reports Server (NTRS)

There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

2008-01-01

8

Thermoelectric energy scavenging from waste heat of power amplifier transistors  

Microsoft Academic Search

A thermoelectric (TE) energy scavenging technique is proposed to recover energy from the waste heat of power amplifier (PA) transistors. Explored are optimized pellet geometries for maximum efficiency and performance of TE power generation scavenging energy under various parametric conditions. A fully-coupled TE model is developed and integrates TE physics with heat transfer physics. The TE model is exercised to

Kyoung Joon Kim; Marc Hodes

2009-01-01

9

Simple Introduction to Transistor (BJT) Amplifier  

E-print Network

"inject" the signal we want to amplify 1 mA 3. Ohms law sets emitter current 1.0v / 1000 = 1mA VC = 10V 4. Ohms law says 10V across RC, putting the collector at VC = 10 V 1mA Ã? 10k = 10v 1.7V 1. Voltage... we can also use a water model BJT Water Model Fig. 28.5 from Electrical Engineering Uncovered Base

Fowler, Mark

10

Triple-Mode Single-Transistor Graphene Amplifier and Its Applications  

E-print Network

Triple-Mode Single-Transistor Graphene Amplifier and Its Applications Xuebei Yang,, Guanxiong Liu University, Houston, Texas 77005, United States. These authors contributed equally to this work. T he single-transistor amplifier, which consists of one transistor and one re- sistor, is one of the most basic and most important

11

18.1 Introduction The traditional approach to the small-signal analysis of transistor amplifiers employs the transistor  

E-print Network

18-1 18.1 Introduction The traditional approach to the small-signal analysis of transistor amplifiers employs the transistor models with dependent sources, illustrated in Figure 18.1, for both the MOS and BJT devices. In this chapter, techniques for the analysis of transistor circuits will be demonstrated

Wilamowski, Bogdan Maciej

12

Imperial College London EEE 1L4 Autumn 2009 E2.2 Analogue Electronics More transistor amplifiers  

E-print Network

Imperial College London ­ EEE 1L4 Autumn 2009 E2.2 Analogue Electronics More transistor amplifiers Base ­ Common Collector · Study the single transistor MOSFET amplifiers #12;Imperial College London London ­ EEE 3L4 Autumn 2009 E2.2 Analogue Electronics The 2nd form of the Miller theorem · consider

Papavassiliou, Christos

13

Modeling a Common-Source Amplifier Using a Ferroelectric Transistor  

NASA Technical Reports Server (NTRS)

This paper presents a mathematical model characterizing the behavior of a common-source amplifier using a FeFET. The model is based on empirical data and incorporates several variables that affect the output, including frequency, load resistance, and gate-to-source voltage. Since the common-source amplifier is the most widely used amplifier in MOS technology, understanding and modeling the behavior of the FeFET-based common-source amplifier will help in the integration of FeFETs into many circuits.

Sayyah, Rana; Hunt, Mitchell; MacLeond, Todd C.; Ho, Fat D.

2010-01-01

14

Transistor power losses in the class E tuned power amplifier  

Microsoft Academic Search

The class E switching-mode tuned power amplifier offers efficiency approaching 100 percent. It is especially applicable at high frequencies because it minimizes the power dissipated during the switching transitions, even if the switching time is an appreciable fraction of the signal period. When the amplifier is properly loaded and tuned, power losses are caused primarily by active-device saturation voltage and

FREDERICK H. RAAB; NATHAN O. SOKAL

1978-01-01

15

THz Electronics projects at DARPA: Transistors, TMICs, and amplifiers  

Microsoft Academic Search

Revolutionary THz transmitter and receiver demonstrations are the ongoing focus of a portfolio of programs within the DARPA. Through the sponsorship of the Terahertz Electronics and related programs, a technology base is being established to effectively generate, detect, process, and radiate sub-MMW frequencies to exploit this practically inaccessible frequency domain for imaging, radar, spectroscopy, and communications applications. Transistors, integration technologies,

J. D. Albrecht; M. J. Rosker; H. B. Wallace; T. Chang

2010-01-01

16

THz electronics projects at DARPA: Transistors, TMICs, and amplifiers  

Microsoft Academic Search

Revolutionary THz transmitter and receiver demonstrations are the ongoing focus of a portfolio of programs within the DARPA. Through the sponsorship of the Terahertz Electronics and related programs, a technology base is being established to effectively generate, detect, process, and radiate sub-MMW frequencies to exploit this practically inaccessible frequency domain for imaging, radar, spectroscopy, and communications applications. Transistors, integration technologies,

John D. Albrecht; Mark J. Rosker; H. Bruce Wallace; Tsu-Hsi Chang

2010-01-01

17

Field Effect Transistor /FET/ circuit for variable gin amplifiers  

NASA Technical Reports Server (NTRS)

Amplifier circuit using two FETs combines improved input and output impedances with relatively large signal handling capability and an immunity from adverse effects of automatic gain control. Circuit has sources and drains in parallel plus a resistive divider for signal and bias to either of the gate terminals.

Spaid, G. H.

1969-01-01

18

Note: cryogenic low-noise dc-coupled wideband differential amplifier based on SiGe heterojunction bipolar transistors.  

PubMed

Silicon-germanium heterojunction bipolar transistors can be used to construct low-noise cryogenic amplifiers. We present a dc-coupled differential amplifier capable of operating down to 10 K. In this temperature regime it has bandwidth of 15 MHz and noise temperature as low as 1.3 K. When operated at liquid nitrogen temperature of 77 K, the measured noise temperature is lower than 3 K. The amplifier is based on the commercially available transistors NESG3031 and operational amplifier OPA836 and is capable of standalone operation without any additional stages at room temperature. PMID:22755673

Beev, Nikolai; Kiviranta, Mikko

2012-06-01

19

Realization of a Charge Transformer; A Noise Matching Device for Single Electron Transistor Amplifiers.  

NASA Astrophysics Data System (ADS)

We present a new device, called a charge transformer, which can be used to enhance noise performance of single electron transistor (SET) amplifiers when placed between a low capacitance SET and a high capacitance device under test. The function of a charge transformer is analogous to that of a flux transformer commonly used with superconducting quantum interference devices (SQUIDs). A prototype charge transformer consisting of 4 identical capacitors and 13 switches is fabricated using a GaAs/AlGaAs heterostructure with a two-dimensional electron gas. The switches enable capacitors to be connected either in series or in parallel. During operation the capactiors switch back and forth between the parallel and series configuration with clock frequencies up to 3 MHz. We believe SET amplifiers integrated with a charge transformer on the same chip, may find applications in various fields where low-noise electrometers are needed. Fabrication and noise analysis of the charge transformer will be discussed.

Lewis, Kim; Kurdak, Cagliyan; Krishna, S.; Bhattacharya, P.

2002-03-01

20

A Short Study on the Validity of Miller's Theorem Applied to Transistor Amplifier High-Frequency Performance  

ERIC Educational Resources Information Center

The use of Miller's Theorem in the determination of the high-frequency cutoff frequency of transistor amplifiers was recently challenged by a paper published in this TRANSACTIONS. Unfortunately, that paper provided no simulation or experimental results to bring credence to the challenge or to validate the alternate method of determination…

Schubert, T. F., Jr.; Kim, E. M.

2009-01-01

21

Transistors  

NSDL National Science Digital Library

How does a transistor work ? History of semi-conductors Visit the museum of how the transistor was developed. Transistor history The Transistor Museum How stuff works Visit this site and follow through a short course on how a semi-conductor works. How stuff works PBS site Visit the PBS site of transistors and semi-conductors. Watch shorth videos on the development of the transistor. Timeline pbs ...

Mr. Blackburn

2004-07-05

22

Charge Transformer to Enhance Noise Performance of Single Electron Transistor Amplifiers in High Capacitance Applications.  

NASA Astrophysics Data System (ADS)

We propose a new device, called a charge transformer, which can be used to enhance noise performance of single electron transistor (SET) amplifiers in applications where a large capacitance macroscopic device needs to be measured. The function of a charge transformer is analogous to that of a flux transformer commonly used with superconducting quantum interference devices (SQUIDs). Our charge transformer consists of N identical capacitors and switches that enable capacitors to be connected either in series or in parallel. The capacitors will be switched back and forth between the parallel and series configurations with speeds faster than the signals that will be measured. To achieve optimum noise performance, we choose N and the capacitance such that in series and parallel configurations, the equivalent capacitance will be matched to the gate capacitance of the SET and the capacitance of the device under test, respectively. The fabrication of the charge transformer using GaAs/AlGaAs heterostructures and its practical limitations will be discussed.

Lewis, K. M.; Kurdak, C.

2001-03-01

23

Design of an Auto-zeroed, Differential, Organic Thin-film Field-effect Transistor Amplifier for Sensor Applications  

NASA Technical Reports Server (NTRS)

Organic strain gauge and other sensors require high-gain, precision dc amplification to process their low-level output signals. Ideally, amplifiers would be fabricated using organic thin-film field-effect transistors (OTFT's) adjacent to the sensors. However, OTFT amplifiers exhibit low gain and high input-referred dc offsets that must be effectively managed. This paper presents a four-stage, cascaded differential OTFT amplifier utilizing switched capacitor auto-zeroing. Each stage provides a nominal voltage gain of four through a differential pair driving low-impedance active loads, which provide common-mode output voltage control. p-type pentacence OTFT's are used for the amplifier devices and auto-zero switches. Simulations indicate the amplifier provides a nominal voltage gain of 280 V/V and effectively amplifies a 1-mV dc signal in the presence of 500-mV amplifier input-referred dc offset voltages. Future work could include the addition of digital gain calibration and offset correction of residual offsets associated with charge injection imbalance in the differential circuits.

Binkley, David M.; Verma, Nikhil; Crawford, Robert L.; Brandon, Erik; Jackson, Thomas N.

2004-01-01

24

Demonstration of a 0.48 THz Amplifier Module Using InP HEMT Transistors  

Microsoft Academic Search

In this letter, we present an amplifier module operating at a frequency of 0.48 THz. This represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date. The amplifier demonstrates a peak gain of 11.7 dB measured in a waveguide split-block housing. Sub 50-nm InP HEMT

W. R. Deal; X. B. Mei; V. Radisic; K. Leong; S. Sarkozy; B. Gorospe; J. Lee; P. H. Liu; W. Yoshida; J. Zhou; M. Lange; J. Uyeda; R. Lai

2010-01-01

25

e bipolar junction transistor (BJT) is historically the first solid-state analog amplifier and digital switch, and formed the basis of integrated circuits (IC) in the 1970s. Starting in the early 1980s, the  

E-print Network

9-1 e bipolar junction transistor (BJT) is historically the first solid-state analog amplifier, the invention of silicon­germanium base heterojunction bipolar transistor (SiGe HBT) brought the bipolar are injected from the emitter to base, 9 Bipolar Junction Transistor 9.1 Ebers­Moll Model

Wilamowski, Bogdan Maciej

26

A Mathematical Model of a Simple Amplifier Using a Ferroelectric Transistor  

NASA Technical Reports Server (NTRS)

This paper presents a mathematical model characterizing the behavior of a simple amplifier using a FeFET. The model is based on empirical data and incorporates several variables that affect the output, including frequency, load resistance, and gate-to-source voltage. Since the amplifier is the basis of many circuit configurations, a mathematical model that describes the behavior of a FeFET-based amplifier will help in the integration of FeFETs into many other circuits.

Sayyah, Rana; Hunt, Mitchell; MacLeod, Todd C.; Ho, Fat D.

2009-01-01

27

RF Single Electron Transistor Readout Amplifiers for Superconducting Astronomical Detectors for X-Ray to Sub-mm Wavelengths  

NASA Technical Reports Server (NTRS)

We report progress on using a new type of amplifier, the Radio-Frequency Single-Electron Transistor (RF-SET), to develop multi-channel sensor readout systems for fast and sensitive readout of high impedance cryogenic photodetectors such as Superconducting Tunnel Junctions and Single Quasiparticle Photon Counters. Although cryogenic, these detectors are desirable because of capabilities not other-wise attainable. However, high impedances and low output levels make low-noise, high-speed readouts challenging, and large format arrays would be facilitated by compact, low-power, on-chip integrated amplifiers. Well-suited for this application are RF-SETs, very high performance electrometers which use an rf readout technique to provide 100 MHz bandwidth. Small size, low power, and cryogenic operation allow direct integration with detectors, and using multiple rf carrier frequencies permits simultaneous readout of 20-50 amplifiers with a common electrical connection. We describe both the first 2-channel demonstration of this wavelength division multiplexing technique for RF-SETs, and Charge-Locked-Loop operation with 100 kHz of closed-loop bandwidth.

Stevenson, Thomas; Aassime, Abdelhanin; Delsing, Per; Frunzio, Luigi; Li, Li-Qun; Prober, Daniel; Schoelkopf, Robert; Segall, Ken; Wilson, Chris; Stahle, Carl

2000-01-01

28

Monolithic wideband linear power amplifier with 45% power bandwidth using pseudomorphic high-electron-mobility transistors for long-term evolution application  

NASA Astrophysics Data System (ADS)

A fully integrated, monolithic, wideband linear power amplifier using pseudomorphic high-electron-mobility transistor (pHEMT) technology has been developed for long-term evolution (LTE) applications. Implemented through the stacked field-effect transistor (stacked-FET) configuration, the amplifier exhibited a small signal gain of 15 dB and an output power of 25 dBm at 1 dB compression (P1dB) with a power-added efficiency (PAE) of 36% from 1.7 to 2.7 GHz yielding 45% power bandwidth. Moreover, when tested under a 10 MHz LTE-modulated signal, the amplifier achieved a 3% error-vector-magnitude (EVM) at 23 dBm output power over the entire power bandwidth.

Chiang, Che-Yang; Hsu, Heng-Tung; Chang, Edward Y.

2014-11-01

29

Mathematical Models of the Common-Source and Common-Gate Amplifiers using a Metal-Ferroelectric-Semiconductor Field effect Transistor  

NASA Technical Reports Server (NTRS)

Mathematical models of the common-source and common-gate amplifiers using metal-ferroelectric- semiconductor field effect transistors (MOSFETs) are developed in this paper. The models are compared against data collected with MOSFETs of varying channel lengths and widths, and circuit parameters such as biasing conditions are varied as well. Considerations are made for the capacitance formed by the ferroelectric layer present between the gate and substrate of the transistors. Comparisons between the modeled and measured data are presented in depth as well as differences and advantages as compared to the performance of each circuit using a MOSFET.

Hunt, Mitchell; Sayyah, Rana; Mitchell, Cody; Laws, Crystal; MacLeod, Todd C.; Ho, Fat D.

2013-01-01

30

Extended Characterization of the Common-Source and Common-Gate Amplifiers using a Metal-Ferroelectric-Semiconductor Field Effect Transistor  

NASA Technical Reports Server (NTRS)

Collected data for both common-source and common-gate amplifiers is presented in this paper. Characterizations of the two amplifier circuits using metal-ferroelectric-semiconductor field effect transistors (MFSFETs) are developed with wider input frequency ranges and varying device sizes compared to earlier characterizations. The effects of the ferroelectric layer's capacitance and variation load, quiescent point, or input signal on each circuit are discussed. Comparisons between the MFSFET and MOSFET circuit operation and performance are discussed at length as well as applications and advantages for the MFSFETs.

Hunt, Mitchell; Sayyah, Rana; Mitchell, Cody; Laws, Crystal; MacLeod, Todd C.; Ho, Fat D.

2013-01-01

31

PH-315 A. La Rosa TRANSISTORS and  

E-print Network

PH-315 A. La Rosa TRANSISTORS and TRANSISTOR AMPLIFIERS I. PURPOSE To familiarize with the characteristics of transistors, how to properly implement its DC bias, and illustrate its application as small signal amplifiers. The bipolar junction transistor as well as the field effect transistor

32

A scalable high-frequency noise model for bipolar transistors with application to optimal transistor sizing for low-noise amplifier design  

Microsoft Academic Search

Fully scalable, analytical HF noise parameter equations for bipolar transistors are presented and experimentally tested on high-speed Si and SiGe technologies. A technique for extracting the complete set of transistor noise parameters from Y parameter measurements only is developed and verified. Finally, the noise equations are coupled with scalable variants of the HICUM and SPICE-Gummel-Poon models and are employed in

Sorin P. Voinigescu; Michael C. Maliepaard; Jonathan L. Showell; Greg E. Babcock; David Marchesan; Michael Schroter; Peter Schvan; David L. Harame

1997-01-01

33

Low noise tuned amplifier  

NASA Technical Reports Server (NTRS)

A bandpass amplifier employing a field effect transistor amplifier first stage is described with a resistive load either a.c. or directly coupled to the non-inverting input of an operational amplifier second stage which is loaded in a Wien Bridge configuration. The bandpass amplifier may be operated with a signal injected into the gate terminal of the field effect transistor and the signal output taken from the output terminal of the operational amplifier. The operational amplifier stage appears as an inductive reactance, capacitive reactance and negative resistance at the non-inverting input of the operational amplifier, all of which appear in parallel with the resistive load of the field effect transistor.

Kleinberg, L. L. (inventor)

1984-01-01

34

Amplify Interest in STS.  

ERIC Educational Resources Information Center

Presents activities in which students construct simple crystal radio sets and amplifiers out of diodes, transistors, and integrated circuits. Provides conceptual background, materials needed, instructions, diagrams, and classroom applications. (MDH)

Chiappetta, Eugene L; Mays, John D.

1992-01-01

35

High Power SiGe X-Band (8-10 GHz) Heterojunction Bipolar Transistors and Amplifiers  

NASA Technical Reports Server (NTRS)

Limited by increased parasitics and thermal effects as the device size becomes large, current commercial SiGe power HBTs are difficult to operate at X-band (8-12 GHz) with adequate power added efficiencies at high power levels. We found that, by changing the heterostructure and doping profile of SiGe HBTs, their power gain can be significantly improved without resorting to substantial lateral scaling. Furthermore, employing a common-base configuration with proper doping profile instead of a common-emitter configuration improves the power gain characteristics of SiGe HBTs, which thus permits these devices to be efficiently operated at X-band. In this paper, we report the results of SiGe power HBTs and MMIC power amplifiers operating at 8-10 GHz. At 10 GHz, 22.5 dBm (178 mW) RF output power with concurrent gain of 7.32 dB is measured at the peak power-added efficiency of 20.0% and the maximum RF output power of 24.0 dBm (250 mW) is achieved from a 20 emitter finger SiGe power HBT. Demonstration of single-stage X-band medium-power linear MMIC power amplifier is also realized at 8 GHz. Employing a 10-emitter finger SiGe HBT and on-chip input and output matching passive components, a linear gain of 9.7 dB, a maximum output power of 23.4 dBm and peak power added efficiency of 16% is achieved from the power amplifier. The MMIC exhibits very low distortion with third order intermodulation (IM) suppression C/I of -13 dBc at output power of 21.2 dBm and over 20dBm third order output intercept point (OIP3).

Ma, Zhenqiang; Jiang, Ningyue; Ponchak, George E.; Alterovitz, Samuel A.

2005-01-01

36

Cross-differential amplifier  

NASA Technical Reports Server (NTRS)

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

2013-01-01

37

Cross-differential amplifier  

NASA Technical Reports Server (NTRS)

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

2010-01-01

38

Cross-differential amplifier  

NASA Technical Reports Server (NTRS)

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

2011-01-01

39

Transistor as a Rectifier  

E-print Network

Transistor is a three terminal semiconductor device normally used as an amplifier or as a switch. Here the alternating current (a.c) rectifying property of the transistor is considered. The ordinary silicon diode exhibits a voltage drop of ~0.6V across its terminals. In this article it is shown that the transistor can be used to build a diode or rectify low current a.c (~mA) with a voltage drop of ~0.03V. This voltage is ~20 times smaller than the silicon diode. This article gives the half-wave and full-wave transistor rectifier configurations along with some applications to justify their usefulness.

Baddi, Raju

2012-01-01

40

Transistor as a Rectifier  

E-print Network

Transistor is a three terminal semiconductor device normally used as an amplifier or as a switch. Here the alternating current (a.c) rectifying property of the transistor is considered. The ordinary silicon diode exhibits a voltage drop of ~0.6V across its terminals. In this article it is shown that the transistor can be used to build a diode or rectify low current a.c (~mA) with a voltage drop of ~0.03V. This voltage is ~20 times smaller than the silicon diode. This article gives the half-wave and full-wave transistor rectifier configurations along with some applications to justify their usefulness.

Raju Baddi

2013-04-20

41

High stability amplifier  

NASA Technical Reports Server (NTRS)

An electrical RF signal amplifier for providing high temperature stability and RF isolation and comprised of an integrated circuit voltage regulator, a single transistor, and an integrated circuit operational amplifier mounted on a circuit board such that passive circuit elements are located on side of the circuit board while the active circuit elements are located on the other side is described. The active circuit elements are embedded in a common heat sink so that a common temperature reference is provided for changes in ambient temperature. The single transistor and operational amplifier are connected together to form a feedback amplifier powered from the voltage regulator with transistor implementing primarily the desired signal gain while the operational amplifier implements signal isolation. Further RF isolation is provided by the voltage regulator which inhibits cross-talk from other like amplifiers powered from a common power supply. Input and output terminals consisting of coaxial connectors are located on the sides of a housing in which all the circuit components and heat sink are located.

Adams, W. A.; Reinhardt, V. S. (inventors)

1983-01-01

42

John Bardeen and transistor physics  

NASA Astrophysics Data System (ADS)

John Bardeen and Walter Brattain invented the point-contact semiconductor amplifier (transistor action) in polycrystalline germanium (also observed in polycrystalline silicon) on Dec. 15, 1947, for which they received a patent on Oct. 3, 1950. Bill Shockley was not a co-patent holder on Bardeen and Brattain's point-contact semiconductor amplifier patent since Julius Lilienfeld had already received a patent in 1930 for what would have been Shockley's contribution; namely, the field-effect methodology. Shockley received patents for both his minority-carrier injection concept and junction transistor theory, however, and deservedly shared the Nobel prize with Bardeen and Brattain for his seminal contributions of injection, p-n junction theory and junction transistor theory. We will review the events leading up to the invention of Bardeen and Brattain's point-contact semiconductor amplifier during the magic month of November 17-December 16, 1947 and the invention of Shockley's junction semiconductor amplifier during his magic month of December 24, 1947-January 23, 1948. It was during the course of Bardeen and Brattain's research in November, 1947 that Bardeen also patented the essence of the MOS transistor, wherein the induced minority carriers were confined to the inversion layer enroute to the collector. C. T. Sah has described this device as a sourceless MOS transistor. Indeed, John Bardeen, co-inventor of the point-contact semiconductor amplifier and inventor of the MOS transistor, may rightly be called the father of modern electronics.

Huff, Howard R.

2001-01-01

43

High temperature current mirror amplifier  

DOEpatents

A high temperature current mirror amplifier having biasing means in the transdiode connection of the input transistor for producing a voltage to maintain the base-collector junction reversed-biased and a current means for maintaining a current through the biasing means at high temperatures so that the base-collector junction of the input transistor remained reversed-biased. For accuracy, a second current mirror is provided with a biasing means and current means on the input leg.

Patterson, III, Raymond B. (Melbourne, FL)

1984-05-22

44

John Bardeen and transistor physics  

Microsoft Academic Search

John Bardeen and Walter Brattain invented the point-contact semiconductor amplifier (transistor action) in polycrystalline germanium (also observed in polycrystalline silicon) on Dec. 15, 1947, for which they received a patent on Oct. 3, 1950. Bill Shockley was not a co-patent holder on Bardeen and Brattain’s point-contact semiconductor amplifier patent since Julius Lilienfeld had already received a patent in 1930 for

Howard R. Huff

2001-01-01

45

John Bardeen and transistor physics  

Microsoft Academic Search

John Bardeen and Walter Brattain invented the point-contact semiconductor amplifier (transistor action) in polycrystalline germanium (also observed in polycrystalline silicon) on Dec. 15, 1947, for which they received a patent on Oct. 3, 1950. Bill Shockley was not a co-patent holder on Bardeen and Brattain's point-contact semiconductor amplifier patent since Julius Lilienfeld had already received a patent in 1930 for

Howard R. Huff

2001-01-01

46

Reigniting innovation in the transistor  

Microsoft Academic Search

Today the transistor is integral to the electronic circuitry that wires our lives. When Bardeen and Brattain first observed an amplified signal by connecting electrodes to a germanium crystal they saw that their 'semiconductor triode' could prove a useful alternative to the more cumbersome vacuum tubes used at the time [1]. But it was perhaps William Schottky who recognized the

Anna Demming

2012-01-01

47

technologie transistor.  

E-print Network

�léments de technologie Les circuits intégrées c-MOS. L'élément de base est le transistor. Deux types de transistors complémentaires n-MOS et p-MOS. Avantages des c-MOS : #21; très grande intégration des impuretés. - plus récement : bombardement ionique. 2 #12; Transistor n-MOS (Metal

Hivert, Florent

48

Development of Sub-Millimeter-Wave Power Amplifiers  

NASA Astrophysics Data System (ADS)

In this paper, we present the framework for developing the first working power amplifiers at sub-millimeter-wave frequencies. The technology is made possible by an advanced InP HEMT transistor. A three-stage power amplifier is presented, which uses a binary combiner to realize a total output periphery of 80 mum and demonstrates 12-dB gain at 335 GHz, making, this the first demonstrated sub-millimeter-wave power amplifier. Measured saturated power of 2 mW at 330 GHz is also presented, which provides a transistor power benchmark of 25 mW/mm at 330 GHz. Finally, single-stage amplifier data with large periphery transistors are presented, which demonstrates 5-dB measured gain at 230 GHz and positive measured S21 gain to ~300 GHz, demonstrating that power amplifiers using larger transistors are feasible at these frequencies as well.

Deal, William R.; Mei, X. B.; Radisic, Vesna; Lange, Michael D.; Yoshida, Wayne; Liu, Po-Hsin; Uyeda, Jansen; Barsky, Michael E.; Fung, Andy; Gaier, Todd; Lai, Richard

2007-12-01

49

positions): transistor,  

E-print Network

) . Biology & Medicine ­ 4 (psychoanalysis, penicillin, DNA, polio) . Physics & Astronomy ­ 3 (Einstein, Fermi, transistor, plastic, WWW) . Biology & Medicine ­ 4 (psychoanalysis, penicillin, DNA, polio) . Physics

Artemov, Sergei N.

50

High temperature current mirror amplifier  

DOEpatents

Disclosed is a high temperature current mirror amplifier having biasing means in the transdiode connection of the input transistor for producing a voltage to maintain the base-collector junction reversed-biased and a current means for maintaining a current through the biasing means at high temperatures so that the base-collector junction of the input transistor remained reversed-biased. For accuracy, a second current mirror is provided with a biasing means and current means on the input leg. 2 figs.

Patterson, R.B. III.

1984-05-22

51

Sense Amplifier-Based Pass Transistor Logic  

E-print Network

leakage current. . . . . . . . . . . . . . . . . . . . . . . . .leakage current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .leakage current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Alarcon, Louis Poblete

2010-01-01

52

Transferred substrate heterojunction bipolar transistors for submillimeter wave applications  

NASA Technical Reports Server (NTRS)

We present ongoing work towards the development of submillimeter wave transistors with goals of realizing advanced high frequency amplifiers, voltage controlled oscillators, active multipliers, and traditional high-speed digital circuits.

Fung, A.; Samoska, L.; Siegel, P.; Rodwell, M.; Urteaga, M.; Paidi, V.

2003-01-01

53

Graphene transistors.  

PubMed

Graphene has changed from being the exclusive domain of condensed-matter physicists to being explored by those in the electron-device community. In particular, graphene-based transistors have developed rapidly and are now considered an option for post-silicon electronics. However, many details about the potential performance of graphene transistors in real applications remain unclear. Here I review the properties of graphene that are relevant to electron devices, discuss the trade-offs among these properties and examine their effects on the performance of graphene transistors in both logic and radiofrequency applications. I conclude that the excellent mobility of graphene may not, as is often assumed, be its most compelling feature from a device perspective. Rather, it may be the possibility of making devices with channels that are extremely thin that will allow graphene field-effect transistors to be scaled to shorter channel lengths and higher speeds without encountering the adverse short-channel effects that restrict the performance of existing devices. Outstanding challenges for graphene transistors include opening a sizeable and well-defined bandgap in graphene, making large-area graphene transistors that operate in the current-saturation regime and fabricating graphene nanoribbons with well-defined widths and clean edges. PMID:20512128

Schwierz, Frank

2010-07-01

54

High-Speed, high-power, switching transistor  

NASA Technical Reports Server (NTRS)

Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.

Carnahan, D.; Ohu, C. K.; Hower, P. L.

1979-01-01

55

Development and Experimental Evaluation of an Automated Multi-Media Course on Transistors.  

ERIC Educational Resources Information Center

A completely automated multi-media self-study program for teaching a portion of electronic solid-state fundamentals was developed. The subject matter areas included were fundamental theory of transistors, transistor amplifier fundamentals, and simple mathematical analysis of transistors including equivalent circuits, parameters, and characteristic…

Whitted, J.H., Jr.; And Others

56

Transistor Effect in Improperly Connected Transistors.  

ERIC Educational Resources Information Center

Discusses the differences between the standard representation and a realistic representation of a transistor. Presents an experiment that helps clarify the explanation of the transistor effect and shows why transistors should be connected properly. (JRH)

Luzader, Stephen; Sanchez-Velasco, Eduardo

1996-01-01

57

Solid State Student Guide: Power Amplifier Lab  

NSDL National Science Digital Library

In this lab, the students will analyze four different classes of amplifiers and compare their efficiencies. Students will gain a better understanding of the functions of a transistor and how MOSFETs are implemented in power amplifiers. It should take about three hours to work through the entire lab exercise. The module may be downloaded in a Zipped file which contains a Microsoft Word Doc file. A quick, free login is required to access the materials.

58

Noiseless amplification in the optical transistor  

NASA Astrophysics Data System (ADS)

We apply a previously formulated theory of cavity-based phase-sensitive amplifiers to the case of single-ended Fabry-Perot cavity filled with a Kerr medium. We characterize the doma is better than that of the phase-insensitive linear amplifier, and identify the conditions under which noiseless amplification is possible. The best parametric conditions for noiseless amplification turn out to be close to those for best optical transistor operation.

Protsenko, I. E.; Lugiato, L. A.

1994-07-01

59

Switching Amplifiers  

NSDL National Science Digital Library

Created by Work-Ready Electronics, a project of the Advanced Technological Education, this module walks visitors through switching amplifiers. The site content is divided up into four sections: Switching Amplifiers Introduction, Class D Switching Amplifiers, Switching RF Power Amplifiers, and Troubleshooting. There is a quiz for each section to test what students learned in the module in the Knowledge Probe section, and the Learning Resources section contains four activities to help cement student understanding. There are also further resources - both print and Web based - for more information and two Questor games, a Flash quiz that reiterates the material covered. The Notebook function allows visitors to take notes and review them at any time. This is an excellent resource students and educators in electronics technician programs to introduce and explore switching amplifiers.

60

A Novel DAC Based Switching Power Amplifier for Polar Transmitter  

Microsoft Academic Search

A novel switching power amplifier based on the concept of digital to analog converter (DAC) is presented for polar transmitter architecture. The novel idea in this amplifier is to generate a current proportional to the amplitude modulation signal and the power control bits. The current is then up-converted to the frequency of interest using switching transistors. In this paper, we

Amin Shameli; Aminghasem Safarian; Ahmadreza Rofougaran; Maryam Rofougaran; Franco De Flaviis

2006-01-01

61

Matched wideband low-noise amplifiers for radio astronomy S. Weinreb, J. Bardin, H. Mani, and G. Jones  

E-print Network

Matched wideband low-noise amplifiers for radio astronomy S. Weinreb, J. Bardin, H. Mani, and G low noise amplifiers for the 0.3­4 GHz frequency range are described. The amplifiers can be operated temperature. One amplifier utilizes commercially available, plastic-packaged SiGe transistors for first

Weinreb, Sander

62

Phase noise modelling and optimisation of microwave SiGe amplifiers for sapphire oscillators applications  

E-print Network

Phase noise modelling and optimisation of microwave SiGe amplifiers for sapphire oscillators microwave SiGe bipolar transistors has been performed. Using these models, the phase noise of an amplifier software. Theoretical results are then compared to the experiment, both for a single stage amplifier

Boyer, Edmond

63

Test results for 20-GHz GaAs FET spacecraft power amplifier  

NASA Technical Reports Server (NTRS)

Test were conducted to measure the performance of the 20-GHz solid state, proof-of-concept amplifier. The amplifier operates over the 17.7 to 20.2-GHz frequency range and uses high power gallium arsenide field effect transistors. The amplifier design and test methods are briefly described. NASA and contractor performance data are compared.

Shalkhauser, K. A.

1985-01-01

64

Bidirectional amplifier  

DOEpatents

A bilateral circuit is operable for transmitting signals in two directions without generation of ringing due to feedback caused by the insertion of the circuit. The circuit may include gain for each of the signals to provide a bidirectional amplifier. The signals are passed through two separate paths, with a unidirectional amplifier in each path. A controlled sampling device is provided in each path for sampling the two signals. Any feedback loop between the two signals is disrupted by providing a phase displacement between the control signals for the two sampling devices.

Wright, James T. (Cedarcrest, NM)

1986-01-01

65

Amplified Policymaking  

ERIC Educational Resources Information Center

This brief examines the policy implications of two drivers of change presented in the "2020 Forecast: Creating the Future of Learning"-- Pattern Recognition and Amplified Organization. These drivers point toward a series of cultural shifts and illuminate how we are developing new ways of organizing, constructing, and managing knowledge.…

Prince, Katherine; Woempner, Carolyn

2010-01-01

66

Organic electrochemical transistors for clinical applications.  

PubMed

The ability of organic electrochemical transistors is explored to record human electrophysiological signals of clinical relevance. An organic electrochemical transistor (OECT) that shows a high (>1 mS) transconductance at zero applied gate voltage is used, necessitating only one power supply to bias the drain, while the gate circuit is driven by cutaneous electrical potentials. The OECT is successful in recording cardiac rhythm, eye movement, and brain activity of a human volunteer. These results pave the way for applications of OECTs as an amplifying transducer for human electrophysiology. PMID:25262967

Leleux, Pierre; Rivnay, Jonathan; Lonjaret, Thomas; Badier, Jean-Michel; Bénar, Christian; Hervé, Thierry; Chauvel, Patrick; Malliaras, George G

2015-01-01

67

EDITORIAL: Reigniting innovation in the transistor Reigniting innovation in the transistor  

NASA Astrophysics Data System (ADS)

Today the transistor is integral to the electronic circuitry that wires our lives. When Bardeen and Brattain first observed an amplified signal by connecting electrodes to a germanium crystal they saw that their 'semiconductor triode' could prove a useful alternative to the more cumbersome vacuum tubes used at the time [1]. But it was perhaps William Schottky who recognized the extent of the transistor's potential. A basic transistor has three or more terminals and current across one pair of terminals can switch or amplify current through another pair. Bardeen, Brattain and Schottky were jointly awarded a Nobel Prize in 1956 'for their researches on semiconductors and their discovery of the transistor effect' [2]. Since then many new forms of the transistor have been developed and understanding of the underlying properties is constantly advancing. In this issue Chen and Shih and colleagues at Taiwan National University and Drexel University report a pyroelectrics transistor. They show how a novel optothermal gating mechanism can modulate the current, allowing a range of developments in nanoscale optoelectronics and wireless devices [3]. The explosion of interest in nanoscale devices in the 1990s inspired electronics researchers to look for new systems that can act as transistors, such as carbon nanotube [4] and silicon nanowire [5] transistors. Generally these transistors function by raising and lowering an energy barrier of kBT -1, but researchers in the US and Canada have demonstrated that the quantum interference between two electronic pathways through aromatic molecules can also modulate the current flow [6]. The device has advantages for further miniaturization where energy dissipation in conventional systems may eventually cause complications. Interest in transistor technology has also led to advances in fabrication techniques for achieving high production quantities, such as printing [7]. Researchers in Florida in the US demonstrated field effect transistor behaviour in devices fabricated from chemically reduced graphene oxide. The work provided an important step forward for graphene electronics, which has been hampered by difficulties in scaling up the mechanical exfoliation techniques required to produce the high-quality graphene often needed for functioning devices [8]. In Sweden, researchers have developed a transistor design that they fabricate using standard III-V parallel processing, which also has great promise for scaling up production. Their transistor is based on a vertical array of InAs nanowires, which provide high electron mobility and the possibility of high-speed and low-power operation [9]. Different fabrication techniques and design parameters can influence the properties of transistors. Researchers in Belgium used a new method based on high-vacuum scanning spreading resistance microscopy to study the effect of diameter on carrier profile in nanowire transistors [10]. They then used experimental data and simulations to gain a better understanding of how this influenced the transistor performance. In Japan, Y Ohno and colleagues at Nagoya University have reported how atomic layer deposition of an insulating layer of HfO2 on carbon nanotube field effect transistors can change the carrier from p-type to n-type [11]. Carrier type switching—'ambipolar behaviour'—and hysteresis of carbon nanotube network transistors can make achieving reliable device performance challenging. However studies have also suggested that the hysteretic properties may be exploited in non-volatile memory applications. A collaboration of researchers in Italy and the US demonstrated transistor and memory cell behaviour in a system based on a carbon nanotube network [13]. Their device had relatively fast programming, good endurance and the charge retention was successfully enhanced by limiting exposure to air. Progress in understanding transistor behaviour has inspired other innovations in device applications. Nanowires are notoriously sensitive to gases such as CO, opening opportunities for applications in sensing using one-

Demming, Anna

2012-09-01

68

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-print Network

Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

Lee, Dong Seup

2014-01-01

69

A 100-element HBT grid amplifier  

Microsoft Academic Search

A 100-element 10-GHz grid amplifier has been developed. The active devices in the grid are chips with heterojunction-bipolar-transistor (HBT) differential pairs. The metal grid pattern was empirically designed to provide effective coupling between the HBTs and free space. Two independent measurements, one with focusing lenses and the other without, were used to characterize the grid. In each case, the peak

Moonil Kim; Emilio A. Sovero; Jonathan B. Hacker; Michael P. De Lisio; Jung-Chih Chiao; Shi-Jie Li; David R. Gagnon; James J. Rosenberg; David B. Rutledge

1993-01-01

70

Precision absolute value amplifier for a precision voltmeter  

DOEpatents

Bipolar inputs are afforded by the plus inputs of first and second differential input amplifiers. A first gain determining resister is connected between the minus inputs of the differential amplifiers. First and second diodes are connected between the respective minus inputs and the respective outputs of the differential amplifiers. First and second FETs have their gates connected to the outputs of the amplifiers, while their respective source and drain circuits are connected between the respective minus inputs and an output lead extending to a load resister. The output current through the load resister is proportional to the absolute value of the input voltage difference between the bipolar input terminals. A third differential amplifier has its plus input terminal connected to the load resister. A second gain determining resister is connected between the minus input of the third differential amplifier and a voltage source. A third FET has its gate connected to the output of the third amplifier. The source and drain circuit of the third transistor is connected between the minus input of the third amplifier and a voltage-frequency converter, constituting an output device. A polarity detector is also provided, comprising a pair of transistors having their inputs connected to the outputs of the first and second differential amplifiers. The outputs of the polarity detector are connected to gates which switch the output of the voltage-frequency converter between up and down counting outputs.

Hearn, William E. (Berkeley, CA); Rondeau, Donald J. (El Sobrante, CA)

1985-01-01

71

Imperial College London EEE 1L6 Autumn 2009 E2.2 Analogue Electronics Multiple stage amplifiers  

E-print Network

Imperial College London ­ EEE 1L6 Autumn 2009 E2.2 Analogue Electronics Multiple stage amplifiers amplifiers #12;Imperial College London ­ EEE 2L6 Autumn 2009 E2.2 Analogue Electronics Two stage BJT of 2 single stage transistor amplifiers. We will study the shaded ones. #12;Imperial College London

Papavassiliou, Christos

72

Protection circuit for high power amplifiers operating under mismatch conditions  

Microsoft Academic Search

A protection circuit is developed which protects transistors in the output stage of a high power amplifier against voltage breakdown as a result of mismatch. The circuit is applied in an S-band and X-band High Power Amplifier and measured under various mismatch conditions. The devices have been developed in the 6-inch 0.5 mum GaAs power pHEMT process (PP50-11) of WIN

G. van der Bent; M. van Wanum; A. P. de Hek; M. W. van der Graaf; F. E. van Vliet

2007-01-01

73

A very high frequency CMOS Variable Gain Amplifier  

E-print Network

. Linearity of the transconductor B. Source degeneration amplifier C. Analog multiplier. D. Differential pair with diode-connected load. . . . . E. Conclusions 6 8 10 . . . 12 17 HIGH SWING CURRENT MIRROR. 19 A. DC characteristics . B. Bias... level . . . . Page 2 Block diagram of a direct conversion receiver. 3 Single transistor transconductor 4 Differential pair 5 Source degeneration amplifier. 6 Four-quadrant multiplier basic architectures . . . . . . . . 10 7 Multiplier as a...

Tan, Siang Tong

2001-01-01

74

Optical Amplifiers for Telecommunications  

Microsoft Academic Search

This paper reviews optical amplifier technologies for telecommunications networks. The operation and applications of erbium doped fibre amplifiers (EDFAs), fibre Raman amplifiers (FRAs), erbium doped waveguide amplifiers (EDWAs) and semiconductor optical amplifiers (SOAs) are described. The factors that influence their gain, operating bandwidths, spectral profiles and noise are also discussed.

P. Urquhart; O. G. Lopez; G. Boyen; A. Bruckmann

2007-01-01

75

Crystal oscillators using negative voltage gain, single pole response amplifiers  

NASA Technical Reports Server (NTRS)

A simple and inexpensive crystal oscillator is provided which employs negative voltage gain, single pole response amplifiers. The amplifiers may include such configurations as gate inverters, operational amplifiers and conventional bipolar transistor amplifiers, all of which operate at a frequency which is on the roll-off portion of their gain versus frequency curve. Several amplifier feedback circuit variations are employed to set desired bias levels and to allow the oscillator to operate at the crystal's fundamental frequency or at an overtone of the fundamental frequency. The oscillator is made less expensive than comparable oscillators by employing relatively low frequency amplifiers and operating them at roll-off, at frequencies beyond which they are customarily used. Simplicity is provided because operation at roll-off eliminates components ordinarily required in similar circuits to provide sufficient phase-shift in the feedback circuitry for oscillation to occur.

Kleinberg, Leonard L. (Inventor)

1989-01-01

76

Fluctuation dynamo amplified  

E-print Network

Fluctuation dynamo amplified by intermittent shear bursts J. Pratt The Fluctuation Dynamo Boussinesq MHD Convection Simulations Shear Bursts: Amplified Energy Production Magnetic Helicity Fluctuation dynamo amplified by intermittent shear bursts J. Pratt Thanks to my collaborators: A. Busse (U. Glasgow

77

Transistors: The Field Effect  

NSDL National Science Digital Library

Transistors are the building blocks of modern electronic devices. Your cell phones, iPods, and computers all depend on them to operate. Thanks to today's microfabrication technology, transistors can be made very tiny and be massively produced. You are probably using billions of them while working with this activity now--as of 2006, a dual-core Intel microprocessor contains 1.7 billion transistors. The field effect transistor is the most common type of transistor. So we will focus on it in this activity.

The Concord Consortium

2011-12-11

78

MMIC Amplifier Produces Gain of 10 dB at 235 GHz  

NASA Technical Reports Server (NTRS)

The first solid-state amplifier capable of producing gain at a frequency >215 GHz has been demonstrated. This amplifier was fabricated as a monolithic microwave integrated-circuit (MMIC) chip containing InP high-electron-mobility transistors (HEMTs) of 0.07 micron gate length on a 50- m-thick InP substrate.

Dawson, Douglas; Fung, King Man; Lee, Karen; Samoska, Lorene; Wells, Mary; Gaier, Todd; Kangaslahti, Pekka; Grundbacher, Ronald; Lai, Richard; Raja, Rohit; Liu, Po-Hsin

2007-01-01

79

X-Band, 17-Watt Solid-State Power Amplifier  

NASA Technical Reports Server (NTRS)

An advanced solid-state power amplifier that can generate an output power of as much as 17 W at a design operating frequency of 8.4 GHz has been designed and constructed as a smaller, lighter, less expensive alternative to traveling-wave-tube X-band amplifiers and to prior solid-state X-band power amplifiers of equivalent output power. This amplifier comprises a monolithic microwave integrated circuit (MMIC) amplifier module and a power-converter module integrated into a compact package (see Figure 1). The amplifier module contains an input variable-gain amplifier (VGA), an intermediate driver stage, a final power stage, and input and output power monitors (see Figure 2). The VGA and the driver amplifier are 0.5-m GaAs-based metal semiconductor field-effect transistors (MESFETs). The final power stage contains four parallel high-efficiency, GaAs-based pseudomorphic high-electron-mobility transistors (PHEMTs). The gain of the VGA is voltage-variable over a range of 10 to 24 dB. To provide for temperature compensation of the overall amplifier gain, the gain-control voltage is generated by an operational-amplifier circuit that includes a resistor/thermistor temperature-sensing network. The driver amplifier provides a gain of 14 dB to an output power of 27 dBm to drive the four parallel output PHEMTs, each of which is nominally capable of putting out as much as 5 W. The driver output is sent to the input terminals of the four parallel PHEMTs through microstrip power dividers; the outputs of these PHEMTs are combined by microstrip power combiners (which are similar to the microstrip power dividers) to obtain the final output power of 17 W.

Mittskus, Anthony; Stone, Ernest; Boger, William; Burgess, David; Honda, Richard; Nuckolls, Carl

2005-01-01

80

Near-field thermal transistor  

E-print Network

Using a block of three separated solid elements, a thermal source and drain together with a gate made of an insulator-metal transition material exchanging near-field thermal radiation, we introduce a nanoscale analog of a field-effect transistor which is able to control the flow of heat exchanged by evanescent thermal photons between two bodies. By changing the gate temperature around its critical value, the heat flux exchanged between the hot body (source) and the cold body (drain) can be reversibly switched, amplified, and modulated by a tiny action on the gate. Such a device could find important applications in the domain of nanoscale thermal management and it opens up new perspectives concerning the development of contactless thermal circuits intended for information processing using the photon current rather than the electric current.

Ben-Abdallah, Philippe

2013-01-01

81

High-Efficiency Amplifiers Using AlGaN\\/GaN HEMTs on SiC  

Microsoft Academic Search

GaN HEMTs on SiC are applied to high-efficiency power amplifier designs. Several class-E hybrid power amplifiers based on the GaN HEMT cell were designed and tested. Around 2 GHz, the first amplifier provides 10 watts CW with associated PAE of 85% and gain of 12 dB. Other higher frequency designs with the same transistor cell provide 10 watts and 80%

Scott Sheppard; Bill Pribble; R. Peter Smith; Adam Saxler; Scott Allen; Jim Milligan; Ray Pengelly

2006-01-01

82

Optical amplifiers for telecommunications  

Microsoft Academic Search

The paper contains the results of simulation of Raman optical amplifiers with copropagating and counterpropagating pumping. The computer program was developed to calculate signals and noise of amplified spontaneous emission for various lengths of amplifier sections. The various applications of optical amplifiers allowing to increase regenerator section length are considered. The results of calculations are of interest to the designers

Maria S. Bylina; Sergey F. Glagolev

2008-01-01

83

Amplified quantum transforms  

NASA Astrophysics Data System (ADS)

In this thesis we investigate two new Amplified Quantum Transforms. In particular we create and analyze the Amplified Quantum Fourier Transform (Amplified-QFT) and the Amplified-Haar Wavelet Transform. The Amplified-QFT algorithm is used to solve the Local Period Problem. We calculate the probabilities of success and compare this algorithm with the QFT and QHS algorithms. We also examine the Amplified-QFT algorithm for solving the Local Period Problem with Error Stream. We use the Amplified-Haar Wavelet Transform for solving the Local Constant or Balanced Signal Decision Problem which is a generalization of the Deutsch-Jozsa problem.

Cornwell, David J.

84

The Transistor Museum  

NSDL National Science Digital Library

The Transistor Museum is a fascinating site "dedicated to preserving the history of the greatest invention of the 20th century." The museum's front page mentions some remarkable facts and quotes that demonstrate the importance of the transistor in modern life. Visitors can read transcripts of lectures, oral histories, and short biographies of notable individuals who played a role in the development of transistor applications. An impressive photo gallery showcases some of the most prominent historical transistors, while providing information about their usage, type, date of introduction, and other interesting notes.

2002-01-01

85

MOSFET's for Cryogenic Amplifiers  

NASA Technical Reports Server (NTRS)

Study seeks ways to build transistors that function effectively at liquid-helium temperatures. Report discusses physics of metaloxide/semiconductor field-effect transistors (MOSFET's) and performances of these devices at cryogenic temperatures. MOSFET's useful in highly sensitive cryogenic preamplifiers for infrared astronomy.

Dehaye, R.; Ventrice, C. A.

1987-01-01

86

Hybrid matrix amplifier  

SciTech Connect

The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N.times.M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise.

Martens, Jon S. (Sunnyvale, CA); Hietala, Vincent M. (Placitas, NM); Plut, Thomas A. (Albuquerque, NM)

1995-01-01

87

Hybrid matrix amplifier  

SciTech Connect

The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N[times]M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise. 6 figures.

Martens, J.S.; Hietala, V.M.; Plut, T.A.

1995-01-03

88

431 531 Class Notes 5 5 Transistors and Transistor Circuits  

E-print Network

431 531 Class Notes 5 5 Transistors and Transistor Circuits Although I will not follow the text in detail for the discussion of transistors, I will follow the text's philosophy. Unless one gets into device fabrication, it is generally not important to understand the inner workings of transistors

Frey, Raymond E.

89

Reduced-dimension transistors: Reduced-dimension transistors  

E-print Network

1 Reduced-dimension transistors: the HEMT LECTURE 20 · Reduced-dimension transistors · HEMT · 2-D;2 Examples of 3-, 2- and 1-D transistors #12;3 High electron-mobility Transistor · Note the Schottky barrier

Pulfrey, David L.

90

Printed Organic Transistors  

Microsoft Academic Search

We use scalable printing technology in the fabrication of the organic transistors. We formulated printable conducting layers that can be imaged onto a transistor structures forming source and drains lines with 10 micron wide channels. The performance of printed transisors compare compare favorable with those prepared using metal contacts evaporated via shadow mask

Graciela Blanchet; Gao Feng; Curtis Fincher; John Rogers; Loo Lin

2002-01-01

91

Electrolytic Analog Transistor  

Microsoft Academic Search

The electrolytic analog transistor is an operating model of the junction transistor which substitutes the reduced and oxidized forms of ions in solution for electrons and holes in a semiconductor. A base electrode makes a low-resistance contact to the solution and also serves to maintain the ratio of oxidized and reduced ions at an equilibrium value, thus establishing the potential

Harry Letaw Jr.; John Bardeen

1954-01-01

92

Portable musical instrument amplifier  

DOEpatents

The present invention relates to a musical instrument amplifier which is particularly useful for electric guitars. The amplifier has a rigid body for housing both the electronic system for amplifying and processing signals from the guitar and the system's power supply. An input plug connected to and projecting from the body is electrically coupled to the signal amplifying and processing system. When the plug is inserted into an output jack for an electric guitar, the body is rigidly carried by the guitar, and the guitar is operatively connected to the electrical amplifying and signal processing system without use of a loose interconnection cable. The amplifier is provided with an output jack, into which headphones are plugged to receive amplified signals from the guitar. By eliminating the conventional interconnection cable, the amplifier of the present invention can be used by musicians with increased flexibility and greater freedom of movement.

Christian, David E. (Danbury, CT)

1990-07-24

93

Gain and switching in the spin-flip transistor  

NASA Astrophysics Data System (ADS)

The transport properties of multi-terminal magnetoelectronic structures in the diffuse regime can be calculated conveniently by magnetoelectronic circuit theory [1]. The "spin-flip transistor" is a device consisting of a normal metal node and three ferromagnetic contacts with magnetization directions that can be rotated freely. We discuss the circuit theory of the spin-flip transistor when used as current or voltage amplifier, as a memory element, or spin injector. [1] A. Brataas, Yu.V. Nazarov, and G.E.W. Bauer, Phys. Rev. Lett. 84, 2481 (2000).

Bauer, Gerrit E. W.; Brataas, Arne; Tserkovnyak, Yaroslav

2003-03-01

94

Single Photon Transistor Brad Martin  

E-print Network

Single Photon Transistor Brad Martin PH 464 #12;Brad Martin Single Photon Transistor 1 Abstract The concept of an optical transistor is not a new one. The difficulty with building optical devices that use in the nanowire. This concept can be extended to create an optical transistor device in which "current"(a flow

La Rosa, Andres H.

95

Wideband DMOS amplifier competes with bipolars  

NASA Astrophysics Data System (ADS)

A wideband (40-350 MHz) hybrid DMOS or double-diffused metal oxide semiconductor amplifier is described that has been designed and built to demonstrate the feasibility of the device in cable communications systems (currently dominated by bipolar hybrid IC). The advantages of the DMOS transistor include high input impedance, high current gain and power gain, and no thermal runaway problems. Furthermore, in a DMOS, a very short channel length (a micron or less) is possible without submicrometer lithography, and a high breakdown voltage can be obtained and tailored independently of the channel length by incorporating a lightly doped drift region between the active region and the drain contact. Three circuit configurations were investigated: multiple feedback, cascode, and cascade. Thick-film technology was used to implement the circuit. Amplifier characteristics are tabulated.

Salama, C. A. T.; Sin, J. K. O.

1986-06-01

96

Electronics Operational Amplifiers  

E-print Network

ECEN 325 Electronics Operational Amplifiers Dr. Aydin Ilker Kar¸silayan Texas A&M University Electronics - Aydin I. Kar¸silayan - Operational Amplifiers 1 #12;Equivalent CircuitEquivalent Circuit i=0 i=0 Electronics - Aydin I. Kar¸silayan - Operational Amplifiers 2 #12;vo vs. vdvo vs. vd Slope = A SAT vd vp vn

Palermo, Sam

97

Common base amplifier with 7 - dB gain at 176 GHz in InP mesa DHBT technology  

NASA Technical Reports Server (NTRS)

We report a single stage tunded amplifier that exhibits 7 dB small signal gain at 176 GHz. Common Base topology is chosen as it has the best maximum stable gain (MSG) in this frequency band when compared to common emitter and common collector topologies. The amplifiers are designed and fabricated in InP mesa double heterojunction bipolar transistor (DHBT) technology.

Samoska, Lorene; Paidi, V.; Griffith, Z.; Dahlstrom, M.; Wei, Y.; Urteaga, M.; Rodell, M. J. W.; Fung, A.

2004-01-01

98

Bandwidth extension for ultra-wideband CMOS low-noise amplifiers  

Microsoft Academic Search

Techniques are proposed to enhance the bandwidth of ultra-wideband (UWB) CMOS low-noise amplifiers (LNA). By using multiple-input-branch technique and resistive shunt- feedback technique, LNA could achieve ultra-wideband input impedance matching with small noise figure degradation. The gain bandwidth is enhanced by an L type inter-stage matching network between the input transistors and the cascode transistor which could enhance both the

Baoyong Chi; Chun Zhang; Zhihua Wang

2008-01-01

99

From The Lab to The Fab: Transistors to Integrated Circuits  

NASA Astrophysics Data System (ADS)

Transistor action was experimentally observed by John Bardeen and Walter Brattain in n-type polycrystalline germanium on December 16, 1947 (and subsequently polycrystalline silicon) as a result of the judicious placement of gold-plated probe tips in nearby single crystal grains of the polycrystalline material (i.e., the point-contact semiconductor amplifier, often referred to as the point-contact transistor).The device configuration exploited the inversion layer as the channel through which most of the emitted (minority) carriers were transported from the emitter to the collector. The point-contact transistor was manufactured for ten years starting in 1951 by the Western Electric Division of AT&T. The a priori tuning of the point-contact transistor parameters, however, was not simple inasmuch as the device was dependent on the detailed surface structure and, therefore, very sensitive to humidity and temperature as well as exhibiting high noise levels. Accordingly, the devices differed significantly in their characteristics and electrical instabilities leading to "burnout" were not uncommon. With the implementation of crystalline semiconductor materials in the early 1950s, however, p-n junction (bulk) transistors began replacing the point-contact transistor, silicon began replacing germanium and the transfer of transistor technology from the lab to the lab accelerated. We shall review the historical route by which single crystalline materials were developed and the accompanying methodologies of transistor fabrication, leading to the onset of the Integrated Circuit (IC) era. Finally, highlights of the early years of the IC era will be reviewed from the 256 bit through the 4M DRAM. Elements of IC scaling and the role of Moore's Law in setting the parameters by which the IC industry's growth was monitored will be discussed.

Huff, Howard R.

2003-09-01

100

Update on Waveguide-Embedded Differential MMIC Amplifiers  

NASA Technical Reports Server (NTRS)

There is an update on the subject matter of Differential InP HEMT MMIC Amplifiers Embedded in Waveguides (NPO-42857) NASA Tech Briefs, Vol. 33, No. 9 (September 2009), page 35. To recapitulate: Monolithic microwave integrated-circuit (MMIC) amplifiers of a type now being developed for operation at frequencies of hundreds of gigahertz contain InP high-electron-mobility transistors (HEMTs) in a differential configuration. The MMICs are designed integrally with, and embedded in, waveguide packages. The instant work does not mention InP HEMTs but otherwise reiterates part of the subject matter of the cited prior article, with emphasis on the following salient points: An MMIC is mounted in the electric-field plane ("E-plane") of a waveguide and includes a finline transition to each differential-amplifier stage. The differential configuration creates a virtual ground within each pair of transistor-gate fingers, eliminating the need for external radio-frequency grounding. This work concludes by describing a single-stage differential submillimeter-wave amplifier packaged in a rectangular waveguide and summarizing results of tests of this amplifier at frequencies of 220 and 305 GHz.

Kangaslahti, Pekka; Schleht, Erich

2010-01-01

101

Printed inorganic transistors  

E-print Network

Forty years of exponential growth of semiconductor technology have been predicated on the miniaturization of the transistors that comprise integrated circuits. While complexity has greatly increased within a given area of ...

Ridley, Brent (Brent Alan), 1974-

2003-01-01

102

The resonant gate transistor  

Microsoft Academic Search

A device is described which permits high-Qfrequency selection to be incorporated into silicon integrated circuits. It is essentially an electrostatically excited tuning fork employing field-effect transistor \\

HARVEY C. NATHANSON; WILLIAM E. NEWELL; ROBERT A. WICKSTROM

1967-01-01

103

The Transistor Game  

NSDL National Science Digital Library

In this game, your job working at a Transistor Recycling Centre is to ensure that only items containing transistors are sent to the recycling machine. Goods enter the recycling machine via a conveyer belt, and you must remove all the items that do not contain transistors. You are awarded one point for each item that you correctly remove from the belt. If you mistakenly remove an item with a transistor, two points will be deducted from your total score. The game has an infinite number of levels, and you will be evaluated at the end of each level. When you have completed one level you can move onto the next, in which the belt moves faster and there will be new items to sort. If you're really skilled you could become this month's super recycler!

104

High Power Switching Transistor  

NASA Technical Reports Server (NTRS)

Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

1983-01-01

105

An ultrawideband spin-wave medium-power chaos generator based on field-effect transistors  

NASA Astrophysics Data System (ADS)

A prototype of an ultrawideband (UWB) microwave chaos generator based on a nonlinear spin-wave transmission line, a multistage transistor amplifier with an output amplifier based on GaAs field-effect transistors, and a microstrip bandpass filter was constructed. The possibility of autonomous generation of a UWB chaotic microwave signal with a central frequency of 3 GHz and a total power of about 4 W in a frequency band exceeding 30% was demonstrated. The proposed chaos generator is characterized by a fairly high efficiency of about 20%.

Grishin, S. V.; Grishin, V. S.; Romanenko, D. V.; Sharaevskii, Yu. P.

2014-10-01

106

Transistor-based interface circuitry  

DOEpatents

Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

Taubman, Matthew S. (Richland, WA)

2007-02-13

107

Transistor-based interface circuitry  

DOEpatents

Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

Taubman, Matthew S. (Richland, WA)

2004-02-24

108

Wireless Josephson amplifier  

SciTech Connect

Josephson junction parametric amplifiers are playing a crucial role in the readout chain in superconducting quantum information experiments. However, their integration with current 3D cavity implementations poses the problem of transitioning between waveguide, coax cables, and planar circuits. Moreover, Josephson amplifiers require auxiliary microwave components, like directional couplers and/or hybrids, that are sources of spurious losses and impedance mismatches that limit measurement efficiency and amplifier tunability. We have developed a wireless architecture for these parametric amplifiers that eliminates superfluous microwave components and interconnects. This greatly simplifies their assembly and integration into experiments. We present an experimental realization of such a device operating in the 9–11?GHz band with about 100?MHz of amplitude gain-bandwidth product, on par with devices mounted in conventional sample holders. The simpler impedance environment presented to the amplifier also results in increased amplifier tunability.

Narla, A.; Sliwa, K. M.; Hatridge, M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

2014-06-09

109

Flexible Black Phosphorus Ambipolar Transistors, Circuits and AM Demodulator.  

PubMed

High-mobility two-dimensional (2D) semiconductors are desirable for high-performance mechanically flexible nanoelectronics. In this work, we report the first flexible black phosphorus (BP) field-effect transistors (FETs) with electron and hole mobilities superior to what has been previously achieved with other more studied flexible layered semiconducting transistors such as MoS2 and WSe2. Encapsulated bottom-gated BP ambipolar FETs on flexible polyimide afforded maximum carrier mobility of about 310 cm(2)/V·s with field-effect current modulation exceeding 3 orders of magnitude. The device ambipolar functionality and high-mobility were employed to realize essential circuits of electronic systems for flexible technology including ambipolar digital inverter, frequency doubler, and analog amplifiers featuring voltage gain higher than other reported layered semiconductor flexible amplifiers. In addition, we demonstrate the first flexible BP amplitude-modulated (AM) demodulator, an active stage useful for radio receivers, based on a single ambipolar BP transistor, which results in audible signals when connected to a loudspeaker or earphone. Moreover, the BP transistors feature mechanical robustness up to 2% uniaxial tensile strain and up to 5000 bending cycles. PMID:25715122

Zhu, Weinan; Yogeesh, Maruthi N; Yang, Shixuan; Aldave, Sandra H; Kim, Joon-Seok; Sonde, Sushant; Tao, Li; Lu, Nanshu; Akinwande, Deji

2015-03-11

110

Development of a HgCdTe photomixer and impedance matched GaAs FET amplifier  

NASA Technical Reports Server (NTRS)

A research program for the development of a 10.6 micron HgCdTe photodiode/GaAs field effect transistor amplifier package for use at cryogenic temperatures (77k). The photodiode/amplifier module achieved a noise equivalent power per unit bandwidth of 5.7 times 10 to the 20th power W/Hz at 2.0 GHz. The heterodyne sensitivity of the HgCdTe photodiode was improved by designing and building a low noise GaAs field effect transistor amplifier operating at 77K. The Johnson noise of the amplifier was reduced at 77K, and thus resulted in an increased photodiode heterodyne sensitivity.

Shanley, J. F.; Paulauskas, W. A.; Taylor, D. R.

1982-01-01

111

Teaching the Common Emitter Amplifier.  

ERIC Educational Resources Information Center

Describes experiments in which a bipolar transistor is used to examine the behavior of a simple circuit. Also addresses problems in teaching the related concepts. (The experiments can be modified to incorporate devices other than bipolar transistors.) (JN)

Ellse, Mark D.

1984-01-01

112

10.0 Operational Amplifiers 1 of 25 Differential Amplifiers  

E-print Network

10.0 Operational Amplifiers 1 of 25 Differential Amplifiers #12;10.0 Operational Amplifiers 2 of 25 #12;10.0 Operational Amplifiers 3 of 25 Single Input ­ Single Output Gain Single Input ­ Differential Output Gain Difference Input ­ Dual Output Gain Common Mode Gain #12;10.0 Operational Amplifiers 4 of 25

Allen, Gale

113

Tanh cascode cell amplifier an arbitrary transfer characteristics amplifier  

E-print Network

Tanh cascode cell amplifier ­ an arbitrary transfer characteristics amplifier M. Ding and K.G. Gard An arbitrary transfer characteristic (TC) amplifier, called the tanh cascode cell (TCC) amplifier, is reported. This novel amplifier is capable of synthesising an arbitrary TC including the ideal rectifier transfer

114

LABORATORY 4 Amplifier Design Using Operational Amplifiers (OP-AMPs)  

E-print Network

ELEC 225 LABORATORY 4 Amplifier Design Using Operational Amplifiers (OP-AMPs) In ELEC 120, you designed circuits using the LM35 temperature sensor, DC fan, 741 operational amplifier, OPA 551 operational amplifier, and Light Emitting Diodes (LEDs). In this lab, we will focus on the design of an amplifier

Kozick, Richard J.

115

Chip-level spray cooling of an LD-MOSFET RF power Amplifier  

Microsoft Academic Search

We report here the application of water spray cooling directly to the top surface of a lateral diffused metal oxide semiconductor field effect transistor (LD-MOSFET) in a 500-MHz RF power amplifier. With the amplifier running in Class A, spray cooling at a flow of 0.14 l\\/min increases the output power from 66 W to 84 W, and the power-added efficiency

A. C. Cotler; E. R. Brown; V. Dhir; M. C. Shaw

2004-01-01

116

Miniature Spaceborne S and K\\/sub u\\/Band Low Noise Amplifiers for TDRSS  

Microsoft Academic Search

Light weight, miniature spaceborne parametric and transistor low noise amplifiers (LNA's) have been developed for TRW and Western Union for use in NASA's Tracking and Data Relay Satellite System (TDRSS). The S and Ku-Band LNA's each employ a single stage parametric amplifier and provide state-of-the-art noise temperatures of less than 65K and 140K over their respective 2.2-2.3 GHz and 14.89-15.12

C. Allen; J. D. Gruyl; P. Lombardo; E. Ng; H. Okean

1978-01-01

117

Broadband linearization of InGaP\\/GaAs HBT power amplifier  

Microsoft Academic Search

High linearity over a broad frequency band is a requirement in many RF amplifier designs. This paper shows that adding low impedance terminations at the envelope frequency (?2-?1) to the input of a Gallium Arsenide (GaAs) Heterojunction Bipolar Transistor (HBT) Distributed Amplifier (DA) improves the third order output intercept point (OIP3) over a bandwidth of 0.5 GHz to 3 GHz

Minghao Koh; Grant A. Ellis; Chin Soon Teoh

2010-01-01

118

Linearly polarized fiber amplifier  

DOEpatents

Optically pumped rare-earth-doped polarizing fibers exhibit significantly higher gain for one linear polarization state than for the orthogonal state. Such a fiber can be used to construct a single-polarization fiber laser, amplifier, or amplified-spontaneous-emission (ASE) source without the need for additional optical components to obtain stable, linearly polarized operation.

Kliner, Dahv A.; Koplow, Jeffery P.

2004-11-30

119

Dye laser amplifier  

DOEpatents

An improved dye laser amplifier is disclosed. The efficiency of the dye laser amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant. 3 figs.

Moses, E.I.

1992-12-01

120

ULTRAHIGH-SPEED DIPOLAR TRANSISTORS  

E-print Network

ULTRAHIGH-SPEED DIPOLAR TRANSISTORS Understanding nonequilibrium electron transport in Ill-V compound semiconductors has helped in the development of the fastest bipolar transistors. A. F. J. Levi, R. N. Noltenburg, Y. K. Chen and M. B. Panish The invention of the transistor in the late 1940s has had

Levi, Anthony F. J.

121

Broadband linear high-voltage amplifier for radio frequency ion traps.  

PubMed

We developed a linear high-voltage amplifier for small capacitive loads consisting of a high-voltage power supply and a transistor amplifier. With this cost-effective circuit including only standard parts sinusoidal signals with a few volts can be amplified to 1.7 kVpp over a usable frequency range at large-signal response spanning four orders of magnitude from 20 Hz to 100 kHz under a load of 10 pF. For smaller output voltages the maximum frequency shifts up to megahertz. We test different capacitive loads to probe the influence on the performance. The presented amplifier is sustained short-circuit proof on the output side, which is a significant advantage over other amplifier concepts. The amplifier can be used to drive radio frequency ion traps for single charged nano- and microparticles, which will be presented in brief. PMID:25430133

Kuhlicke, Alexander; Palis, Klaus; Benson, Oliver

2014-11-01

122

Nanowire transistors without junctions.  

PubMed

All existing transistors are based on the use of semiconductor junctions formed by introducing dopant atoms into the semiconductor material. As the distance between junctions in modern devices drops below 10 nm, extraordinarily high doping concentration gradients become necessary. Because of the laws of diffusion and the statistical nature of the distribution of the doping atoms, such junctions represent an increasingly difficult fabrication challenge for the semiconductor industry. Here, we propose and demonstrate a new type of transistor in which there are no junctions and no doping concentration gradients. These devices have full CMOS functionality and are made using silicon nanowires. They have near-ideal subthreshold slope, extremely low leakage currents, and less degradation of mobility with gate voltage and temperature than classical transistors. PMID:20173755

Colinge, Jean-Pierre; Lee, Chi-Woo; Afzalian, Aryan; Akhavan, Nima Dehdashti; Yan, Ran; Ferain, Isabelle; Razavi, Pedram; O'Neill, Brendan; Blake, Alan; White, Mary; Kelleher, Anne-Marie; McCarthy, Brendan; Murphy, Richard

2010-03-01

123

Low-Noise MMIC Amplifiers for 120 to 180 GHz  

NASA Technical Reports Server (NTRS)

Three-stage monolithic millimeter-wave integrated-circuit (MMIC) amplifiers capable of providing useful amounts of gain over the frequency range from 120 to 180 GHz have been developed as prototype low-noise amplifiers (LNAs) to be incorporated into instruments for sensing cosmic microwave background radiation. There are also potential uses for such LNAs in electronic test equipment, passive millimeter- wave imaging systems, radar receivers, communication receivers, and systems for detecting hidden weapons. The main advantage afforded by these MMIC LNAs, relative to prior MMIC LNAs, is that their coverage of the 120-to-180-GHz frequency band makes them suitable for reuse in a wider variety of applications without need to redesign them. Each of these MMIC amplifiers includes InP transistors and coplanar waveguide circuitry on a 50- mthick chip (see Figure 1). Coplanar waveguide transmission lines are used for both applying DC bias and matching of input and output impedances of each transistor stage. Via holes are incorporated between top and bottom ground planes to suppress propagation of electromagnetic modes in the substrate. On the basis of computational simulations, each of these amplifiers was expected to operate with a small-signal gain of 14 dB and a noise figure of 4.3 dB. At the time of writing this article, measurements of noise figures had not been reported, but on-chip measurements had shown gains approaching their simulated values (see Figure 2).

Pukala, David; Samoska, Lorene; Peralta, Alejandro; Bayuk, Brian; Grundbacher, Ron; Oliver, Patricia; Cavus, Abdullah; Liu, Po-Hsin

2009-01-01

124

Analysis of low-offset CTIA amplifier for small-size-pixel infrared focal plane array  

NASA Astrophysics Data System (ADS)

The design of input stage amplifier becomes more and more difficult as the expansion of format arrays and reduction of pixel size. A design method of low-offset amplifier based on 0.18-?m process used in small-size pixel is analyzed in order to decrease the dark signal of extended wavelength InGaAs infrared focal plane arrays (IRFPA). Based on an example of a cascode operational amplifier (op-amp), the relationship between input offset voltage and size of each transistor is discussed through theoretical analysis and Monte Carlo simulation. The results indicate that input transistors and load transistors have great influence on the input offset voltage while common-gate transistors are negligible. Furthermore, the offset voltage begins to increase slightly when the width and length of transistors decrease along with the diminution of pixel size, and raises rapidly when the size is smaller than a proximate threshold value. The offset voltage of preamplifiers with differential architecture and single-shared architecture in small pitch pixel are studied. After optimization under same conditions, simulation results show that single-shared architecture has smaller offset voltage than differential architecture.

Zhang, Xue; Huang, Zhangcheng; Shao, Xiumei

2014-11-01

125

Polariton Condensate Transistor Switch  

E-print Network

A polariton condensate transistor switch is realized through optical excitation of a microcavity ridge with two beams. The ballistically ejected polaritons from a condensate formed at the source are gated using the 20 times weaker second beam to switch on and off the flux of polaritons. In the absence of the gate beam the small built-in detuning creates potential landscape in which ejected polaritons are channelled toward the end of the ridge where they condense. The low loss photon-like propagation combined with strong nonlinearities associated with their excitonic component makes polariton based transistors particularly attractive for the implementation of all-optical integrated circuits.

Gao, T; Liew, T C H; Tsintzos, S I; Stavrinidis, G; Deligeorgis, G; Hatzopoulos, Z; Savvidis, P G

2012-01-01

126

Universal signal conditioning amplifier  

NASA Technical Reports Server (NTRS)

A state-of-the-art instrumentation amplifier capable of being used with most types of transducers has been developed at the Kennedy Space Center. This Universal Signal Conditioning Amplifier (USCA) can eliminate costly measurement setup item and troubleshooting, improve system reliability and provide more accurate data than conventional amplifiers. The USCA can configure itself for maximum resolution and accuracy based on information read from a RAM chip attached to each transducer. Excitation voltages or current are also automatically configured. The amplifier uses both analog and digital state-of-the-art technology with analog-to-digital conversion performed in the early stages in order to minimize errors introduced by offset and gain drifts in the analog components. A dynamic temperature compensation scheme has been designed to achieve and maintain 12-bit accuracy of the amplifier from 0 to 70 C. The digital signal processing section allows the implementation of digital filters up to 511th order. The amplifier can also perform real-time linearizations up to fourth order while processing data at a rate of 23.438 kS/s. Both digital and analog outputs are available from the amplifier.

Medelius, Pedro J.; Hallberg, Carl; Cecil, Jim

1994-01-01

127

Development of a low-noise amplifier for neutron detection in harsh environment  

NASA Astrophysics Data System (ADS)

A fast matching charge amplifier for neutron spectroscopy in harsh environment has been developed and tested at the JET Tokamak. This front-end circuit is capable to operate at a distance up to 100 meters from a sensor without increasing its equivalent noise charge. Further improvements are possible by exploiting the intrinsic performance of silicon-germanium bipolar junction transistors.

Angelone, M.; Cardarelli, R.; Paolozzi, L.; Pillon, M.

2014-10-01

128

An optically isolated amplifier  

NASA Astrophysics Data System (ADS)

The design presented was used for biomedical signal detection and monitoring. The amplifier was successfully applied for EMG and ECG research studies. The patient is safely isolated from the processing equipment when using the amplifier. This opto-isolated amplifier was also applied industrially for monitoring mercury arc rectifier control signals. The device has proved itself in an industrial environment as an interface for a microprocessor. This unit can be used whenever large offset voltages are found, and can therefore be put to good use in many power electrical engineering applications.

Smith, C. J.

1982-11-01

129

Radio frequency analog electronics based on carbon nanotube transistors  

PubMed Central

The potential to exploit single-walled carbon nanotubes (SWNTs) in advanced electronics represents a continuing, major source of interest in these materials. However, scalable integration of SWNTs into circuits is challenging because of difficulties in controlling the geometries, spatial positions, and electronic properties of individual tubes. We have implemented solutions to some of these challenges to yield radio frequency (RF) SWNT analog electronic devices, such as narrow band amplifiers operating in the VHF frequency band with power gains as high as 14 dB. As a demonstration, we fabricated nanotube transistor radios, in which SWNT devices provide all of the key functions, including resonant antennas, fixed RF amplifiers, RF mixers, and audio amplifiers. These results represent important first steps to practical implementation of SWNTs in high-speed analog circuits. Comparison studies indicate certain performance advantages over silicon and capabilities that complement those in existing compound semiconductor technologies. PMID:18227509

Kocabas, Coskun; Kim, Hoon-sik; Banks, Tony; Rogers, John A.; Pesetski, Aaron A.; Baumgardner, James E.; Krishnaswamy, S. V.; Zhang, Hong

2008-01-01

130

Current gain collapse in microwave multifinger heterojunction bipolar transistors operated at very high power densities  

Microsoft Academic Search

The rapid development of heterojunction bipolar transistor (HBT) technologies has led to the demonstration of high power single-chip microwave amplifiers. Because HBTs are operated at high power densities, the ultimate limits on the performance of HBTs are imposed by thermal considerations. The authors address a thermal phenomenon observed when a multifinger power HBT is operating at high power densities. This

William Liu; Steve Nelson; Darrell G. Hill; Ali Khatibzadeh

1993-01-01

131

Linear-log counting-rate meter uses transconductance characteristics of a silicon planar transistor  

NASA Technical Reports Server (NTRS)

Counting rate meter compresses a wide range of data values, or decades of current. Silicon planar transistor, operating in the zero collector-base voltage mode, is used as a feedback element in an operational amplifier to obtain the log response.

Eichholz, J. J.

1969-01-01

132

High Efficiency Microwave Power Amplifier: From the Lab to Industry  

NASA Technical Reports Server (NTRS)

Since the beginnings of space travel, various microwave power amplifier designs have been employed. These included Class-A, -B, and -C bias arrangements. However, shared limitation of these topologies is the inherent high total consumption of input power associated with the generation of radio frequency (RF)/microwave power. The power amplifier has always been the largest drain for the limited available power on the spacecraft. Typically, the conversion efficiency of a microwave power amplifier is 10 to 20%. For a typical microwave power amplifier of 20 watts, input DC power of at least 100 watts is required. Such a large demand for input power suggests that a better method of RF/microwave power generation is required. The price paid for using a linear amplifier where high linearity is unnecessary includes higher initial and operating costs, lower DC-to-RF conversion efficiency, high power consumption, higher power dissipation and the accompanying need for higher capacity heat removal means, and an amplifier that is more prone to parasitic oscillation. The first use of a higher efficiency mode of power generation was described by Baxandall in 1959. This higher efficiency mode, Class-D, is achieved through distinct switching techniques to reduce the power losses associated with switching, conduction, and gate drive losses of a given transistor.

Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

2001-01-01

133

On 32-GHz cryogenically cooled HEMT low-noise amplifiers  

NASA Technical Reports Server (NTRS)

The cryogenic noise temperature performance of a two-stage and a three-stage 32 GHz High Electron Mobility Transistor (HEMT) amplifier was evaluated. The amplifiers employ 0.25 micrometer conventional AlGaAs/GaAs HEMT devices, hybrid matching input and output microstrip circuits, and a cryogenically stable dc biasing network. The noise temperature measurements were performed in the frequency range of 31 to 33 GHz over a physical temperature range of 300 K down to 12 K. Across the measurement band, the amplifiers displayed a broadband response, and the noise temperature was observed to decrease by a factor of 10 in cooling from 300 K to 15 K. The lowest noise temperature measured for the two-stage amplifier at 32 GHz was 35 K with an associated gain of 16.5 dB, while the three-stage amplifier measured 39 K with an associated gain of 26 dB. It was further observed that both amplifiers were insensitive to light.

Bautista, J. J.; Ortiz, G. G.; Duh, K. H. G.; Kopp, W. F.; Ho, P.; Chao, P. C.; Kao, M. Y.; Smith, P. M.; Ballingall, J. M.

1988-01-01

134

A Matterwave Transistor Oscillator  

E-print Network

A triple-well atomtronic transistor combined with forced RF evaporation is used to realize a driven matterwave oscillator circuit. The transistor is implemented using a metalized compound glass and silicon substrate. On-chip and external currents produce a cigar-shaped magnetic trap, which is divided into transistor source, gate, and drain regions by a pair of blue-detuned optical barriers projected onto the magnetic trap through a chip window. A resonant laser beam illuminating the drain portion of the atomtronic transistor couples atoms emitted by the gate to the vacuum. The circuit operates by loading the source with cold atoms and utilizing forced evaporation as a power supply that produces a positive chemical potential in the source, which subsequently drives oscillation. High-resolution in-trap absorption imagery reveals gate atoms that have tunneled from the source and establishes that the circuit emits a nominally mono-energetic matterwave with a frequency of 23.5(1.0) kHz by tunneling from the gate, ...

Caliga, Seth C; Zozulya, Alex A; Anderson, Dana Z

2012-01-01

135

A Matterwave Transistor Oscillator  

E-print Network

An atomtronic transistor circuit is used to realize a driven matterwave oscillator. The transistor consists of Source and Drain regions separated by a narrow Gate well. Quasi-steady-state behavior is determined from a thermodynamic model, which reveals two oscillation threshold regimes. One is due to the onset of Bose-Einstein condensation in the Gate well, the other is due to the appearance of a negative transresistance regime of the transistor. The thresholds of oscillation are shown to be primarily dependent on the potential energy height difference between Gate-Drain and Gate-Source barriers. The transistor potential is established with a combination of magnetic and optical fields using a compound glass and silicon substrate atom chip. The onset of oscillation and the output matterwave are observed through in-trap imaging. Time-of-flight absorption imaging is used to determine the time dependence of the Source well thermal and chemical energies as well as to estimate the value of the closed-loop ohmic Gate resistance, which is negative and is observed to cause cooling of Source atoms.

Seth C. Caliga; Cameron J. E. Straatsma; Alex A. Zozulya; Dana Z. Anderson

2013-09-13

136

Transistor Fundamentals: The MOSFET  

NSDL National Science Digital Library

Created by Patrick Hoppe of the Wisconsin Online Resource Center this is an introduction to the metal oxide semiconductor field effect transistor (MOSFET). Along with a general introduction, students also examine its enhancement mode. This is a nice brief introduction to the topic.

Hoppe, Patrick

137

Multimode Silicon Nanowire Transistors  

PubMed Central

The combined capabilities of both a nonplanar design and nonconventional carrier injection mechanisms are subject to recent scientific investigations to overcome the limitations of silicon metal oxide semiconductor field effect transistors. In this Letter, we present a multimode field effect transistors device using silicon nanowires that feature an axial n-type/intrinsic doping junction. A heterostructural device design is achieved by employing a self-aligned nickel-silicide source contact. The polymorph operation of the dual-gate device enabling the configuration of one p- and two n-type transistor modes is demonstrated. Not only the type but also the carrier injection mode can be altered by appropriate biasing of the two gate terminals or by inverting the drain bias. With a combined band-to-band and Schottky tunneling mechanism, in p-type mode a subthreshold swing as low as 143 mV/dec and an ON/OFF ratio of up to 104 is found. As the device operates in forward bias, a nonconventional tunneling transistor is realized, enabling an effective suppression of ambipolarity. Depending on the drain bias, two different n-type modes are distinguishable. The carrier injection is dominated by thermionic emission in forward bias with a maximum ON/OFF ratio of up to 107 whereas in reverse bias a Schottky tunneling mechanism dominates the carrier transport. PMID:25303290

2014-01-01

138

Radiation-hardened transistor and integrated circuit  

DOEpatents

A composite transistor is disclosed for use in radiation hardening a CMOS IC formed on an SOI or bulk semiconductor substrate. The composite transistor has a circuit transistor and a blocking transistor connected in series with a common gate connection. A body terminal of the blocking transistor is connected only to a source terminal thereof, and to no other connection point. The blocking transistor acts to prevent a single-event transient (SET) occurring in the circuit transistor from being coupled outside the composite transistor. Similarly, when a SET occurs in the blocking transistor, the circuit transistor prevents the SET from being coupled outside the composite transistor. N-type and P-type composite transistors can be used for each and every transistor in the CMOS IC to radiation harden the IC, and can be used to form inverters and transmission gates which are the building blocks of CMOS ICs.

Ma, Kwok K. (Albuquerque, NM)

2007-11-20

139

Amplified DNA Biosensors  

Microsoft Academic Search

\\u000a Amplified detection of DNA is a central research topic in modern bioanalytical science. Electronic or optical transduction\\u000a of DNA recognition events provides readout signals for DNA biosensors. Amplification of the DNA analysis is accomplished by\\u000a the coupling of nucleic acid-functionalized enzymes or nucleic acid-functionalized nanoparticles (NP) as labels for the DNA\\u000a duplex formation. This chapter discusses the amplified amperometric analysis

Itamar Willner; Bella Shlyahovsky; Bilha Willner; Maya Zayats

2009-01-01

140

Raman amplifiers for telecommunications  

Microsoft Academic Search

Raman amplifiers are being deployed in almost every new long-haul and ultralong-haul fiber-optic transmission systems, making them one of the first widely commercialized nonlinear optical devices in telecommunications. This paper reviews some of the technical reasons behind the wide-spread acceptance of Raman technology. Distributed Raman amplifiers improve the noise figure and reduce the nonlinear penalty of fiber systems, allowing for

Mohammed N. Islam

2002-01-01

141

A grid amplifier  

Microsoft Academic Search

A 50-MESFET grid amplifier is reported that has a gain of 11 dB at 3.3 GHz. The grid isolates the input from the output by using vertical polarization for the input beam and horizontal polarization for the transmitted output beam. The grid unit cell is a two-MESFET differential amplifier. A simple calibration procedure allows the gain to be calculated from

M. Kim; J. J. Rosenberg; R. P. Smith; J. B. Hacker; M. P. DeLisio; D. B. Rutledge

1991-01-01

142

Organic Semiconductor Optical Amplifiers  

Microsoft Academic Search

Organic semiconducting materials have been researched for novel optoelectronic devices due to their efficient light emission and high gain properties. Such devices range from organic light-emitting diodes and solar cells to lasers and amplifiers. This paper explores the research carried out on one of these devices: organic semiconductor amplifiers that have shown to give high gains of 20-40 dB in

Dimali Amarasinghe; Arvydas Ruseckas; Graham A. Turnbull; Ifor D. W. Samuel

2009-01-01

143

NASA satellite communications application research, phase 2 addendum. Efficient high power, solid state amplifier for EHF communications  

NASA Technical Reports Server (NTRS)

This document is an addendum to the NASA Satellite Communications Application Research (SCAR) Phase 2 Final Report, 'Efficient High Power, Solid State Amplifier for EHF Communications.' This report describes the work performed from 1 August 1993 to 11 March 1994, under contract number NASW-4513. During this reporting period an array of transistor amplifiers was repaired by replacing all MMIC amplifier chips. The amplifier array was then tested using three different feedhorn configurations. Descriptions, procedures, and results of this testing are presented in this report, and conclusions are drawn based on the test results obtained.

Benet, James

1994-01-01

144

EE 321 Amplifiers Fall 2008 Amplifiers, Biasing, and AC Coupling  

E-print Network

EE 321 Amplifiers Fall 2008 EE321 Lab Amplifiers, Biasing, and AC Coupling The purpose of this lab is to measure the characteristics of an amplifier, and to use the characteristics to add a bias circuit at the input. An amplifier can be represented in many different ways. Figure 1 shows a model for a voltage

Wedeward, Kevin

145

Dynamic properties of power MOS transistors  

NASA Astrophysics Data System (ADS)

Power MOSFET's were modeled in dynamic high frequency and switching regimes, based on a theoretical analysis of the active region, taking into account the short channel effects and those related to structural configuration elements. The theoretical synthesis of intrinsic and parasitic elements leads to a complete nonlinear physical model compatible with electric simulators. The model is used for simulation and computer aided design of electric circuits which use power MOSFET's such as RF amplifiers, and frequency doublers. For the switching regime, a hierarchy of models for power V.DMOS transistors is developed. Two compact models consistent with SPICE-2 program and well suited for study and characterization of power V.DMOSFET, in switching condition under resistive and inductive loads, are proposed. They can describe low, medium, and high voltage structures.

Belabadia, Mohammed

146

Measuring bi-directional current through a field-effect transistor by virtue of drain-to-source voltage measurement  

DOEpatents

A method and apparatus for measuring current, and particularly bi-directional current, in a field-effect transistor (FET) using drain-to-source voltage measurements. The drain-to-source voltage of the FET is measured and amplified. This signal is then compensated for variations in the temperature of the FET, which affects the impedance of the FET when it is switched on. The output is a signal representative of the direction of the flow of current through the field-effect transistor and the level of the current through the field-effect transistor. Preferably, the measurement only occurs when the FET is switched on.

Turner, Steven Richard

2006-12-26

147

Submillimeter-Wave Amplifier Module with Integrated Waveguide Transitions  

NASA Technical Reports Server (NTRS)

To increase the usefulness of monolithic millimeter-wave integrated circuit (MMIC) components at submillimeter-wave frequencies, a chip has been designed that incorporates two integrated, radial E-plane probes with an MMIC amplifier in between, thus creating a fully integrated waveguide module. The integrated amplifier chip has been fabricated in 35-nm gate length InP high-electron-mobility-transistor (HEMT) technology. The radial probes were mated to grounded coplanar waveguide input and output lines in the internal amplifier. The total length of the internal HEMT amplifier is 550 m, while the total integrated chip length is 1,085 m. The chip thickness is 50 m with the chip width being 320 m. The internal MMIC amplifier is biased through wire-bond connections to the gates and drains of the chip. The chip has 3 stages, employing 35-nm gate length transistors in each stage. Wire bonds from the DC drain and gate pads are connected to off-chip shunt 51-pF capacitors, and additional off-chip capacitors and resistors are added to the gate and drain bias lines for low-frequency stability of the amplifier. Additionally, bond wires to the grounded coplanar waveguide pads at the RF input and output of the internal amplifier are added to ensure good ground connections to the waveguide package. The S-parameters of the module, not corrected for input or output waveguide loss, are measured at the waveguide flange edges. The amplifier module has over 10 dB of gain from 290 to 330 GHz, with a peak gain of over 14 dB at 307 GHz. The WR2.2 waveguide cutoff is again observed at 268 GHz. The module is biased at a drain current of 27 mA, a drain voltage of 1.24 V, and a gate voltage of +0.21 V. Return loss of the module is very good between 5 to 25 dB. This result illustrates the usefulness of the integrated radial probe transition, and the wide (over 10-percent) bandwidth that one can expect for amplifier modules with integrated radial probes in the submillimeter-regime (>300 GHz).

Samoska, Lorene; Chattopadhyay, Goutam; Pukala, David; Gaier, Todd; Soria, Mary; ManFung, King; Deal, William; Mei, Gerry; Radisic, Vesna; Lai, Richard

2009-01-01

148

Improved chopper circuit uses parallel transistors  

NASA Technical Reports Server (NTRS)

Parallel transistor chopper circuit operates with one transistor in the forward mode and the other in the inverse mode. By using this method, it acts as a single, symmetrical, bidirectional transistor, and reduces and stabilizes the offset voltage.

1966-01-01

149

Electrospun amplified fiber optics.  

PubMed

All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ?20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics. PMID:25710188

Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

2015-03-11

150

Electrospun Amplified Fiber Optics  

PubMed Central

All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ?20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm–1). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics. PMID:25710188

2015-01-01

151

Bipolar Junction Transistors  

NSDL National Science Digital Library

All About Circuits is a website that â??provides a series of online textbooks covering electricity and electronics.â? Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Bipolar Junction Transistors, is the fourth chapter in Volume III â??Semiconductors. A few of the topics covered in this chapter include: The Transistor as a Switch, Active Mode Operation, and Input and Output Coupling. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

152

A C-band GaN based linear power amplifier with 55.7% PAE  

NASA Astrophysics Data System (ADS)

A C-band linear power amplifier is successfully developed with a one-chip 2 mm AlGaN/GaN high electron mobility transistors (HEMTs). Two kinds of matching circuits for the linear power amplifier are compared. Besides, stabilization methods for the amplifier are also discussed. At 5.4 GHz, the developed GaN HEMTs linear power amplifier delivers a 37.2 dBm (5.2 W) cw P1 dB output power with 9 dB linear gain and 55.7% maximum power-added efficiency (PAE) with a drain voltage of 25 V. To our best knowledge, the achieved PAE is the state-of-the-art result ever reported for 2 mm gate width single die GaN-based hybrid microwave integrated power amplifier at C-band.

Luo, Weijun; Chen, Xiaojuan; Zhang, Hui; Liu, Guoguo; Zheng, Yingkui; Liu, Xinyu

2010-04-01

153

The microtubule transistor  

E-print Network

I point out the similarity between the microtubule experiment reported by Priel et al [Biophys. J. 90, 4639 (2006)] and the ZnO nanowire experiment of Wang et al [Nanolett. 6, 2768 (2006)]. It is quite possible that MTs are similar to a piezoelectric field effect transistor for which the role of the control gate electrode is played by the piezo-induced electric field across the width of the MT walls and their elastic bending features

H. C. Rosu

2007-03-26

154

A grid amplifier  

NASA Technical Reports Server (NTRS)

A 50-MESFET grid amplifier is reported that has a gain of 11 dB at 3.3 GHz. The grid isolates the input from the output by using vertical polarization for the input beam and horizontal polarization for the transmitted output beam. The grid unit cell is a two-MESFET differential amplifier. A simple calibration procedure allows the gain to be calculated from a relative power measurement. This grid is a hybrid circuit, but the structure is suitable for fabrication as a monolithic wafer-scale integrated circuit, particularly at millimeter wavelengths.

Kim, Moonil; Weikle, Robert M., II; Hacker, Jonathan B.; Delisio, Michael P.; Rutledge, David B.; Rosenberg, James J.; Smith, R. P.

1991-01-01

155

Universal signal conditioning amplifier  

NASA Technical Reports Server (NTRS)

Engineers at NASA's Kennedy Space Center have designed a signal conditioning amplifier which automatically matches itself to almost any kind of transducer. The product, called Universal Signal Conditioning Amplifier (USCA), uses state-of-the-art technologies to deliver high accuracy measurements. USCA's features which can be either programmable or automated include: voltage, current, or pulsed excitation, unlimited resolution gain, digital filtering and both analog and digital output. USCA will be used at Kennedy Space Center's launch pads for environmental measurements such as vibrations, strains, temperatures and overpressures. USCA is presently being commercialized through a co-funded agreement between NASA, the State of Florida, and Loral Test and Information Systems, Inc.

Larson, William E.; Hallberg, Carl; Medelius, Pedro J.

1994-01-01

156

A Bio-Polymer Transistor: Electrical Amplification by Microtubules  

E-print Network

Microtubules (MTs) are important cytoskeletal structures, engaged in a number of specific cellular activities, including vesicular traffic, cell cyto-architecture and motility, cell division, and information processing within neuronal processes. MTs have also been implicated in higher neuronal functions, including memory, and the emergence of "consciousness". How MTs handle and process electrical information, however, is heretofore unknown. Here we show new electrodynamic properties of MTs. Isolated, taxol-stabilized microtubules behave as bio-molecular transistors capable of amplifying electrical information. Electrical amplification by MTs can lead to the enhancement of dynamic information, and processivity in neurons can be conceptualized as an "ionic-based" transistor, which may impact among other known functions, neuronal computational capabilities.

Avner Priel; Arnolt J. Ramos; Jack A. Tuszynski; Horacio F. Cantiello

2006-06-09

157

Fourier plane image amplifier  

DOEpatents

A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

1995-12-12

158

Fourier plane image amplifier  

DOEpatents

A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

Hackel, Lloyd A. (Livermore, CA); Hermann, Mark R. (San Ramon, CA); Dane, C. Brent (Livermore, CA); Tiszauer, Detlev H. (Tracy, CA)

1995-01-01

159

How Semiconductors and Transistors Work  

NSDL National Science Digital Library

This NSF funded site, at the University of Virginia, shows how semiconductors and transistors are constructed and work. This is a Virtual Science Lab that lets the users see how semiconductor crystals work and how they are used to make transistor switches. It is presented as a Powerpoint presentation and employs flash animation to convey many of the points.

Bean, John C.

160

A multiple-input operational transconductance amplifier with a wide linear range  

E-print Network

Ramirez ? Angulo, Dr. Norman Griswold, and Dr. Wiley Kirk for their time and comments. l would also like to thank Dr. Richard Newton for sitting in on the oral presentation. TABLE OF CONTENTS CHAPTER Page I INTRODUCTION A. Organization II OPERATION... diagrams Transistors gl and Q2 form a differential amplifier which is biased by Dl and Q3. Transistors Q4 ? Qll function as current mirrors to form the output current I, = I, q ? I, t. (This assumes a unity current gain in the mirrors. ) Currents I...

Reed, Russell Deryl

1986-01-01

161

Cryogenically Cooled Field Effect Transistors for Low-Noise Systems  

NASA Technical Reports Server (NTRS)

Recent tends in the design, fabrication and use of High-Electron-Mobility-Transistors (HEMT) in low noise amplifiers are reviewed. Systems employing these devices have achieved the lowest system noise for wavelengths greater than three millimeters with relatively modest cryogenic cooling requirements in a variety of ground and space based applications. System requirements which arise in employing such devices in imaging applications are contrasted with other leading coherent detector candidates at microwave wavelengths. Fundamental and practical limitations which arise in the context of microwave application of field effect devices at cryogenic temperatures will be discussed from a component and systems point of view.

Wollack, Edward J.

2002-01-01

162

Cryogenetically Cooled Field Effect Transistors for Low-Noise Systems  

NASA Technical Reports Server (NTRS)

Recent tends in the design, fabrication and use of High-Electron-Mobility-Transistors (HEMT) in low noise amplifiers are reviewed. Systems employing these devices have achieved the lowest system noise for wavelengths greater than three millimeters with relatively modest cryogenic cooling requirements in a variety of ground and space based applications. System requirements which arise in employing such devices in imaging applications are contrasted with other leading coherent detector candidates at microwave wavelengths. Fundamental and practical limitations which arise in the context of microwave application of field effect devices at cryogenic temperatures will be discussed from a component and systems point of view.

Wollack, Edward J.; Rabin, Douglas M. (Technical Monitor)

2002-01-01

163

A photonic transistor device based on photons and phonons in a cavity electromechanical system  

E-print Network

We present a scheme for photonic transistors based on photons and phonons in a cavity electromechanical system, which is consisted of a superconducting microwave cavity coupled to a nanomechanical resonator. Control of the propagation of photons is achieved through the interaction of microwave field (photons) and nanomechanical vibrations (phonons). By calculating the transmission spectrum of the signal field, we show that the signal field can be efficiently attenuated or amplified, depending on the power of a second `gating'(pump) field. This scheme may be a promising candidate for single-photon transistors and pave the way for numerous applications in telecommunication and quantum information technologies.

Jiang, Cheng

2012-01-01

164

A photonic transistor device based on photons and phonons in a cavity electromechanical system  

E-print Network

We present a scheme for photonic transistors based on photons and phonons in a cavity electromechanical system, which is consisted of a superconducting microwave cavity coupled to a nanomechanical resonator. Control of the propagation of photons is achieved through the interaction of microwave field (photons) and nanomechanical vibrations (phonons). By calculating the transmission spectrum of the signal field, we show that the signal field can be efficiently attenuated or amplified, depending on the power of a second `gating'(pump) field. This scheme may be a promising candidate for single-photon transistors and pave the way for numerous applications in telecommunication and quantum information technologies.

Cheng Jiang; Ka-Di Zhu

2012-09-21

165

The coupled atom transistor  

NASA Astrophysics Data System (ADS)

We describe the first implementation of a coupled atom transistor where two shallow donors (P or As) are implanted in a nanoscale silicon nanowire and their electronic levels are controlled with three gate voltages. Transport spectroscopy through these donors placed in series is performed both at zero and microwave frequencies. The coherence of the charge transfer between the two donors is probed by Landau–Zener–Stückelberg interferometry. Single-charge transfer at zero bias (electron pumping) has been performed and the crossover between the adiabatic and non-adiabatic regimes is studied.

Jehl, X.; Voisin, B.; Roche, B.; Dupont-Ferrier, E.; De Franceschi, S.; Sanquer, M.; Cobian, M.; Niquet, Y.-M.; Sklénard, B.; Cueto, O.; Wacquez, R.; Vinet, M.

2015-04-01

166

From transistor to nanotube  

NASA Astrophysics Data System (ADS)

We present here the main steps in the evolution of the transistor, since the tremendous invention of such a device and the introduction of the integrated circuit. We will then recall the main steps of Moore's law development. Nanotechnology began at the very beginning of the 21st century. Two aspects are presented in this article: the first, called 'More Moore', consists in continuing the laws of scale up to the physical limits; the second aspect, called 'beyond CMOS' explores new concepts such as spintronics, moletronics, nanotronics and other types of molecular electronics. To cite this article: J.-C. Boudenot, C. R. Physique 9 (2008).

Boudenot, Jean-Claude

2008-01-01

167

The coupled atom transistor.  

PubMed

We describe the first implementation of a coupled atom transistor where two shallow donors (P or As) are implanted in a nanoscale silicon nanowire and their electronic levels are controlled with three gate voltages. Transport spectroscopy through these donors placed in series is performed both at zero and microwave frequencies. The coherence of the charge transfer between the two donors is probed by Landau-Zener-Stückelberg interferometry. Single-charge transfer at zero bias (electron pumping) has been performed and the crossover between the adiabatic and non-adiabatic regimes is studied. PMID:25783566

Jehl, X; Voisin, B; Roche, B; Dupont-Ferrier, E; De Franceschi, S; Sanquer, M; Cobian, M; Niquet, Y-M; Sklénard, B; Cueto, O; Wacquez, R; Vinet, M

2015-04-22

168

Power transistor switching characterization  

NASA Technical Reports Server (NTRS)

The switching properties of power transistors are investigated. The devices studied were housed in IO-3 cases and were of an n(+)-p-n(-)-n(+) vertical dopant structure. The effects of the magnitude of the reverse-base current and temperature on the reverse-bias second breakdown characteristics are discussed. Brief discussions of device degradation due to second breakdown and of a constant voltage turn-off circuit are included. A description of a vacuum tube voltage clamp circuit which reduces clamped collector voltage overshoot is given.

Blackburn, D. L.

1981-01-01

169

Carbon Nanotubes as Schottky Barrier Transistors  

Microsoft Academic Search

We show that carbon nanotube transistors operate as unconventional ``Schottky barrier transistors,'' in which transistor action occurs primarily by varying the contact resistance rather than the channel conductance. Transistor characteristics are calculated for both idealized and realistic geometries, and scaling behavior is demonstrated. Our results explain a variety of experimental observations, including the quite different effects of doping and adsorbed

S. Heinze; J. Tersoff; R. Martel; V. Derycke; J. Appenzeller; Ph. Avouris

2002-01-01

170

RICE UNIVERSITY Transport in Single Molecule Transistors  

E-print Network

RICE UNIVERSITY Transport in Single Molecule Transistors by Lam H. Yu A Thesis Submitted in Partial Houston, Texas January, 2006 #12;Abstract Transport in Single Molecule Transistors by Lam H. Yu molecule transistors (SMTs), nanometer-scale transistors in which charge transport occurs through

Natelson, Douglas

171

Differential Amplifier for use with  

E-print Network

Differential Amplifier for use with Attenuated Probes Clint Sprott December 17, 1964 University of Wisconsin Thermonuclear Plasma Studies PLP 43 Copy No. 3, #12;Introduction: Differential Amplifier for use a factor of ten. Using the probe shown in Fig. 1 and the cathode follower amplifier circuit shown in Fig. 3

Sprott, Julien Clinton

172

Input impedance and gain of a gigahertz amplifier using a dc superconducting quantum interference device in a quarter wave resonator  

Microsoft Academic Search

Due to their superior noise performance, superconducting quantum interference devices (SQUIDs) are an attractive alternative to high electron mobility transistors for constructing ultra-low-noise microwave amplifiers for cryogenic use. We describe the use of a lumped element SQUID inductively coupled to a quarter wave resonator. The resonator acts as an impedance transformer and also makes it possible to accurately measure the

Lafe Spietz; Kent Irwin; José Aumentado

2008-01-01

173

Monolithic dye laser amplifier  

DOEpatents

A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Kuklo, T.C.

1993-03-30

174

Monolithic dye laser amplifier  

DOEpatents

A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Kuklo, Thomas C. (Ripon, CA)

1993-01-01

175

Helical Fiber Amplifier  

DOEpatents

A multi-mode gain fiber is provided which affords substantial improvements in the maximum pulse energy, peak power handling capabilities, average output power, and/or pumping efficiency of fiber amplifier and laser sources while maintaining good beam quality (comparable to that of a conventional single-mode fiber source). These benefits are realized by coiling the multimode gain fiber to induce significant bend loss for all but the lowest-order mode(s).

Koplow, Jeffrey P. (Washington, DC); Kliner, Dahy (San Ramon, CA); Goldberg, Lew (Fairfax, VA)

2002-12-17

176

Flexible and low-voltage integrated circuits constructed from high-performance nanocrystal transistors.  

PubMed

Colloidal semiconductor nanocrystals are emerging as a new class of solution-processable materials for low-cost, flexible, thin-film electronics. Although these colloidal inks have been shown to form single, thin-film field-effect transistors with impressive characteristics, the use of multiple high-performance nanocrystal field-effect transistors in large-area integrated circuits has not been shown. This is needed to understand and demonstrate the applicability of these discrete nanocrystal field-effect transistors for advanced electronic technologies. Here we report solution-deposited nanocrystal integrated circuits, showing nanocrystal integrated circuit inverters, amplifiers and ring oscillators, constructed from high-performance, low-voltage, low-hysteresis CdSe nanocrystal field-effect transistors with electron mobilities of up to 22 cm(2) V(-1) s(-1), current modulation >10(6) and subthreshold swing of 0.28 V dec(-1). We fabricated the nanocrystal field-effect transistors and nanocrystal integrated circuits from colloidal inks on flexible plastic substrates and scaled the devices to operate at low voltages. We demonstrate that colloidal nanocrystal field-effect transistors can be used as building blocks to construct complex integrated circuits, promising a viable material for low-cost, flexible, large-area electronics. PMID:23169057

Kim, David K; Lai, Yuming; Diroll, Benjamin T; Murray, Christopher B; Kagan, Cherie R

2012-01-01

177

A high voltage UMOS transistor  

NASA Astrophysics Data System (ADS)

A throretical and experimental study of a novel UMOS (U for U-shaped notch) transistor structure is presented. This short channel device combines a simple U-groove geometry with features similar to those of DMOS transistors. Voltage and switching capabilities are investigated. Necessary trade-offs are emphasized in the design process and the critical fabrication steps are discussed. Both the theoretical considerations as well as the experimental results indicate that the UMOS transistor described is suitable for high voltage switching applications.

Tarasewicz, S.; Salama, C. A. T.

1981-05-01

178

High voltage electrical amplifier having a short rise time  

DOEpatents

A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)

1991-01-01

179

A New Microwave High Power Transistor (Static Induction Transistor)  

Microsoft Academic Search

A high power transistor at microwave frequency has been realized by multi-chips of static induction transistor. An output power of 100 W at 1 GHz was obtained by good design of thermal balance and improvement of packaging. A gain of 2.2 dB and a drain efficiency of 42 % was obtained at output power of 100 W. The linear gain

Y. Kajiwara; K. Horikiri; Y. Yukimoto

1978-01-01

180

Adiabatic Quantum Transistors  

DOE PAGESBeta

We describe a many-body quantum system that can be made to quantum compute by the adiabatic application of a large applied field to the system. Prior to the application of the field, quantum information is localized on one boundary of the device, and after the application of the field, this information propagates to the other side of the device, with a quantum circuit applied to the information. The applied circuit depends on the many-body Hamiltonian of the material, and the computation takes place in a degenerate ground space with symmetry-protected topological order. Such “adiabatic quantum transistors” are universal adiabatic quantum computing devices that have the added benefit of being modular. Here, we describe this model, provide arguments for why it is an efficient model of quantum computing, and examine these many-body systems in the presence of a noisy environment.

Bacon, Dave; Flammia, Steven T.; Crosswhite, Gregory M.

2013-06-01

181

High transconductance organic electrochemical transistors  

PubMed Central

The development of transistors with high gain is essential for applications ranging from switching elements and drivers to transducers for chemical and biological sensing. Organic transistors have become well-established based on their distinct advantages, including ease of fabrication, synthetic freedom for chemical functionalization, and the ability to take on unique form factors. These devices, however, are largely viewed as belonging to the low-end of the performance spectrum. Here we present organic electrochemical transistors with a transconductance in the mS range, outperforming transistors from both traditional and emerging semiconductors. The transconductance of these devices remains fairly constant from DC up to a frequency of the order of 1?kHz, a value determined by the process of ion transport between the electrolyte and the channel. These devices, which continue to work even after being crumpled, are predicted to be highly relevant as transducers in biosensing applications. PMID:23851620

Khodagholy, Dion; Rivnay, Jonathan; Sessolo, Michele; Gurfinkel, Moshe; Leleux, Pierre; Jimison, Leslie H.; Stavrinidou, Eleni; Herve, Thierry; Sanaur, Sébastien; Owens, Róisín M.; Malliaras, George G.

2013-01-01

182

Transistor sizing in CMOS circuits  

Microsoft Academic Search

The problem of optimally sizing transistors in a VLSI CMOS circuit is considered. Models and algorithms for performing optimization on a single path using RC-tree approximation are presented. The results of an automatic optimization procedure are discussed.

Mehmet A. Cirit

1987-01-01

183

The Use of a Solid State Analog Television Transmitter as a Superconducting Electron Gun Power Amplifier  

SciTech Connect

A solid state analog television transmitter designed for 200 MHz operation is being commissioned as a radio frequency power amplifier on the Wisconsin superconducting electron gun cavity. The amplifier consists of three separate radio frequency power combiner cabinets and one monitor and control cabinet. The transmitter employs rugged field effect transistors built into one kilowatt drawers that are individually hot swappable at maximum continuous power output. The total combined power of the transmitter system is 33 kW at 200 MHz, output through a standard coaxial transmission line. A low level radio frequency system is employed to digitally synthesize the 200 MHz signal and precisely control amplitude and phase.

J.G. Kulpin, K.J. Kleman, R.A. Legg

2012-07-01

184

AIDA: A 16-channel amplifier ASIC to read out the advanced implantation detector array for experiments in nuclear decay spectroscopy  

SciTech Connect

We have designed a read-out ASIC for nuclear decay spectroscopy as part of the AIDA project - the Advanced Implantation Detector Array. AIDA will be installed in experiments at the Facility for Antiproton and Ion Research in GSI, Darmstadt. The AIDA ASIC will measure the signals when unstable nuclei are implanted into the detector, followed by the much smaller signals when the nuclei subsequently decay. Implant energies can be as high as 20 GeV; decay products need to be measured down to 25 keV within just a few microseconds of the initial implants. The ASIC uses two amplifiers per detector channel, one covering the 20 GeV dynamic range, the other selectable over a 20 MeV or 1 GeV range. The amplifiers are linked together by bypass transistors which are normally switched off. The arrival of a large signal causes saturation of the low-energy amplifier and a fluctuation of the input voltage, which activates the link to the high-energy amplifier. The bypass transistors switch on and the input charge is integrated by the high-energy amplifier. The signal is shaped and stored by a peak-hold, then read out on a multiplexed output. Control logic resets the amplifiers and bypass circuit, allowing the low-energy amplifier to measure the subsequent decay signal. We present simulations and test results, demonstrating the AIDA ASIC operation over a wide range of input signals. (authors)

Braga, D. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom); Coleman-Smith, P. J. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Davinson, T. [Dept. of Physics and Astronomy, Univ. of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Lazarus, I. H. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Page, R. D. [Dept. of Physics, Univ. of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE (United Kingdom); Thomas, S. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom)

2011-07-01

185

High-Power, High-Frequency Si-Based (SiGe) Transistors Developed  

NASA Technical Reports Server (NTRS)

Future NASA, DOD, and commercial products will require electronic circuits that have greater functionality and versatility but occupy less space and cost less money to build and integrate than current products. System on a Chip (SOAC), a single semiconductor substrate containing circuits that perform many functions or containing an entire system, is widely recognized as the best technology for achieving low-cost, small-sized systems. Thus, a circuit technology is required that can gather, process, store, and transmit data or communications. Since silicon-integrated circuits are already used for data processing and storage and the infrastructure that supports silicon circuit fabrication is very large, it is sensible to develop communication circuits on silicon so that all the system functions can be integrated onto a single wafer. Until recently, silicon integrated circuits did not function well at the frequencies required for wireless or microwave communications, but with the introduction of small amounts of germanium into the silicon to make silicon-germanium (SiGe) transistors, silicon-based communication circuits are possible. Although microwavefrequency SiGe circuits have been demonstrated, there has been difficulty in obtaining the high power from their transistors that is required for the amplifiers of a transmitter, and many researchers have thought that this could not be done. The NASA Glenn Research Center and collaborators at the University of Michigan have developed SiGe transistors and amplifiers with state-of-the-art output power at microwave frequencies from 8 to 20 GHz. These transistors are fabricated using standard silicon processing and may be integrated with CMOS integrated circuits on a single chip. A scanning electron microscope image of a typical SiGe heterojunction bipolar transistor is shown in the preceding photomicrograph. This transistor achieved a record output power of 550 mW and an associated power-added efficiency of 33 percent at 8.4 GHz, as shown. Record performance was also demonstrated at 12.6 and 18 GHz. Developers have combined these state-of-the-art transistors with transmission lines and micromachined passive circuit components, such as inductors and capacitors, to build multistage amplifiers. Currently, a 1-W, 8.4-GHz power amplifier is being built for NASA deep space communication architectures.

Ponchak, George E.

2002-01-01

186

Amplifying Electrochemical Indicators  

NASA Technical Reports Server (NTRS)

Dendrimeric reporter compounds have been invented for use in sensing and amplifying electrochemical signals from molecular recognition events that involve many chemical and biological entities. These reporter compounds can be formulated to target specific molecules or molecular recognition events. They can also be formulated to be, variously, hydrophilic or amphiphilic so that they are suitable for use at interfaces between (1) aqueous solutions and (2) electrodes connected to external signal-processing electronic circuits. The invention of these reporter compounds is expected to enable the development of highly miniaturized, low-power-consumption, relatively inexpensive, mass-producible sensor units for diverse applications.

Fan, Wenhong; Li, Jun; Han, Jie

2004-01-01

187

Few-layer molybdenum disulfide transistors and circuits for high-speed flexible electronics  

PubMed Central

Two-dimensional layered materials, such as molybdenum disulfide, are emerging as an exciting material system for future electronics due to their unique electronic properties and atomically thin geometry. Here we report a systematic investigation of MoS2 transistors with optimized contact and device geometry, to achieve self-aligned devices with performance including an intrinsic gain over 30, an intrinsic cut-off frequency fT up to 42 GHz and a maximum oscillation frequency fMAX up to 50 GHz, exceeding the reported values for MoS2 transistors to date (fT ~ 0.9 GHz, fMAX ~ 1 GHz). Our results show that logic inverters or radio frequency amplifiers can be formed by integrating multiple MoS2 transistors on quartz or flexible substrates with voltage gain in the gigahertz regime. This study demonstrates the potential of two-dimensional layered semiconductors for high-speed flexible electronics. PMID:25295573

Cheng, Rui; Jiang, Shan; Chen, Yu; Liu, Yuan; Weiss, Nathan; Cheng, Hung-Chieh; Wu, Hao; Huang, Yu; Duan, Xiangfeng

2014-01-01

188

Few-layer molybdenum disulfide transistors and circuits for high-speed flexible electronics  

NASA Astrophysics Data System (ADS)

Two-dimensional layered materials, such as molybdenum disulfide, are emerging as an exciting material system for future electronics due to their unique electronic properties and atomically thin geometry. Here we report a systematic investigation of MoS2 transistors with optimized contact and device geometry, to achieve self-aligned devices with performance including an intrinsic gain over 30, an intrinsic cut-off frequency fT up to 42?GHz and a maximum oscillation frequency fMAX up to 50?GHz, exceeding the reported values for MoS2 transistors to date (fT~0.9?GHz, fMAX~1?GHz). Our results show that logic inverters or radio frequency amplifiers can be formed by integrating multiple MoS2 transistors on quartz or flexible substrates with voltage gain in the gigahertz regime. This study demonstrates the potential of two-dimensional layered semiconductors for high-speed flexible electronics.

Cheng, Rui; Jiang, Shan; Chen, Yu; Liu, Yuan; Weiss, Nathan; Cheng, Hung-Chieh; Wu, Hao; Huang, Yu; Duan, Xiangfeng

2014-10-01

189

Medium power amplifiers covering 90 - 130 GHz for telescope local oscillators  

NASA Technical Reports Server (NTRS)

This paper describes a set of power amplifier (PA) modules containing InP High Electron Mobility Transistor (HEMT) Monolithic Millimeter-wave Integrated Circuit (MMIC) chips. The chips were designed and optimized for local oscillator sources in the 90-130 GHz band for the Atacama Large Millimeter Array telescope. The modules feature 20-45 mW of output power, to date the highest power from solid state HEMT MMIC modules above 110 GHz.

Samoska, Lorene A.; Bryerton, Eric; Pukala, David; Peralta, Alejandro; Hu, Ming; Schmitz, Adele

2005-01-01

190

High Power Wideband AlGaN\\/GaN HEMT Feedback Amplifier Module  

Microsoft Academic Search

A high power wideband feedback amplifier module using AlGaN\\/GaN high electron mobility transistor (HEMT) has been developed that covers the frequency range of DC to 5 GHz with small signal gain of 9 dB. Shunt feedback topology is employed by adding inductive components to increase the bandwidth. At midband frequency, power added efficiency (PAE) of 20 % and saturation power

Y. Chung; S. Cai; W. Lee; Y. Lin; C. P. Wen; K. L. Wang; T. Itoh

1980-01-01

191

A new optoelectronic integrated device for light-amplifying optical switch (LAOS)  

Microsoft Academic Search

A new optoelectronic integrated device is proposed for a light-amplifying optical switch (LAOS). The device is composed of an optical field-effect transistor (OPFET) in series with a light source which may be either a double heterostructure light-emitting diode (LED) or laser diode (LD). A quantitative circuit model for the proposed LAOS is presented and theoretical investigation is carried out for

Satyabrata Jit; B. B. Pal

2001-01-01

192

A rail-to-rail constant-gm low-voltage CMOS operational transconductance amplifier  

Microsoft Academic Search

A new operational transconductance amplifier working with supply voltages down to 1.3 V has been realized in a standard 0.7-?m CMOS technology. A constant transconductance (within 6% of maximum variation) is ensured for the whole common-mode input range. The input transistors operate in weak inversion. The class AB output stage also has a full voltage swing. The circuit provides a

Giuseppe Ferri; Willy Sansen

1997-01-01

193

Operational amplifier with 1-V rail-to-rail multipath-driven output stage  

Microsoft Academic Search

A bipolar operational amplifier (op amp) with a rail-to-rail multipath-driven output stage that operates at supply voltages down to 1 V is presented. The bandwidth of this output stage is as high as possible, viz, equal to that of one of the output transistors, loaded by the output capacitance. The output voltage can reach both supply rails within 100 mV

Jeroen Fonderie; Johan H. Huijsing

1991-01-01

194

Effects of output low impedance termination to linearity of GaAs HBT power amplifier  

Microsoft Academic Search

Improving linearity over a broad band is a major goal in RF design. This paper demonstrates that adding a low impedance termination at the envelope frequency (?2-?1) to the output of a Gallium Arsenide (GaAs) Heterojunction Bipolar Transistor (HBT) Distributed Amplifier (DA) improves the third order output intercept point (OIP3) over a bandwidth of 2.5 GHz to 3 GHz by

Koh Minghao; Grant A. Ellis; Teoh Chin Soon

2010-01-01

195

Evolvable circuit with transistor-level reconfigurability  

NASA Technical Reports Server (NTRS)

An evolvable circuit includes a plurality of reconfigurable switches, a plurality of transistors within a region of the circuit, the plurality of transistors having terminals, the plurality of transistors being coupled between a power source terminal and a power sink terminal so as to be capable of admitting power between the power source terminal and the power sink terminal, the plurality of transistors being coupled so that every transistor terminal to transistor terminal coupling within the region of the circuit comprises a reconfigurable switch.

Stoica, Adrian (Inventor); Salazar-Lazaro, Carlos Harold (Inventor)

2004-01-01

196

DIAMOND AMPLIFIED PHOTOCATHODES.  

SciTech Connect

High-average-current linear electron accelerators require photoinjectors capable of delivering tens to hundreds of mA average current, with peak currents of hundreds of amps. Standard photocathodes face significant challenges in meeting these requirements, and often have short operational lifetimes in an accelerator environment. We report on recent progress toward development of secondary emission amplifiers for photocathodes, which are intended to increase the achievable average current while protecting the cathode from the accelerator. The amplifier is a thin diamond wafer which converts energetic (few keV) primary electrons into hundreds of electron-hole pairs via secondary electron emission. The electrons drift through the diamond under an external bias and are emitted into vacuum via a hydrogen-terminated surface with negative electron affinity (NEA). Secondary emission gain of over 200 has been achieved. Two methods of patterning diamond, laser ablation and reactive-ion etching (RIE), are being developed to produce the required geometry. A variety of diagnostic techniques, including FTIR, SEM and AFM, have been used to characterize the diamonds.

SMEDLEY,J.; BEN-ZVI, I.; BOHON, J.; CHANG, X.; GROVER, R.; ISAKOVIC, A.; RAO, T.; WU, Q.

2007-11-26

197

Universal Signal Conditioning Amplifier  

NASA Technical Reports Server (NTRS)

The Technological Research and Development Authority (TRDA) and NASA-KSC entered into a cooperative agreement in March of 1994 to achieve the utilization and commercialization of a technology development for benefiting both the Space Program and U.S. industry on a "dual-use basis". The technology involved in this transfer is a new, unique Universal Conditioning Amplifier (USCA) used in connection with various types of transducers. The project was initiated in partnership with I-Net Corporation, Lockheed Martin Telemetry & Instrumentation (formerly Loral Test and Information Systems) and Brevard Community College. The project consists of designing, miniaturizing, manufacturing, and testing an existing prototype of USCA that was developed for NASA-KSC by the I-Net Corporation. The USCA is a rugged and field-installable self (or remotely)- programmable amplifier that works in combination with a tag random access memory (RAM) attached to various types of transducers. This summary report comprises performance evaluations, TRDA partnership tasks, a project summary, project milestones and results.

Kinney, Frank

1997-01-01

198

Design and demonstration of C-band static induction transistors in 4H silicon carbide  

Microsoft Academic Search

The biggest drawback of the static induction transistor (SIT) as a microwave amplifier is the relatively low transconductance and high input capacitance, leading to a low cut-off frequency (fT). The highest fT reported to date for SiC SITs is 4.1 GHz, thereby limiting these devices to L-band and S-band operation (< 2 GHz). In this presentation we provide guidelines for

J. P. Henning; A. Przadka; M. R. Melloch

1999-01-01

199

Plasma wave instability and amplification of terahertz radiation in field-effect-transistor arrays.  

PubMed

We show that the strong amplification of terahertz radiation takes place in an array of field-effect transistors at small DC drain currents due to hydrodynamic plasmon instability of the collective plasmon mode. Planar designs compatible with standard integrated circuit fabrication processes and strong coupling of terahertz radiation to plasmon modes in FET arrays make such arrays very attractive for potential applications in solid-state terahertz amplifiers and emitters. PMID:21693816

Popov, V V; Tsymbalov, G M; Shur, M S

2008-09-24

200

Lightwave systems with optical amplifiers  

Microsoft Academic Search

Fiber-optic communication systems using semiconductor laser amplifiers are investigated theoretically and experimentally. The noise and bit-error-rate characteristics of lightwave systems with optical amplifiers are calculated and the dependence of system performance on amplifier characteristics such as optical bandwidth, noise figure, gain, etc., is shown. Experimental results for both a 4-Gb\\/s optical preamplifier as well as coherent and direct detection systems

N. A. Olsson

1989-01-01

201

An NMOS input merged bipolar/sidewall-MOS transistor with a bypass sidewall MOS transistor (NBiBMOS transistor)  

NASA Astrophysics Data System (ADS)

A combined transistor structure is described with specific attention given to the device characteristics. Called an NBiBMOS transistor, the concept is based on the merging of a vertical n-p-n bipolar and two sidewall NMOS transitors into an NMOS input merged bipolar/sidewall-MOS transistor with a bypass sidewall NMOS transistor structure. NBiBMOS transistors are fabricated which have areas about 1.2 times those of single n-p-n transistors. The devices are tested and shown to have higher current drive capabilities than structures based on an NBiMOS and a separate NMOS bypass transistor. The body-source junction of the bypass NMOS transistor is forward-biased in the NBiBMOS structure, giving it the good current-drive characteristics.

Kenneth, K. O.; Lutsky, Joseph J.; Reif, Rafael L.; Lee, Hae-Seung

1992-11-01

202

Optical amplifier for space applications.  

PubMed

We describe an optical amplifier designed to amplify a spatially sampled component of an optical wavefront to kilowatt average power. The goal is means for implementing a strategy of spatially segmenting a large aperture wavefront, amplifying the individual segments, maintaining the phase coherence of the segments by active means, and imaging the resultant amplified coherent field. Applications of interest are the transmission of space solar power over multi-megameter distances, as to distant spacecraft, or to remote sites with no preexisting power grid. PMID:19401734

Fork, R L; Cole, S; Diffey, W; Gamble, L; Keys, A

1999-12-01

203

Wavelength tunable alexandrite regenerative amplifier  

SciTech Connect

We describe a wavelength tunable alexandrite regenerative amplifier which is used to amplify nanosecond slices from a single-frequency cw dye laser or 50-ps pulses emitted by a diode laser to energies in the 10-mJ range. The amplified 5-ns slices generated by the cw-pumped line narrowed dye laser are Fourier transform limited. The 50-ps pulses emitted by a gain-switched diode laser are amplified by more than 10 orders of magnitude in a single stage.

Harter, D.J.; Bado, P.

1988-11-01

204

Optical Amplifier for Space Applications  

NASA Technical Reports Server (NTRS)

We describe an optical amplifier designed to amplify a spatially sampled component of an optical wavefront to kilowatt average power. The goal is means for implementing a strategy of spatially segmenting a large aperture wavefront, amplifying the individual segments, maintaining the phase coherence of the segments by active means, and imaging the resultant amplified coherent field. Applications of interest are the transmission of space solar power over multi-megameter distances, as to distant spacecraft, or to remote sites with no preexisting power grid.

Fork, Richard L.; Cole, Spencer T.; Gamble, Lisa J.; Diffey, William M.; Keys, Andrew S.

1999-01-01

205

Reflex ring laser amplifier system  

DOEpatents

A laser pulse is injected into an unstable ring resonator-amplifier structure. Inside this resonator the laser pulse is amplified, spatially filtered and magnified. The laser pulse is recirculated in the resonator, being amplified, filtered and magnified on each pass. The magnification is chosen so that the beam passes through the amplifier in concentric non-overlapping regions similar to a single pass MOPA. After a number of passes around the ring resonator the laser pulse is spatially large enough to exit the ring resonator system by passing around an output mirror.

Summers, Mark A. (Livermore, CA)

1985-01-01

206

A new type of transistor: CBT  

Microsoft Academic Search

A transistor called the channel-base transistor (CBT), which is constructed by making channels through the base of the conventional bipolar junction transistors (BJTs), is proposed. In principle, a CBT can be treated as a combination of a BJT and a normally-off junction-type field-effect transistor (E-JFET). Silicon planer CBTs have been fabricated with BJTs on the same wafer for comparison. The

Bao-Wei Kang; Wei Zhao; Li-Min Dong; Yan Situ

1993-01-01

207

Laser amplifier developments at Mercury  

SciTech Connect

Electron-beam pumped laser amplifiers have been modified to address the mission of krypton-fluoride excimer laser technology development. Methods are described for improving the performance and reliability of two pre-existing amplifiers at minimal cost and time. Preliminary performance data are presented to support the credibility of the approach.

Rose, E.A.; Brucker, J.P.; Honig, E.M.; McCown, A.W.; Romero, V.O.; York, G.W.

1993-09-01

208

Improved radiographic image amplifier panel  

NASA Technical Reports Server (NTRS)

Layered image amplifier for radiographic /X ray and gamma ray/ applications, combines very high radiation sensitivity with fast image buildup and erasure capabilities by adding a layer of material that is both photoconductive and light-emitting to basic image amplifier and cascading this assembly with a modified Thorne panel.

Brown, R. L., Sr.

1968-01-01

209

The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers  

NASA Astrophysics Data System (ADS)

Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by using a UV-Ozone treatment to shift the threshold voltage and increase the current of the transistor under both compressive and tensile strain. An array of strain sensors which maps the strain field on a PVDF film surface is demonstrated in this work. The strain sensor experience inspires a tone analyzer built using distributed resonator architecture on a tensioned piezoelectric PVDF sheet. This sheet is used as both the resonator and detection element. Two architectures are demonstrated; one uses distributed directly addressed elements as a proof of concept, and the other integrates organic thin film transistor-based transimpedance amplifiers monolithically with the PVDF sheet to convert the piezoelectric charge signal into a current signal for future applications such as sound field imaging. The PVDF sheet material is instrumented along its length and the amplitude response at 15 sites is recorded and analyzed as a function of the frequency of excitation. The determination of the dominant frequency component of an incoming sound is demonstrated using linear system decomposition of the time-averaged response of the sheet using no time domain detection. Our design allows for the determination of the spectral composition of a sound using the mechanical signal processing provided by the amplitude response and eliminates the need for time-domain electronic signal processing of the incoming signal. The concepts of the PVDF strain sensor and the tone analyzer trigger the idea of an active matrix microphone through the integration of organic thin film transistors with a freestanding piezoelectric polymer sheet. Localized acoustic pressure detection is enabled by switch transistors and local transimpedance amplification built into the active matrix architecture. The frequency of detection ranges from DC to 15KHz; the bandwidth is extended using an architecture that provides for virtually zero gate/source and gate/drain capacitance at the sensing transistors and low overlap capacitance at the switch transistors. A series of measurements are taken to demonstrate localized

Hsu, Yu-Jen

210

Transistorized! The History of the Invention of the Transistor  

NSDL National Science Digital Library

Hosted by the Public Broadcasting Service (PBS) in collaboration with the American Institute of Physics and ScienCentral, Inc., this handsome Website serves as a companion to an upcoming PBS documentary, Transistorized!, to be aired November 8, 1999. The searchable site offers in-depth background to the history and science of transistors. An Interactives section includes a rubic's cube type of puzzle using elements from the Periodic Table, and a game which allows players to form their own semiconductor crystals. A hyper-linked glossary, a resources section with links to Websites, and a print bibliography round out this well-produced site.

American Institute of Physics.

211

The SIT saturation protected bipolar transistor  

Microsoft Academic Search

A novel transistor fabrication concept for saturating logic gate arrays is proposed. The idea involves using a static induction transistor (SIT) to protect against saturation. Current simulation tests show encouraging switching times for the saturation-protected transistor gates when compared to similar gates without protection by a SIT. The collector charge-storage effect was practically eliminated.

B. M. Wilamowski; R. H. Mattson; Z. J. Staszak

1984-01-01

212

Electroluminescence from a Single-Nanocrystal Transistor  

E-print Network

Electroluminescence from a Single-Nanocrystal Transistor Mark S. Gudiksen, Kristin N. Maher, Lian September 8, 2005 ABSTRACT We report the fabrication and characterization of light-emitting transistors- emitting transistors incorporating individual CdSe nano- crystals. Unlike the two-terminal devices employed

Heller, Eric

213

DECISION DIAGRAMS AND PASS TRANSISTOR LOGIC SYNTHESIS  

E-print Network

DECISION DIAGRAMS AND PASS TRANSISTOR LOGIC SYNTHESIS V. Bertacco S. Minato P. Verplaetse L. Benini by ARPA, under grant No. DABT63-95-C-0049. #12;Decision Diagrams and Pass Transistor Logic Synthesis V transistors and domino logic. The synthesis of these cells is based on BDD and ZBDD representations

De Micheli, Giovanni

214

Single Carbon Nanotube Transistor at GHz Frequency  

E-print Network

Single Carbon Nanotube Transistor at GHz Frequency J. Chaste,, L. Lechner,£ P. Morfin,, G. Fe operation of top-gated single carbon nanotube transistors. From transmission measurements in the 0.1-1.6 GHz effect transistors (CNT-FETs) are very attractive as ultimate, quantum limited devices. In particular

Plaçais, Bernard

215

High Performance Silicon Nanowire Field Effect Transistors  

Microsoft Academic Search

Silicon nanowires can be prepared with single-crystal structures, diameters as small as several nanometers and controllable hole and electron doping, and thus represent powerful building blocks for nanoelectronics devices such as field effect transistors. To explore the potential limits of silicon nanowire transistors, we have examined the influence of source-drain contact thermal annealing and surface passivation on key transistor properties.

Yi Cui; Zhaohui Zhong; Deli Wang; Wayne U. Wang; Charles M. Lieber

2003-01-01

216

Integration of Cell Membranes and Nanotube Transistors  

E-print Network

Integration of Cell Membranes and Nanotube Transistors Keith Bradley, Alona Davis, Jean. As the nanoelectronic device, we use a nanotube network transistor, which incorporates many individual nanotubes as transistors, and that the two systems interact. Further, we use the interaction to study the charge

Gruner, George

217

Super Matched Bipolar Transistor Pair Sets New  

E-print Network

Super Matched Bipolar Transistor Pair Sets New Standards for Drift and Noise Matched bipolar of the number of devices. The LM194 is the end result. It is a monolithic bipolar matched transistor pair which by a theoretical bipolar transistor model. The relationship between emitter-base voltage and collector cur- rent

Lanterman, Aaron

218

Electronics MOS Field-Effect Transistors  

E-print Network

ECEN 325 Electronics MOS Field-Effect Transistors Dr. Aydin Ilker Kar¸silayan Texas A&M University. Kar¸silayan - MOS Field-Effect Transistors 1 #12;CMOS Physical StructureCMOS Physical Structure Cross 325 Electronics - Aydin I. Kar¸silayan - MOS Field-Effect Transistors 2 #12;TAMU-ELEN-325 J. Silva

Palermo, Sam

219

Noise Characterization for Heterojunction Bipolar Transistors (HBTs)  

Microsoft Academic Search

A commonly used noise model for the bipolar junction transistor is the one developed by Hawkin who derived BJT noise model for minimum noise figure (Fmin) by taking the emitter junction capacitance (CTe) into account and by neglecting the bias dependence of the different transistor parameters. Although such a noise model was developed for homojunction transistors, it has been frequently

Kuo-Wei Liu; A. F. M. Anwar

2004-01-01

220

2014 Amplifier -1 FREQUENCY RESPONSE OF  

E-print Network

2014 Amplifier - 1 FREQUENCY RESPONSE OF AN AUDIO AMPLIFIER The objectives of this experiment are amplifier · To thoroughly bore you APPARATUS: Audio Amplifier (Circuit Chip), Computer with FFTScope software, Speaker, Power supply, Interconnecting Cables good high fidelity amplifier will have frequency

Glashausser, Charles

221

Magnetic vortex based transistor operations.  

PubMed

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan-out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT). PMID:24531235

Kumar, D; Barman, S; Barman, A

2014-01-01

222

Magnetic Vortex Based Transistor Operations  

PubMed Central

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan–out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT). PMID:24531235

Kumar, D.; Barman, S.; Barman, A.

2014-01-01

223

Differential InP HEMT MMIC Amplifiers Embedded in Waveguides  

NASA Technical Reports Server (NTRS)

Monolithic microwave integrated-circuit (MMIC) amplifiers of a type now being developed for operation at frequencies of hundreds of gigahertz contain InP high-electron-mobility transistors (HEMTs) in a differential configuration. The differential configuration makes it possible to obtain gains greater than those of amplifiers having the single-ended configuration. To reduce losses associated with packaging, the MMIC chips are designed integrally with, and embedded in, waveguide packages, with the additional benefit that the packages are compact enough to fit into phased transmitting and/or receiving antenna arrays. Differential configurations (which are inherently balanced) have been used to extend the upper limits of operating frequencies of complementary metal oxide/semiconductor (CMOS) amplifiers to the microwave range but, until now, have not been applied in millimeter- wave amplifier circuits. Baluns have traditionally been used to transform from single-ended to balanced configurations, but baluns tend to be lossy. Instead of baluns, finlines are used to effect this transformation in the present line of development. Finlines have been used extensively to drive millimeter- wave mixers in balanced configurations. In the present extension of the finline balancing concept, finline transitions are integrated onto the affected MMICs (see figure). The differential configuration creates a virtual ground within each pair of InP HEMT gate fingers, eliminating the need for inductive vias to ground. Elimination of these vias greatly reduces parasitic components of current and the associated losses within an amplifier, thereby enabling more nearly complete utilization of the full performance of each transistor. The differential configuration offers the additional benefit of multiplying (relative to the single-ended configuration) the input and output impedances of each transistor by a factor of four, so that it is possible to use large transistors that would otherwise have prohibitively low impedances. Yet another advantage afforded by the virtual ground of the differential configuration is elimination of the need for a ground plane and, hence, elimination of the need for back-side metallization of the MMIC chip. In turn, elimination of the back-side metallization simplifies fabrication, reduces parasitic capacitances, and enables mounting of the MMIC in the electric-field plane ("E-plane") of a waveguide. E-plane mounting is consistent with (and essential for the utility of) the finline configuration, in which transmission lines lie on a dielectric sheet in the middle of a broad side of the waveguide. E-plane mounting offers a combination of low loss and ease of assembly because no millimeter-wave wire bonds or transition substrates are required. Moreover, because there is no ground plane behind the MMIC, the impedance for the detrimental even (single-ended) mode is high, suppressing coupling to that mode. Still another advantage of E-plane mounting is that the fundamental waveguide mode is inherently differential, eliminating the need for a balun to excite the differential mode.

Kangaslahti, Pekka; Schlecht, Erich; Samoska, Lorene

2009-01-01

224

Optimization of Vertical Double-Diffused Metal-Oxide Semiconductor (VDMOS) Power Transistor Structure for Use in High Frequencies and Medical Devices  

PubMed Central

Power transistors, such as the vertical, double-diffused, metal-oxide semiconductor (VDMOS), are used extensively in the amplifier circuits of medical devices. The aim of this research was to construct a VDMOS power transistor with an optimized structure to enhance the operation of medical devices. First, boron was implanted in silicon by implanting unclamped inductive switching (UIS) and a Faraday shield. The Faraday shield was implanted in order to replace the gate-field parasitic capacitor on the entry part of the device. Also, implanting the UIS was used in order to decrease the effect of parasitic bipolar junction transistor (BJT) of the VDMOS power transistor. The research tool used in this study was Silvaco software. By decreasing the transistor entry resistance in the optimized VDMOS structure, power losses and noise at the entry of the transistor were decreased, and, by increasing the breakdown voltage, the lifetime of the VDMOS transistor lifetime was increased, which resulted in increasing drain flow and decreasing Ron. This consequently resulted in enhancing the operation of high-frequency medical devices that use transistors, such as Radio Frequency (RF) and electrocardiograph machines.

Farhadi, Rozita; Farhadi, Bita

2014-01-01

225

Design and development of a cryogenic semiconductor amplifier for interfacing RSFQ circuits at 4.2 K  

NASA Astrophysics Data System (ADS)

There is a great deal of interest in amplifiers with extremely high bandwidth, low noise and low power consumption which interface RSFQ circuits with commercial room temperature electronics or amplifying SFQ pulses. In this special application a hybrid amplifier should interface an RSFQ circuitry with a Josephson junction array quantizer chip (JA-Q) at 4.2 K. The input signal for the amplifier is generated by an RSFQ signal generator and the output signal fed-in to a Josephson array quantizer. A voltage gain of about 104 with a pattern frequency of 2 GHz for a good transfer of the SFQ pulses is required. Additionally, the JA-Q requires a high output current at low power consumption of the amplifier at the same time. Various hybrid amplifiers based on commercially available p-HEMT transistors in an embedded microwave design were designed and characterized. For the p-HEMT transistor characterization at cryogenic temperatures the biasing settings according to an optimum between voltage gain AV and low power consumption PV were determined. Thus a power consumption of PV = 2 mW and a voltage gain of about AV = 4 per stage were achieved. For a preamplifier and an amplifier concept a number of these stages were implemented in a microstrip and a coplanar transmission line design with a special matched interconnect taper towards the RSFQ components. Measurements of the amplifiers and the combination of the amplifiers and the JA-Q at 4.2 K showed their good performance without any disturbances of the quantized voltage steps.

Wuensch, S.; Crocoll, E.; Schubert, M.; Wende, G.; Meyer, H.-G.; Siegel, M.

2007-11-01

226

Silicon on insulator self-aligned transistors  

DOEpatents

A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

McCarthy, Anthony M.

2003-11-18

227

A MEMS-based precision operational amplifier  

E-print Network

Two main difficulties for amplifiers that attempt to make precision DC measurements are the inherent low-frequency noise of the amplifier and the leakage current of the amplifier input stage. This thesis presents a novel ...

Paik, Song-Hee Cindy, 1980-

2004-01-01

228

Microchannels as axonal amplifiers.  

PubMed

An implantable neural interface capable of reliable long-term high-resolution recording from peripheral nerves has yet to be developed. Device design is challenging because extracellular axonal signals are very small, decay rapidly with distance from the axon, and in myelinated fibres are concentrated close to nodes of Ranvier, which are around 1 mum long and spaced several hundred micrometers apart. We present a finite element model examining the electrical behavior of axons in microchannels, and demonstrate that confining axons in such channels substantially amplifies the extracellular signal. For example, housing a 10-microm myelinated axon in a 1-cm-long channel with a 1000-microm(2) cross section is predicted to generate a peak extracellular voltage of over 10 mV. Furthermore, there is little radial signal decay within the channel, and a smooth axial variation of signal amplitude along the channel, irrespective of node location. Additional benefits include a greater extracellular voltage generated by large myelinated fibres compared to small unmyelinated axons, and the reduction of gain to unity at the end of the channel which ensures that there can be no crosstalk with electrodes in other channels nearby. A microchannel architecture seems well suited to the requirements of a peripheral nerve interface. PMID:18334406

Fitzgerald, James J; Lacour, Stéphanie P; McMahon, Stephen B; Fawcett, James W

2008-03-01

229

Highly linear low noise amplifier  

E-print Network

transistor. Extensive Volterra series analysis using the harmonic input method has been performed to prove the concept of third harmonic cancellation and a design methodology has been proposed. The LNA has been designed to operate at 900MHz in TSMC 0.35um...

Ganesan, Sivakumar

2007-09-17

230

Boosting the voltage gain of graphene FETs through a differential amplifier scheme with positive feedback  

NASA Astrophysics Data System (ADS)

We study a possible circuit solution to overcome the problem of low voltage gain of short-channel graphene FETs. The circuit consists of a fully differential amplifier with a load made of a cross-coupled transistor pair. Starting from the device characteristics obtained from self-consistent ballistic quantum transport simulations, we explore the circuit parameter space and evaluate the amplifier performance in terms of dc voltage gain and voltage gain bandwidth. We show that the dc gain can be effectively improved by the negative differential resistance provided by the cross-coupled pair. Contact resistance is the main obstacle to achieving gain bandwidth products in the terahertz range. Limitations of the proposed amplifier are identified with its poor linearity and relatively large Miller capacitance.

Grassi, R.; Gnudi, A.; Di Lecce, V.; Gnani, E.; Reggiani, S.; Baccarani, G.

2014-10-01

231

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 2, FEBRUARY 2003 653 AlGaN/GaN HFET Power Amplifier Integrated With  

E-print Network

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 2, FEBRUARY 2003 653 AlGaN/GaN Abstract--In this paper, a high-efficiency and compact AlGaN/GaN heterojunction field-effect transistor measured by a load­pull mea- surement setup, the AlGaN/GaN HFET power amplifier has been designed

Itoh, Tatsuo

232

Power static induction transistor technology  

Microsoft Academic Search

Static induction transistor (SIT) is characterized by short channel structure and the relatively low impurity concentration in the channel, so that the potential profile near the source region is effectively controlled by the drain voltage as well as the gate voltage. Majority carriers in the source region are directly injected into the channel and their amount continuously increases with increasing

T. Ohmi

1979-01-01

233

Matching properties of MOS transistors  

Microsoft Academic Search

The matching properties of the threshold voltage, substrate factor, aud current factor of MOS transistors have been analyzed and measrrred. Improvements to the existing theory are giveu, as well as extensions for Iong-dktance matching and rotation of devices. Matching parameters of several processes are compared. The matching results have been verified by measurements and calculations on several basic circuits.

MARCEL J. M. PELGROM; AAD C. J. DUINMAIJER; P. G. WELBERS

1989-01-01

234

The four-gate transistor  

NASA Technical Reports Server (NTRS)

The four-gate transistor or G4-FET combines MOSFET and JFET principles in a single SOI device. Experimental results reveal that each gate can modulate the drain current. Numerical simulations are presented to clarify the mechanisms of operation. The new device shows enhanced functionality, due to the combinatorial action of the four gates, and opens rather revolutionary applications.

Mojarradi, M. M.; Cristoveanu, S.; Allibert, F.; France, G.; Blalock, B.; Durfrene, B.

2002-01-01

235

Recent Progress with Vertical Transistors  

Microsoft Academic Search

Vertical MOS transistors are a promising approach for channel lengths in the range of 100 to 25nm without the need for extreme fine line lithography. These devices provide high satura­ tion currents due to the short channel length and small lateral size due to the 3D-geometry. The channel is defined by epitaxy which can be grown with very good layer

Lothar Risch; Thomas Aeugle; Wolfgang Rosner

1997-01-01

236

Power amplifier leads MMIC line  

NASA Astrophysics Data System (ADS)

The first commercial offerings of Texas Instrument GaAs monolithic microwave integrated circuits (MMICs) are noted, including three amplifiers in the TGA8000 line. Model TGA8014 is a power amplifier with two large FETs connected by an interstage matching network; it puts out at least 0.4 W of power per chip from 6 to 18 GHz. It achieves this power with 7-dB typical gain. Model TGA8021, a low-noise amplifier based on three 300-micron FETs, exhibits a noise figure of only 2.5 dB and more than 24-dB gain per chip from 9 to 10 GHz. Model TGA8035, a general-purpose driver amplifier, generates 16 mW (+12 dBm) of outer power from 6 to 16 GHz with 12-dB typical gain and 7-dB typical noise figure.

Nelson, Steve; Mitchell, Bill; Halladay, Ralph; Beall, John; Lehmann, Randy

1986-12-01

237

Design of micropower operational amplifiers  

E-print Network

The operational amplifier is a fundamental building block for electronic devices and systems. The advancement of modern electronic technology has been setting more performance demand on the underlying integrated circuits ...

Rayanakorn, Surapap

2006-01-01

238

Enhanced performance CCD output amplifier  

DOEpatents

A low-noise FET amplifier is connected to amplify output charge from a che coupled device (CCD). The FET has its gate connected to the CCD in common source configuration for receiving the output charge signal from the CCD and output an intermediate signal at a drain of the FET. An intermediate amplifier is connected to the drain of the FET for receiving the intermediate signal and outputting a low-noise signal functionally related to the output charge signal from the CCD. The amplifier is preferably connected as a virtual ground to the FET drain. The inherent shunt capacitance of the FET is selected to be at least equal to the sum of the remaining capacitances.

Dunham, Mark E. (Los Alamos, NM); Morley, David W. (Santa Fe, NM)

1996-01-01

239

Statistical Mechanics of Amplifying Apparatus  

E-print Network

We implement Feynman's suggestion that the only missing notion needed for the puzzle of Quantum Measurement is the statistical mechanics of amplifying apparatus. We define a thermodynamic limit of quantum amplifiers which is a classically describable system in the sense of Bohr, and define macroscopic pointer variables for the limit system. Then we derive the probabilities of Quantum Measurement from the deterministic Schroedinger equation by the usual techniques of Classical Statistical Mechanics.

Joseph Johnson

2005-02-08

240

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

A flashlamp pumped dye laser suitable for use as a single stage amplifier is described. Particular emphasis is placed on the efforts to increase output pulse energy and improve the temporal profile of the injected pulse. By using high power thin film polarizers, output energies reach from 4 to 45 mJ. Various dispersive elements are used to develop an amplified pulse with an extremely clean temporal profile.

Davidson, F.; Hohman, J.

1984-01-01

241

A simple and reliable technique to characterize amplitude to phase modulation distortion for high-frequency amplifiers and nonlinear devices.  

PubMed

This paper presents a simple and reliable measurement system for characterizing the amplitude to phase modulation (AM-PM) characteristics of high frequency amplifiers and nonlinear devices. The AM-PM measurement system is based on a null detector implemented with a double balanced mixer, and requires a voltmeter and a calibrated phase shifter. A 12 W class A radio frequency power amplifier has been designed using a GaN transistor, and the AM-PM has been measured using both the method proposed in this work and the classical method with a calibrated vector network analyzer. A good correlation between both methods is observed, which validates the proposed method. PMID:24007089

Jauregui, Rigoberto; Portilla, Joaquin; Reynoso-Hernández, J A; Hirata-Flores, F I

2013-08-01

242

Input impedance and gain of a gigahertz amplifier using a dc superconducting quantum interference device in a quarter wave resonator  

NASA Astrophysics Data System (ADS)

Due to their superior noise performance, superconducting quantum interference devices (SQUIDs) are an attractive alternative to high electron mobility transistors for constructing ultra-low-noise microwave amplifiers for cryogenic use. We describe the use of a lumped element SQUID inductively coupled to a quarter wave resonator. The resonator acts as an impedance transformer and also makes it possible to accurately measure the input impedance and intrinsic microwave characteristics of the SQUID. We present a model for input impedance and gain, compare it to the measured scattering parameters, and describe how to use the model for the systematic design of low-noise microwave amplifiers with a wide range of performance characteristics.

Spietz, Lafe; Irwin, Kent; Aumentado, José

2008-08-01

243

Design of Low-Noise Output Amplifiers for P-channel Charge-Coupled Devices Fabricated on High-Resistivity Silicon  

SciTech Connect

We describe the design and optimization of low-noise, single-stage output amplifiers for p-channel charge-coupled devices (CCDs) used for scientific applications in astronomy and other fields. The CCDs are fabricated on high-resistivity, 4000–5000 -cm, n-type silicon substrates. Single-stage amplifiers with different output structure designs and technologies have been characterized. The standard output amplifier is designed with an n{sup +} polysilicon gate that has a metal connection to the sense node. In an effort to lower the output amplifier readout noise by minimizing the capacitance seen at the sense node, buried-contact technology has been investigated. In this case, the output transistor has a p{sup +} polysilicon gate that connects directly to the p{sup +} sense node. Output structures with buried-contact areas as small as 2 ?m × 2 ?m are characterized. In addition, the geometry of the source-follower transistor was varied, and we report test results on the conversion gain and noise of the various amplifier structures. By use of buried-contact technology, better amplifier geometry, optimization of the amplifier biases and improvements in the test electronics design, we obtain a 45% reduction in noise, corresponding to 1.7 e{sup ?} rms at 70 kpixels/sec.

Haque, S.; Frost, F. Dion R.; Groulx, R.; Holland, S.E.; Karcher, A.; Kolbe, W.F.; Roe, N. A.; Wang, G.; Yu, Y.

2011-12-22

244

Staggered Gain for 100+ GHz Broadband Amplifiers  

Microsoft Academic Search

A broadband amplifier is realized with cascaded stagger-tuned stages that are equalized for high bandwidth and low gain ripple. The staggered frequency response is demon- strated to improve the transimpedance limit of active circuits. The staggered response is demonstrated with a Darlington feed- back amplifier and a constructive wave amplifier, which achieves low group delay. The broadband amplifier is implemented

Joohwa Kim; James F. Buckwalter

2011-01-01

245

Four-Channel Differential AC Amplifier  

E-print Network

Four-Channel Differential AC Amplifier #12;INSTRUCTION MANUAL FOR HIGH-GAIN DIFFERENTIAL AMPLIFIER .......................................................................................................13 Each Differential AC Amplifier is delivered complete with: Four 3' Cables Rack Mount Hardware://www.a-msystems.com General Description Instrument Features The Four-Channel Differential AC Amplifier Model 1700 is designed

Kleinfeld, David

246

Handout 3 for EE-203 Differential Amplifiers  

E-print Network

Handout 3 for EE-203 Differential Amplifiers Sheikh Sharif Iqbal (Ref: Text book and KFUPM Online and applications associated with differential amplifiers. - Differential amplifier pair is a fundamental subcircuit used in the input stage of every operational amplifiers and many other linear integrated circuits

Iqbal, Sheikh Sharif

247

Radio-frequency measurement of an asymmetric single electron transistor  

NASA Astrophysics Data System (ADS)

Since the invention of the radio-frequency single-electron transistor (RF-SET) by Schoelkopf et al.,[1] most measurements have focused on the symmetric single electron transistor. It has been shown, however, that the symmetric SET has a rather low measurement efficiency in its normal working regime.[2][3] Recently, it has been pointed out that an asymmetric SET can be considerably more efficient than a symmetric SET as a quantum amplifier. In this case the measurement efficiency of the asymmetric SET becomes similar to that of the quantum point contact (QPC) detector which can approach the quantum limit. We investigate the asymmetric SET by fabricating Al/AlOx SETs with junction areas 40x40 nm^2 and 40x80nm^2 and total resistance of about 25k?. The results of RF and DC characterization of such asymmetric SETs will be discussed. [1] R. J. Schoelkopf, P. Wahlgren, A. A. Kozhevnikov, P. Delsing, D. E. Prober, Science, 280, 1242 (1998). [2] A. N. Korotkov, Phys. Rev. B, 63, 085312 (2001); 63, 115403 (2001). [3] D. Mozyrsky, I. Martin, and M. B. Hastings, Phys. Rev. Lett., 92, 018303 (2004). [4] S. A. Gurvitz and G. P. Berman, Phys. Rev. B, 72 , 073303(2005).

Ji, Zhongqing; Xue, Weiwei; Rimberg, A. J.

2007-03-01

248

Modeling Advanced Avalanche Effects for Bipolar Transistor Circuit Design  

E-print Network

Modeling Advanced Avalanche Effects for Bipolar Transistor Circuit Design Vladimir Milovanovi operating frequency and high output power of modern bipolar transistor circuits increase, designers are trying to exploit transistor operating regions where they would be able satisfy both conditions, namely

Technische Universiteit Delft

249

Metamorphosis of the transistor into a laser  

NASA Astrophysics Data System (ADS)

Based on the invention and operation of the transistor, the alloy diode laser, the quantum-well diode laser and the high-speed heterojunction bipolar transistor (HBT), we have invented and realized now a transistor laser (TL). The transistor laser is a three-terminal technology providing coupling and the coherent light emission in the transistor. The quantum-well (QW) heterojunction bipolar transistor laser, inherently a fast switching device, operates by transporting a small minority base charge density ˜1016 \\text{cm}-3 over a nanoscale base thickness (<900 \\text{A}) in picoseconds. The TL, owing to its fast recombination speed, its unique three-terminal configuration, and complementary nature of its optical and electrical collector output signals, enables resonance-free base current and collector voltage modulation. It is a compact source of electro-optical applications such as nonlinear signal mixing, frequency multiplication, negative feedback, and optoelectronics logic gates.

Feng, M.; Holonyak, N., Jr.

2015-01-01

250

High-Efficiency Envelope-Tracking W-CDMA Base-Station Amplifier Using GaN HFETs  

Microsoft Academic Search

A high-efficiency wideband code-division multiple-access (W-CDMA) base-station amplifier is presented using high-performance GaN heterostructure field-effect transistors to achieve high gain and efficiency with good linearity. For high efficiency, class J\\/E operation was employed, which can attain up to 80% efficiency over a wide range of input powers and power supply voltages. For nonconstant envelope input, the average efficiency is further

Donald F. Kimball; Jinho Jeong; Chin Hsia; Paul Draxler; Sandro Lanfranco; W. Nagy; K. Linthicum; L. E. Larson; P. M. Asbeck

2006-01-01

251

Input Impedance and Gain of a Gigahertz Amplifier Using a DC SQUID in a Quarter Wave Resonator  

Microsoft Academic Search

Due to their superior noise performance, SQUIDs are an attractive alternative\\u000ato high electron mobility transistors for constructing ultra-low-noise\\u000amicrowave amplifiers for cryogenic use. We describe the use of a lumped element\\u000aSQUID inductively coupled to a quarter wave resonator. The resonator acts as an\\u000aimpedance transformer and also makes it possible for the first time to\\u000aaccurately measure the

Lafe Spietz; Kent Irwin; Jose Aumentado

2008-01-01

252

Noise modeling and characterization for 1.5-V 1.8GHz SOI low-noise amplifier  

Microsoft Academic Search

SOI technology is a promising candidate for radio-frequency and microwave applications. In this work, SOI low-noise amplifiers (LNA) operating at 1.8-GHz under 1.5-V power supply are reported for the first time and the high-frequency noise characteristics are studied. A physical SOI thermal noise model is applied, and all the major noise sources associated with the transistors are modeled. SPICE simulation

Wei Jin; Weidong Liu; Chaohe Hai; Philip C. H. Chan; Chenming Hu

2001-01-01

253

Lowside driver's failure mechanism in a class-D amplifier under short circuit test and a robust driver device  

Microsoft Academic Search

The failure mechanism in a class-D audio amplifier under short-circuit test is analyzed. The damage, always in the low-side driver, is due to high current induced thermal run-away, which occurs during the shutdown after the over-current is detected. However, this high current doesn't come from the over-current itself since the current is limited to below that the transistor in the

Jian-Hsing Lee; J. R. Shih; Tong-Chern Ong; K. Wu

2010-01-01

254

Printing organic thin-film transistor technology  

Microsoft Academic Search

Si thin-film transistor (a-Si TFT and LTPS-TFT) and organic thin film transistor (OTFT) based on conjugated organic semiconductor have become attractive for use in flat panel display, smart cards, RFID tags and large area sensors. An organic thin-film transistor (OTFT) can be formed on plastic substrate due to its low process temperature, <150°C. Therefore, the manufacturing cost of OTFT is

Cheng-Chung Lee; Jia-Chong Ho; Tamg-Shiang Hu; Yu-Wu Wang

2005-01-01

255

Large-Signal Behavior of Junction Transistors  

Microsoft Academic Search

In the consideration of the junction transistor as a switch there are three characteristics of primary interest, the open impedance, the closed impedance, and the switching-time. A generalized two-terminal-pair theory of junction transistors is presented which is applicable, on a dc basis, in all regions of operation. Using this theory, the open and closed impedances of the transistor switch are

J. J. Ebers; J. L. Moll

1954-01-01

256

Single-transistor-clocked flip-flop  

DOEpatents

The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.

Zhao, Peiyi; Darwish, Tarek; Bayoumi, Magdy

2005-08-30

257

Junction Field-Effect Transistors  

NSDL National Science Digital Library

All About Circuits is a website that â??provides a series of online textbooks covering electricity and electronics.â? Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Junction Field-Effect Transistors, is the fifth chapter in Volume III â?? Semiconductors. A few of the topics covered in this chapter include: Meter check of a transistor and Active-mode operation. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

258

A resonant spin lifetime transistor  

NASA Astrophysics Data System (ADS)

We present a device concept for a spintronic transistor based on the spin relaxation properties a two-dimensional electron gas (2DEG). The device design is very similar to that of the Datta and Das spin transistor. However, our proposed device works in the diffusive regime rather than in the ballistic regime. This eases lithographical and processing requirements. The switching action is achieved through the biasing of a gate contact, which controls the lifetime of spins injected into the 2DEG from a ferromagnetic emitter, thus allowing the traveling spins to be either aligned with a ferromagnetic collector or randomizing them before collection. The device configuration can easily be turned into a memory and a readout head for magnetically stored information.

Cartoixà, X.; Ting, D. Z.-Y.; Chang, Y.-C.

2003-08-01

259

T-shaped emitter metal heterojunction bipolar transistors for submillimeter wave applications  

NASA Technical Reports Server (NTRS)

We report on the development of submillimeter wave transistors at JPL. The goal of the effort is to produce advance-reliable high frequency and high power amplifiers, voltage controlled oscillators, active multipliers, and high-speed mixed-signal circuits for space borne applications. The technology in development to achieve this is based on the Indium Phosphide (InP) Heterojunction Bipolar Transistor (HBT). The HBT is well suited for high speed, high power and uniform (across wafer) performance, due to the ability to tailor the material structure that electrons traverse through by well-controlled epitaxial growth methods. InP with its compatible lattice matched alloys such as indium gallium arsenide (InGaAs) and indium aluminium arsenide (InAlAs) provides for high electron velocities and high voltage breakdown capabilities. The epitaxial methods for this material system are fairly mature, however the implementation of high performance and reliable transistors are still under development by many laboratories. Our most recently fabricated, second generation mesa HBTs at JPL have extrapolated current gain cutoff frequency (FJ of 142GHz and power gain cutoff frequency (Fm,) of approximately 160GHz. This represents a 13% and 33% improvement of Ft and F, respectively, compared to the first generation mesa HBTs [l]. Analysis based on the University of California, Santa Barbara (UCSB) device model, RF device characteristics can be significantly improved by reducing base contact resistance and base metal contact width. We will describe our effort towards increasing transistor performance and yield.

Fung, Andy; Samoska, Lorene; Velebir, Jim; Siege, Peter; Rodwell, Mark; Paidi, Vamsi; Griffth, Zach; Urteaga, Miguel; Malik, Roger

2004-01-01

260

Static induction transistor image sensors  

Microsoft Academic Search

New image sensors, based on the operational principle of static induction transistor (SIT), are described in this paper. Two operational modes of SIT image sensors are described here. One is the electron-accumulation mode in which electrons are stored in the floating-cell region and another is the electron-depletion mode in which electrons are removed from the floating-cell region in response to

JUN-ICHI NISHIZAWA; TAKASHIGE TAMAMUSHI; TADAHIRO OHMI

1979-01-01

261

Amorphous Silicon Static Induction Transistor  

Microsoft Academic Search

A hydrogenated amorphous silicon (a-Si:H) Schottky-gate static induction transistor (SIT) is proposed and its characteristics are calculated for the case that the gap-state distribution in a-Si:H is constant near the Fermi level. It is found that an a-Si:H SIT with a gate spacing of about 5 mum can yield a sufficiently high ON\\/OFF current ratio of more than 108 when

Masato Ueda; Masataka Hirose; Yukio Osaka

1985-01-01

262

A Precision Silicon Transistor Thermometer  

Microsoft Academic Search

This article describes a mass-producible electronic thermometer employing an inexpensive transistor as a temperature sensor. The instrument features ±0.1°C accuracy from -50 to + 125°C; ±0.02°C stability throughout a 1000-day 125°C temperature cycle test; and probes that are freely interchangeable with no calibration by user. Probes need be factory-calibrated at only one temperature, and are based on a novel low-thermal-mass

Akira Ohte; Michiaki Yamagata

1977-01-01

263

Complementary junction heterostructure field-effect transistor  

DOEpatents

A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits. 10 figs.

Baca, A.G.; Drummond, T.J.; Robertson, P.J.; Zipperian, T.E.

1995-12-26

264

Complementary junction heterostructure field-effect transistor  

DOEpatents

A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits.

Baca, Albert G. (Albuquerque, NM); Drummond, Timothy J. (Albuquerque, NM); Robertson, Perry J. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

1995-01-01

265

A single transistor electrically alterable cell  

NASA Astrophysics Data System (ADS)

A novel single transistor electrically alterable memory cell is presented. The cell is based on floating gate technology using a double diffused (DMOS) transistor. Writing into the cell is achieved through hot electron injection while erasing is performed via Fowler-Nordheim tunneling through a thin oxide (100-A) region. The memory cell requires only one transistor because the write and erase voltages range between 15-20 and 25-30 V, respectively. The writeability of the cell is enhanced by the thin oxide region and dependent on the proximity of this region to the channel of the DMOS transistor.

Cacharelis, P.; Fong, E.; Torgerson, E.; Converse, M. J.; Denham, P.

1985-10-01

266

A single-atom transistor.  

PubMed

The ability to control matter at the atomic scale and build devices with atomic precision is central to nanotechnology. The scanning tunnelling microscope can manipulate individual atoms and molecules on surfaces, but the manipulation of silicon to make atomic-scale logic circuits has been hampered by the covalent nature of its bonds. Resist-based strategies have allowed the formation of atomic-scale structures on silicon surfaces, but the fabrication of working devices-such as transistors with extremely short gate lengths, spin-based quantum computers and solitary dopant optoelectronic devices-requires the ability to position individual atoms in a silicon crystal with atomic precision. Here, we use a combination of scanning tunnelling microscopy and hydrogen-resist lithography to demonstrate a single-atom transistor in which an individual phosphorus dopant atom has been deterministically placed within an epitaxial silicon device architecture with a spatial accuracy of one lattice site. The transistor operates at liquid helium temperatures, and millikelvin electron transport measurements confirm the presence of discrete quantum levels in the energy spectrum of the phosphorus atom. We find a charging energy that is close to the bulk value, previously only observed by optical spectroscopy. PMID:22343383

Fuechsle, Martin; Miwa, Jill A; Mahapatra, Suddhasatta; Ryu, Hoon; Lee, Sunhee; Warschkow, Oliver; Hollenberg, Lloyd C L; Klimeck, Gerhard; Simmons, Michelle Y

2012-04-01

267

REAP: Recycled Erbium Amplifier Pump  

NASA Astrophysics Data System (ADS)

We report a novel erbium doped fiber preamplifier design with a combination of high gain (greater than 40 dB) and low noise figure (3 dB) at 1556 nm for 80 mW of 980 nm pump power. The co-directional single pumped amplifier employs a composite two stage arrangement in which the second stage is pumped with recycled pump not used in the first stage. In addition, we contrast the amplifier performance trade-offs with the insertions of an isolator or a band pass filter or both in between the two amplifier sections. Finally, we demonstrate a receiver sensitivity of -37 dBm (156 photons/bit) with a 10 Gb/s optical preamplifier regenerator.

Delavaux, J.-M. P.; Nuyts, R. J.; Mizuhara, O.; Nagel, J. A.; Digiovanni, D. J.

1994-03-01

268

Optical amplifiers for coherent lidar  

NASA Technical Reports Server (NTRS)

We examine application of optical amplification to coherent lidar for the case of a weak return signal (a number of quanta of the return optical field close to unity). We consider the option that has been explored to date, namely, incorporation of an optical amplifier operated in a linear manner located after reception of the signal and immediately prior to heterodyning and photodetection. We also consider alternative strategies where the coherent interaction, the nonlinear processes, and the amplification are not necessarily constrained to occur in the manner investigated to date. We include the complications that occur because of mechanisms that occur at the level of a few, or one, quantum excitation. Two factors combine in the work to date that limit the value of the approach. These are: (1) the weak signal tends to require operation of the amplifier in the linear regime where the important advantages of nonlinear optical processing are not accessed, (2) the linear optical amplifier has a -3dB noise figure (SN(out)/SN(in)) that necessarily degrades the signal. Some improvement is gained because the gain provided by the optical amplifier can be used to overcome losses in the heterodyned process and photodetection. The result, however, is that introduction of an optical amplifier in a well optimized coherent lidar system results in, at best, a modest improvement in signal to noise. Some improvement may also be realized on incorporating more optical components in a coherent lidar system for purely practical reasons. For example, more compact, lighter weight, components, more robust alignment, or more rapid processing may be gained. We further find that there remain a number of potentially valuable, but unexplored options offered both by the rapidly expanding base of optical technology and the recent investigation of novel nonlinear coherent interference phenomena occurring at the single quantum excitation level. Key findings are: (1) insertion of linear optical amplifiers in well optimized conventional lidar systems offers modest improvements, at best, (2) the practical advantages of optical amplifiers, especially fiber amplifiers, such as ease of alignment, compactness, efficiency, lightweight, etc., warrant further investigation for coherent lidar, (3) the possibility of more fully optical lidar systems should be explored, (4) advantages gained by use of coherent interference of optical fields at the level of one, or a few, signal quanta should be explored, (5) amplification without inversion, population trapping, and use of electromagnetic induced transparency warrant investigation in connection with coherent lidar, (6) these new findings are probably more applicable to earth related NASA work, although applications to deep space should not be excluded, and (7) our own work in the Ultrafast Laboratory at UAH along some of the above lines of investigation, may be useful.

Fork, Richard

1996-01-01

269

Amplifier-Discriminator-Multiplexor card  

SciTech Connect

The Amplifier-Discriminator-Multiplexor (ADM) card described was designed for the External Muon Identifier at the 15 ft Bubble Chamber. The general scheme of the data readout of the External Muon Identifier is based on the use of a master clock. The ADM card serves to amplify the signals from the proportional tubes, discriminate them, latch the signals in parallel into a shift register. The data are then shifted out serially to the Time Digitizing System, using the master clock. The shift registers are loaded, and the latches are reset every sixteen cycles of the master clock. (LEW)

Graupman, D.

1986-02-01

270

A hybrid nanomemristor/transistor logic circuit capable of self-programming  

PubMed Central

Memristor crossbars were fabricated at 40 nm half-pitch, using nanoimprint lithography on the same substrate with Si metal-oxide-semiconductor field effect transistor (MOS FET) arrays to form fully integrated hybrid memory resistor (memristor)/transistor circuits. The digitally configured memristor crossbars were used to perform logic functions, to serve as a routing fabric for interconnecting the FETs and as the target for storing information. As an illustrative demonstration, the compound Boolean logic operation (A AND B) OR (C AND D) was performed with kilohertz frequency inputs, using resistor-based logic in a memristor crossbar with FET inverter/amplifier outputs. By routing the output signal of a logic operation back onto a target memristor inside the array, the crossbar was conditionally configured by setting the state of a nonvolatile switch. Such conditional programming illuminates the way for a variety of self-programmed logic arrays, and for electronic synaptic computing. PMID:19171903

Borghetti, Julien; Li, Zhiyong; Straznicky, Joseph; Li, Xuema; Ohlberg, Douglas A. A.; Wu, Wei; Stewart, Duncan R.; Williams, R. Stanley

2009-01-01

271

Random Number Generation Using Amplified Spontaneous Emission in a Fiber Amplifier  

E-print Network

Random Number Generation Using Amplified Spontaneous Emission in a Fiber Amplifier Julia C. Salevan · Photon counting · Amplified spontaneous emission #12;System Er:Yb EDFA Bandpass Filter (FBG) ( 0 = 1552

Anlage, Steven

272

Highly Efficient Amplifier for Ka-Band Communications  

NASA Technical Reports Server (NTRS)

An amplifier developed under a Small Business Innovation Research (SBIR) contract will have applications for both satellite and terrestrial communications. This power amplifier uses an innovative series bias arrangement of active devices to achieve over 40-percent efficiency at Ka-band frequencies with an output power of 0.66 W. The amplifier is fabricated on a 2.0- by 3.8-square millimeter chip through the use of Monolithic Microwave Integrated Circuit (MMIC) technology, and it uses state-of-the-art, Pseudomorphic High-Electron-Mobility Transistor (PHEMT) devices. Although the performance of the MMIC chip depends on these high-performance devices, the real innovations here are a unique series bias scheme, which results in a high-voltage chip supply, and careful design of the on-chip planar output stage combiner. This design concept has ramifications beyond the chip itself because it opens up the possibility of operation directly from a satellite power bus (usually 28 V) without a dc-dc converter. This will dramatically increase the overall system efficiency. Conventional microwave power amplifier designs utilize many devices all connected in parallel from the bias supply. This results in a low-bias voltage, typically 5 V, and a high bias current. With this configuration, substantial I(sup 2) R losses (current squared times resistance) may arise in the system bias-distribution network. By placing the devices in a series bias configuration, the total current is reduced, leading to reduced distribution losses. Careful design of the on-chip planar output stage power combiner is also important in minimizing losses. Using these concepts, a two-stage amplifier was designed for operation at 33 GHz and fabricated in a standard MMIC foundry process with 0.20-m PHEMT devices. Using a 20-V bias supply, the amplifier achieved efficiencies of over 40 percent with an output power of 0.66 W and a 16-dB gain over a 2-GHz bandwidth centered at 33 GHz. With a 28-V bias, a power level of 1.1 W was achieved with a 12-dB gain and a 36-percent efficiency. This represents the best reported combination of power and efficiency at this frequency. In addition to delivering excellent power and gain, this Ka-band MMIC power amplifier has an efficiency that is 10 percent greater than existing designs. The unique design offers an excellent match for spacecraft applications since the amplifier supply voltage is closely matched to the typical value of spacecraft bus voltage. These amplifiers may be used alone in applications of 1 W or less, or several may be combined or used in an array to produce moderate power, Ka-band transmitters with minimal power combining and less thermal stress owing to the combination of excellent efficiency and power output. The higher voltage operation of this design may also save mass and power because the dc-dc power converter is replaced with a simpler voltage regulator.

1996-01-01

273

Current vs. Voltage Feedback Amplifiers  

E-print Network

is a voltage source that is controlled by the potential difference between the two input terminals voltage to zero, hence the term voltage feedback. Gain Bandwidth Product Refer to the non-inverting gainCurrent vs. Voltage Feedback Amplifiers One question continuously troubles the analog design engi

Lanterman, Aaron

274

Raman amplifiers and fiber lasers  

Microsoft Academic Search

The summary form only given. Stimulated Raman scattering (SRS) is a process by which energy is transferred from one wavelength to the next through a nonlinear scattering process. This phenomenon can be used to Raman amplify signals in a telecommunication systems. In this tutorial, the process of SRS is reviewed; and the advantages of Raman pumping a transmission span, improved

C. Headley

2003-01-01

275

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

A flash lamp pumped dye laser suitable for use as an amplifier stage was developed. The desired output laser pulses are of nanosecond duration, tunable in center frequency, and of good optical quality. Its usefulness as a laser oscillator is emphasized, because it constitutes a compact, relatively efficient source of tunable dye laser light.

Davidson, F.

1983-01-01

276

Stroke amplifier for deformable mirrors  

PubMed Central

We demonstrate a simple optical configuration that amplifies the usable stroke of a deformable mirror. By arranging for the wavefront to traverse the deformable mirror more than once, we correct it more than once. The experimental implementation of the idea demonstrates a doubling of 2.0 and 2.04 by two different means. PMID:15495423

Webb, Robert H.; Albanese, Marc J.; Zhou, Yaopeng; Bifano, Thomas; Burns, Stephen A.

2010-01-01

277

PASOTRON{trademark} amplifier experiments  

SciTech Connect

Preliminary experimental studies are reported of an L-Band amplifier based on Hughes` Plasma-Assisted, Slow-Wave Oscillator (PASOTRON) technology. The amplifier system utilizes a hollow-cathode-plasma electron-gun, and a plasma-filled Slow-Wave Structure (SWS) to produce {>=} 100-{micro}sec-long, 50 to 75-kV, 30 to 100-A electron-beam pulses that propagate in a plasma channel without the use of any externally applied axial magnetic field. The electron-beam pulse coincides with a 100-{micro}sec-long RF drive signal provided by a 2.6-kW TWT, which is coupled into the amplifier upstream of the SWS. The SWS consists of a ring-bar design which is novel to the PASOTRON family of devices and is used for its short length compared to a helix. Simulations on HP`s High Frequency Structure Simulator were used to optimize the ring-bar SWS. Preliminary data are reported showing the new L-Band amplifiers gain, power, efficiency, and bandwidth. Methods of eliminating a Backward Wave Oscillation (BWO), which was found to limit the performance of the tube, are also presented.

Ponti, E.S.; Goebel, D.M.; Feicht, J.R.; Santoru, J. [Hughes Research Labs., Malibu, CA (United States); Eisenhart, R.L. [Eisenhart (Robert L.), Woodland Hills, CA (United States)

1995-11-01

278

Large Area Printing of Organic Transistors  

Microsoft Academic Search

Organic electronic systems offer the advantage of lightweight, mechanical flexibility and large area coverage at potentially lower manufacturing cost. Although the production of functioning plastic transistors using approaches such as ink jet, screen printing and stamping, has been described in the literature, no one-transistor layer has yet been fabricated using a technique appropriate for their commercial ization. The solution processability

Graciela B. Blanchet; J. A. Rogers; M. Lefenfeld; C. R. Fincher; Jueh-Lin Loo

2003-01-01

279

The SIT Saturation protected bipolar transistor  

Microsoft Academic Search

A novel concept for a transistor was invented, introducing an idea for protection against saturation. It involves the use of a static induction transistor (SIT). Simulation showed encouraging switching times when compared to similar gates without protection, while the charge storage was practically eliminated.

B. M. Wilamowski; R. H. Mattson; Z. J. Staszak

1984-01-01

280

Aesop: a tool for automated transistor sizing  

Microsoft Academic Search

This work addresses the problem of automating the electrical optimization of combinatorial MOS circuits. Improvements to a circuit's speed, area and power consumption are sought through modifications to the transistor sizes in the circuit; no changes in the circuit structure, number of gates or clocking are introduced. Linear algorithms are presented for computing optimal transistor sizes to minimize delay, area

Kye S. Hedlund

1987-01-01

281

MAGNETOELECTRIC RESONANT GATE TRANSISTOR , R. Misra2  

E-print Network

MAGNETOELECTRIC RESONANT GATE TRANSISTOR F. Li1* , R. Misra2 , Z. Fang1 , C. Curwen1 , Y. Wu1 , Q medical imaging and diagnosis. Here, we present an integrated magnetoelectric resonant gate transistor (ME applications. INTRODUCTION Magnetoelectric (ME) effect [1] is defined as the induction of electrical

Yener, Aylin

282

Transparent and Flexible Carbon Nanotube Transistors  

E-print Network

Transparent and Flexible Carbon Nanotube Transistors E. Artukovic, M. Kaempgen, D. S. Hecht, S We report the fabrication of transparent and flexible transistors where both the bottom gate and the conducting channel are carbon nanotube networks of different densities and Parylene N is the gate insulator

Gruner, George

283

Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission  

NASA Technical Reports Server (NTRS)

For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

Sullivan, Gerry

2001-01-01

284

Three MMIC Amplifiers for the 120-to-200 GHz Frequency Band  

NASA Technical Reports Server (NTRS)

Closely following the development reported in the immediately preceding article, three new monolithic microwave integrated circuit (MMIC) amplifiers that would operate in the 120-to-200-GHz frequency band have been designed and are under construction at this writing. The active devices in these amplifiers are InP high-electron-mobility transistors (HEMTs). These amplifiers (see figure) are denoted the LSLNA150, the LSA200, and the LSA185, respectively. Like the amplifiers reported in the immediately preceding article, the LSLNA150 (1) is intended to be a prototype of low-noise amplifiers (LNAs) to be incorporated into spaceborne instruments for sensing cosmic microwave background radiation and (2) has potential for terrestrial use in electronic test equipment, passive millimeter-wave imaging systems, radar receivers, communication receivers, and systems for detecting hidden weapons. The HEMTs in this amplifier were fabricated according to 0.08- m design rules of a commercial product line of InP HEMT MMICs at HRL Laboratories, LLC, with a gate geometry of 2 fingers, each 15 m wide. On the basis of computational simulations, this amplifier is designed to afford at least 15 dB of gain, with a noise figure of no more than about 6 dB, at frequencies from 120 to 160 GHz. The measured results of the amplifier are shown next to the chip photo, with a gain of 16 dB at 150 GHz. Noise figure work is ongoing. The LSA200 and the LSA185 are intended to be prototypes of transmitting power amplifiers for use at frequencies between about 180 and about 200 GHz. These amplifiers have also been fabricated according to rules of the aforesaid commercial product line of InP HEMT MMICs, except that the HEMTs in these amplifiers are characterized by a gate geometry of 4 fingers, each 37 m wide. The measured peak performance of the LSA200 is characterized by a gain of about 1.4 dB at a frequency of 190 GHz; the measured peak performance of the LSA185 is characterized by a gain of about 2.7 dB at a frequency of 181 GHz. The measured gain results of each chip are shown next to their respective photos.

Samoska, Lorene; Schmitz, Adele

2009-01-01

285

Universal power transistor base drive control unit  

DOEpatents

A saturation condition regulator system for a power transistor which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition.

Gale, Allan R. (Allen Park, MI); Gritter, David J. (Racine, WI)

1988-01-01

286

Universal power transistor base drive control unit  

DOEpatents

A saturation condition regulator system for a power transistor is disclosed which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition. 2 figs.

Gale, A.R.; Gritter, D.J.

1988-06-07

287

Ambipolar MoTe2 transistors and their applications in logic circuits.  

PubMed

We report ambipolar charge transport in ?-molybdenum ditelluride (MoTe2 ) flakes, whereby the temperature dependence of the electrical characteristics was systematically analyzed. The ambipolarity of the charge transport originated from the formation of Schottky barriers at the metal/MoTe2 contacts. The Schottky barrier heights as well as the current on/off ratio could be modified by modulating the electrostatic fields of the back-gate voltage (Vbg) and drain-source voltage (Vds). Using these ambipolar MoTe2 transistors we fabricated complementary inverters and amplifiers, demonstrating their feasibility for future digital and analog circuit applications. PMID:24692079

Lin, Yen-Fu; Xu, Yong; Wang, Sheng-Tsung; Li, Song-Lin; Yamamoto, Mahito; Aparecido-Ferreira, Alex; Li, Wenwu; Sun, Huabin; Nakaharai, Shu; Jian, Wen-Bin; Ueno, Keiji; Tsukagoshi, Kazuhito

2014-05-28

288

Charge noise in graphene transistors.  

PubMed

We report an experimental study of 1/f noise in liquid-gated graphene transistors. We show that the gate dependence of the noise is well described by a charge-noise model, whereas Hooge's empirical relation fails to describe the data. At low carrier density, the noise can be attributed to fluctuating charges in close proximity to the graphene, while at high carrier density it is consistent with noise due to scattering in the channel. The charge noise power scales inversely with the device area, and bilayer devices exhibit lower noise than single-layer devices. In air, the observed noise is also consistent with the charge-noise model. PMID:20373788

Heller, Iddo; Chatoor, Sohail; Männik, Jaan; Zevenbergen, Marcel A G; Oostinga, Jeroen B; Morpurgo, Alberto F; Dekker, Cees; Lemay, Serge G

2010-05-12

289

Multicore Processor Cluster Based Sleep Transistor Sizing Considering Delay Profile  

E-print Network

Multicore Processor Cluster Based Sleep Transistor Sizing Considering Delay Profile Huang Huang, Jeffrey Fan* Abstract-- This paper proposed a novel method to size the sleep transistor by considering and the total size of sleep transistors can be dramatically reduced. In theory, the size of sleep transistor can

Fan, Jeffrey

290

CMOS Transistor Mismatch Model valid from Weak to Strong Inversion  

E-print Network

CMOS Transistor Mismatch Model valid from Weak to Strong Inversion Teresa Serrano and PMOS transistors for 30 different geometries has been done with this continuos model. The model is able of transistor mismatch is crucial for precision analog design. Using very reduced transistor geometries produces

Barranco, Bernabe Linares

291

Sleep Transistor Sizing and Control for Resonant Supply  

E-print Network

1 Sleep Transistor Sizing and Control for Resonant Supply Noise Damping Jie Gu, Hanyong Eom@ece.umn.edu www.umn.edu/~chriskim/ #12;2 Outline · Introduction · Conventional Sizing of Sleep Transistors · Sleep Transistor Sizing Considering Resonant Supply Damping · Adaptive Sleep Transistor Circuit · Conclusions #12

Kim, Chris H.

292

New architecture for RF power amplifier linearization  

E-print Network

Power amplifier linearization has become an important part of the transmitter system as 3G and developing 4G communication standards require higher linearity than ever before. The thesis proposes two power amplifier ...

Boo, Hyun H

2009-01-01

293

Uniplanar microwave balanced mixers and amplifiers  

E-print Network

The completely uniplanar broadband singly balanced diode mixers and FET amplifiers, which utilize coplanar waveguide and slot line as the main transmission lines, are presented. These mixers and amplifiers have several desirable features...

Hsu, Pang-Cheng

1995-01-01

294

2.4 GHz CMOS Power Amplifier with Mode-Locking Structure to Enhance Gain  

PubMed Central

We propose a mode-locking method optimized for the cascode structure of an RF CMOS power amplifier. To maximize the advantage of the typical mode-locking method in the cascode structure, the input of the cross-coupled transistor is modified from that of a typical mode-locking structure. To prove the feasibility of the proposed structure, we designed a 2.4?GHz CMOS power amplifier with a 0.18??m RFCMOS process for polar transmitter applications. The measured power added efficiency is 34.9%, while the saturated output power is 23.32?dBm. The designed chip size is 1.4 × 0.6?mm2. PMID:25045755

2014-01-01

295

Solid state ku-band power amplifier  

NASA Technical Reports Server (NTRS)

The design, fabrication, and testing of two types of IMPATT diode reflection amplifiers and a transmission amplifier are given. The Ku-band IMPATT diode development is discussed. Circuitry and electrical performance of the final version of the Ku-band amplifier is described. Construction details and an outline and mounting drawing are presented.

Bowers, H. C.; Lockyear, W. H.

1972-01-01

296

Operational Amplifier Circuits ECE 2100 Circuit Analysis  

E-print Network

1 Operational Amplifier Circuits ECE 2100 Circuit Analysis updated 11 May 2012 Pre voltage source Vin assuming that the operational amplifier is not saturated (thus there is negative of this amplifier circuit? 2. Use your SPICE engine to plot Vout as a function of Vin as Vin is varied from -2V to 2

Miller, Damon A.

297

Remote Acquisition Amplifier For 50-Ohm Cable  

NASA Technical Reports Server (NTRS)

Buffer-amplifier unit designed to drive 50-Ohm cables up to 100 ft. (30 m) long, compensating for attenuation in cables and enabling remote operation of oscilloscopes. Variable resistor provides for adjustment of gain of amplifier, such that overall gain from input terminals of amplifier to output end of cable set to unity.

Amador, Jose J.

1995-01-01

298

High frequency, high voltage MOSFET isolation amplifier  

Microsoft Academic Search

The present invention utilizes a high voltage isolation amplifier as the drive means for the inductor of a programmable microwave attenuator. A pair of power MOSFET devices are used to control the current flow through a magnetic yoke. The power MOSPET devices cooperate with floating operational amplifier drive circuits to act as a transconductance amplifiers and pass a load current

1986-01-01

299

Efficient Amplifiers and Bounded Degree Optimization  

E-print Network

Efficient Amplifiers and Bounded Degree Optimization Piotr Berman \\Lambda Marek Karpinski y Abstract This paper studies the existence of efficient (small size) amplifiers for prov­ ing explicit an explicit construction for such amplifiers. We use this construction to improve the currently best known

Eckmiller, Rolf

300

NASA developments in solid state power amplifiers  

NASA Technical Reports Server (NTRS)

Over the last ten years, NASA has undertaken an extensive program aimed at development of solid state power amplifiers for space applications. Historically, the program may be divided into three phases. The first efforts were carried out in support of the advanced communications technology satellite (ACTS) program, which is developing an experimental version of a Ka-band commercial communications system. These first amplifiers attempted to use hybrid technology. The second phase was still targeted at ACTS frequencies, but concentrated on monolithic implementations, while the current, third phase, is a monolithic effort that focusses on frequencies appropriate for other NASA programs and stresses amplifier efficiency. The topics covered include: (1) 20 GHz hybrid amplifiers; (2) 20 GHz monolithic MESFET power amplifiers; (3) Texas Instruments' (TI) 20 GHz variable power amplifier; (4) TI 20 GHz high power amplifier; (5) high efficiency monolithic power amplifiers; (6) GHz high efficiency variable power amplifier; (7) TI 32 GHz monolithic power amplifier performance; (8) design goals for Hughes' 32 GHz variable power amplifier; and (9) performance goals for Hughes' pseudomorphic 60 GHz power amplifier.

Leonard, Regis F.

1990-01-01

301

Valves Based on Amplified Piezoelectric Actuators  

Microsoft Academic Search

Amplified Piezo Actuators have been developed at CEDRAT TECHNOLOGIES for several years and found several applications in space. Their well-known advantages (rapid response and precise positioning) have been used in valve designs to obtain either rapid or fine proportional valves. A first gas valve is using a small amplified piezo actuator and is further driven with a switched amplifier to

R. Le Letty; N. Lhermet; G. Patient; F. Claeyssen; M. Lang

2004-01-01

302

Using Nondeterminism to Amplify Hardness Alexander Healy  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Harvard University Emanuele Viola ABSTRACT We revisit the problem of hardness amplification in NP, as recently studied by O) , we amplify to hardness 1/2 - 1/n(1) . 2. If s(n) = 2n(1) , we amplify to hardness 1/2-1/2n(1) . 3

Viola, Emanuele

303

Realising high-current gain p-n-p transistors using a novel surface accumulation layer transistor  

E-print Network

Realising high-current gain p-n-p transistors using a novel surface accumulation layer transistor accumulation layer transistor (SALTran) on SOI, which uses the concept of surface accumulation of holes near of the previously published conventional p-n-p lateral bipolar transistor (LBT) structure. From the simulation

Kumar, M. Jagadesh

304

Random Number Generation Using Amplified Spontaneous Emission in a Fiber Amplifier  

E-print Network

. Results Yb/Er FA: Ytterbium/Erbium Fiber Amplifier BPF: Band Pass Filter EDFA: Erbium Doped FiberRandom Number Generation Using Amplified Spontaneous Emission in a Fiber Amplifier Julia C. Salevan spontaneous emission in a fiber amplifier as our random source. System Conclusions and Future Work Statistical

Anlage, Steven

305

The design of a frequency modulated transistor oscillator  

E-print Network

operating conditions. The most serious ca~se of frequency instability in transis- tor oscillators is the effect of temperature. Temperature not only affects the tuned oirouit but the transistor itselfp since the transistor parameters also vary.... Altering the operating point of the transistor will change both the emitter current and the collector voltage~ consequently, almost all of the parameters of the transistor will be affeoted. In oscilla- tors, a change in any transistor parameter...

Fisher, Phil Dewey

1959-01-01

306

Top-down pass-transistor logic design  

Microsoft Academic Search

The pass-transistor based cell library and synthesis tool are constructed, for the first time, to clarify the potential of top-down pass-transistor logic. The entire scheme is called LEAP (Lean Integration with Pass-Transistors). The feature of a pass-transistor based cell is its multiplexer function and the open-drain structure. This cell has the flexibility of transistor level circuit design and compatibility with

K. Yano; Y. Sasaki; K. Rikino; K. Seki

1996-01-01

307

High power gas laser amplifier  

DOEpatents

A high power output CO.sub.2 gas laser amplifier having a number of sections, each comprising a plurality of annular pumping chambers spaced around the circumference of a vacuum chamber containing a cold cathode, gridded electron gun. The electron beam from the electron gun ionizes the gas lasing medium in the sections. An input laser beam is split into a plurality of annular beams, each passing through the sections comprising one pumping chamber.

Leland, Wallace T. (Los Alamos, NM); Stratton, Thomas F. (Los Alamos, NM)

1981-01-01

308

Electrical coupling between cells and graphene transistors.  

PubMed

In this work, both experimental data and a model are presented on the coupling between living cells and graphene solution-gated field-effect transistors. Modified HEK 293 cells are successfully cultured on graphene transistor arrays and electrically accessed by the patch clamp method. Transistor recordings are presented, showing the opening and closing of voltage-gated potassium ion channels in the cell membrane. The experimental data is compared with the broadly used standard point-contact model. The ion dynamics in the cell-transistor cleft are analyzed to account for the differences between the model and the experimental data revealing a significant increase in the total ionic strength in the cleft. In order to describe the influence of the ion concentration resulting from the cell activity, the ion-sensitivity of graphene solution-gated field-effect transistors is investigated experimentally and modelled by considering the screening effect of the ions on the surface potential at the graphene/electrolyte interface. Finally, the model of the cell-transistor coupling is extended to include the effect of ion accumulation and ion sensitivity. The experimental data shows a very good agreement with this extended model, emphasizing the importance of considering the ion concentration in the cleft to properly understand the cell-transistor coupling. PMID:25408432

Hess, Lucas H; Becker-Freyseng, Christoph; Wismer, Michael S; Blaschke, Benno M; Lottner, Martin; Rolf, Felix; Seifert, Max; Garrido, Jose A

2015-04-01

309

High power regenerative laser amplifier  

DOEpatents

A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

1994-02-08

310

High power regenerative laser amplifier  

DOEpatents

A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

Miller, John L. (Livermore, CA); Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Dublin, CA); Zapata, Luis E. (Livermore, CA)

1994-01-01

311

Log amplifier with pole-zero compensation  

DOEpatents

A logarithmic amplifier circuit provides pole-zero compensation for improved stability and response time over 6-8 decades of input signal frequency. The amplifier circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedback loop. The compensated output signal is provided by the second operational amplifier with the log elements, i.e., resistors, and the compensating capacitors in each of the feedback loops having equal values so that each break point or pole is offset by a compensating break point or zero.

Brookshier, William (Downers Grove, IL)

1987-01-01

312

Atomic quantum transistor based on swapping operation  

E-print Network

We propose an atomic quantum transistor based on exchange by virtual photons between two atomic systems through the control gate-atom. The quantum transistor is realized in two QED cavities coupled in nano-optical scheme. We have found novel effect in quantum dynamics of coupled three-node atomic system which provides control-SWAP(\\theta) processes in quantum transistor operation. New possibilities of quantum entanglement in an example of bright and dark qubit states have been demonstrated for quantum transport in the atomic chain. Potentialities of the proposed nano-optical design for quantum computing and fundamental issues of multi-atomic physics are also discussed.

Sergey A. Moiseev; Sergey N. Andrianov; Eugene S. Moiseev

2011-08-31

313

Pass-transistor very large scale integration  

NASA Technical Reports Server (NTRS)

Logic elements are provided that permit reductions in layout size and avoidance of hazards. Such logic elements may be included in libraries of logic cells. A logical function to be implemented by the logic element is decomposed about logical variables to identify factors corresponding to combinations of the logical variables and their complements. A pass transistor network is provided for implementing the pass network function in accordance with this decomposition. The pass transistor network includes ordered arrangements of pass transistors that correspond to the combinations of variables and complements resulting from the logical decomposition. The logic elements may act as selection circuits and be integrated with memory and buffer elements.

Maki, Gary K. (Inventor); Bhatia, Prakash R. (Inventor)

2004-01-01

314

Transistors using crystalline silicon devices on glass  

DOEpatents

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

McCarthy, Anthony M. (Menlo Park, CA)

1995-01-01

315

Nanoscale Transistors: Advanced VLSI Devices (Introductory Lecture)  

NSDL National Science Digital Library

Contributed by Mark Lundstrom of Purdue University, this introductory lecture to nanoscale transistors is available both as a Flash video with audio and as presentation slides in PDF form (the links to these are on the right hand side of the page). The lecture introduces the course, which "examines the device physics of advanced transistors and the process, device, circuit, and systems considerations that enter into the development of new integrated circuit technologies." This is a helpful resource for nanotechnology instructors looking to introduce the concept of nanoscale transistors into their classrooms. For more from this course (lectures, assignments, etc.) click the Course Information Website link.

Lundstrom, Mark

316

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from April 1, 1985 to Sept. 30, 1985 under NASA grant NAS1-441 entitled direct solar pumped iodine laser amplifier. During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) the radiation characteristics of solar simulator and the parametric characteristics of photodissociation iodine laser continuously pumped by a Vortek solar simulator; (2) kinetic modeling of a solar pumped iodine laser amplifier; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K. S.

1985-01-01

317

A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator  

SciTech Connect

A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P. D. [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)] [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)

2013-09-15

318

A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator.  

PubMed

A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system. PMID:24089846

Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P D

2013-09-01

319

A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator  

NASA Astrophysics Data System (ADS)

A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P. D.

2013-09-01

320

High-Performance Solid-State W-Band Power Amplifiers  

NASA Technical Reports Server (NTRS)

The figure shows one of four solid-state power amplifiers, each capable of generating an output power greater than or equal to 240 mW over one of four overlapping frequency bands from 71 to 106 GHz. (The bands are 71 to 84, 80 to 92, 88 to 99, and 89 to 106 GHz.) The amplifiers are designed for optimum performance at a temperature of 130 K. These amplifiers were developed specifically for incorporation into frequency-multiplier chains in local oscillators in a low-noise, far-infrared receiving instrument to be launched into outer space to make astrophysical observations. The designs of these amplifiers may also be of interest to designers and manufacturers of terrestrial W-band communication and radar systems. Each amplifier includes a set of six high-electron-mobility transistor (HEMT) GaAs monolithic microwave integrated-circuit (MMIC) chips, microstrip cavities, and other components packaged in a housing made from A-40 silicon-aluminum alloy. This alloy was chosen because, for the original intended spacecraft application, it offers an acceptable compromise among the partially competing requirements for high thermal conductivity, low mass, and low thermal expansion. Problems that were solved in designing the amplifiers included designing connectors and packages to fit the available space; designing microstrip signal-power splitters and combiners; matching of impedances across the frequency bands; matching of the electrical characteristics of those chips installed in parallel power-combining arms; control and levelling of output power across the bands; and designing the MMICs, microstrips, and microstrip cavities to suppress tendencies toward oscillation in several modes, both inside and outside the desired frequency bands.

Gaier, Todd; Samoska, Lorene; Wells, Mary; Ferber, Robert; Pearson, John; Campbell, April; Peralta, Alejandro; Swift, Gerald; Yocum, Paul; Chung, Yun

2003-01-01

321

TA 7.4: A High-Swing 2V CMOSOperational Amplifier with Gain Enhancement usinga Replica Amplifier  

E-print Network

TA 7.4: A High-Swing 2V CMOSOperational Amplifier with Gain Enhancement usinga Replica Amplifier output resistance, butby matching main andreplica amplifiers, high effectiveopen-stageamplifiercircuitdemon- strates gain enhancementfor low-voltage applications. Consider a transconductance amplifier

Lee, Hae-Seung "Harry"

322

A correlated nickelate synaptic transistor.  

PubMed

Inspired by biological neural systems, neuromorphic devices may open up new computing paradigms to explore cognition, learning and limits of parallel computation. Here we report the demonstration of a synaptic transistor with SmNiO?, a correlated electron system with insulator-metal transition temperature at 130°C in bulk form. Non-volatile resistance and synaptic multilevel analogue states are demonstrated by control over composition in ionic liquid-gated devices on silicon platforms. The extent of the resistance modulation can be dramatically controlled by the film microstructure. By simulating the time difference between postneuron and preneuron spikes as the input parameter of a gate bias voltage pulse, synaptic spike-timing-dependent plasticity learning behaviour is realized. The extreme sensitivity of electrical properties to defects in correlated oxides may make them a particularly suitable class of materials to realize artificial biological circuits that can be operated at and above room temperature and seamlessly integrated into conventional electronic circuits. PMID:24177330

Shi, Jian; Ha, Sieu D; Zhou, You; Schoofs, Frank; Ramanathan, Shriram

2013-01-01

323

Quantum Transport: Atom to Transistor  

NSDL National Science Digital Library

Purdue University offers this course to graduate students as a way to introduce students with little or no background in the fields of quantum and statistical mechanics to the world of nanotechnology by using familiar electrical engineering related concepts. This course uses MATLAB, a mathematical software package, to provide examples to illustrate these complex ideas in a semester long course. There are forty-two lectures available using Microsoft Media Player, under the â??Video Onlyâ?? link on this website. Each lecture references a specific chapter from the course book, Quantum Transport: Atom to Transistor. This would be a good resource for educators, students, or electrical engineering aficionados looking to increase their knowledge on quantum mechanics.

Datta, Supriyo, 1954-

324

A correlated nickelate synaptic transistor  

NASA Astrophysics Data System (ADS)

Inspired by biological neural systems, neuromorphic devices may open up new computing paradigms to explore cognition, learning and limits of parallel computation. Here we report the demonstration of a synaptic transistor with SmNiO3, a correlated electron system with insulator-metal transition temperature at 130°C in bulk form. Non-volatile resistance and synaptic multilevel analogue states are demonstrated by control over composition in ionic liquid-gated devices on silicon platforms. The extent of the resistance modulation can be dramatically controlled by the film microstructure. By simulating the time difference between postneuron and preneuron spikes as the input parameter of a gate bias voltage pulse, synaptic spike-timing-dependent plasticity learning behaviour is realized. The extreme sensitivity of electrical properties to defects in correlated oxides may make them a particularly suitable class of materials to realize artificial biological circuits that can be operated at and above room temperature and seamlessly integrated into conventional electronic circuits.

Shi, Jian; Ha, Sieu D.; Zhou, You; Schoofs, Frank; Ramanathan, Shriram

2013-10-01

325

Development of gallium nitride power transistors  

E-print Network

GaN-based high-voltage transistors have outstanding properties for the development of ultra-high efficiency and compact power electronics. This thesis describes a new process technology for the fabrication of GaN power ...

Piedra, Daniel, M. Eng. Massachusetts Institute of Technology

2011-01-01

326

Spin effects in single-electron transistors  

E-print Network

Basic electron transport phenomena observed in single-electron transistors (SETs) are introduced, such as Coulomb-blockade diamonds, inelastic cotunneling thresholds, the spin-1/2 Kondo effect, and Fano interference. With ...

Granger, Ghislain

2005-01-01

327

RF SMALL SIGNAL AVALANCHE CHARACTERIZATION AND REPERCUSSIONS ON BIPOLAR TRANSISTOR CIRCUIT DESIGN  

E-print Network

RF SMALL SIGNAL AVALANCHE CHARACTERIZATION AND REPERCUSSIONS ON BIPOLAR TRANSISTOR CIRCUIT DESIGN transistor circuits, electronic circuit designers are exploring regimes of transistor operation that meet on some important transistor properties like unilateral and maximum available power gain, as well

Technische Universiteit Delft

328

A 2.4GHz, 2.2-W, 2-V fully-integrated CMOS circular-geometry active-transformer power amplifier  

Microsoft Academic Search

A 2.4-GHz, 2.2-W, 2-V fully integrated circular geometry power amplifier with 50 ? input and output matching is fabricated using 2.5 V, 0.35 ?m CMOS transistors. It can also produce 450 mW using a 1 V supply. Harmonic suppression is 64 dB or better. An on-chip circular-geometry active-transformer is used to combine several push-pull low-voltage amplifiers efficiently to produce a

Ichiro Aoki; Scott D. Kee; David Rutledge; Ali Hajimiri

2001-01-01

329

Operation of Graphene Transistors at Gigahertz Frequencies  

Microsoft Academic Search

Top-gated graphene transistors operating at high frequencies (GHz) have been fabricated and their characteristics analyzed. The measured intrinsic current gain shows an ideal 1\\/f frequency dependence, indicating an FET-like behavior for graphene transistors. The cutoff frequency fT is found to be proportional to the dc transconductance gm of the device. The peak fT increases with a reduced gate length, and

Yu-Ming Lin; Keith A. Jenkins; Alberto Valdes-Garcia; Joshua P. Small; Damon B. Farmer; Phaedon Avouris

2009-01-01

330

Ballistic carbon nanotube field-effect transistors  

Microsoft Academic Search

A common feature of the single-walled carbon-nanotube field-effect transistors fabricated to date has been the presence of a Schottky barrier at the nanotube-metal junctions. These energy barriers severely limit transistor conductance in the `ON' state, and reduce the current delivery capability-a key determinant of device performance. Here we show that contacting semiconducting single-walled nanotubes by palladium, a noble metal with

Ali Javey; Jing Guo; Qian Wang; Mark Lundstrom; Hongjie Dai

2003-01-01

331

White noise in MOS transistors and resistors  

Microsoft Academic Search

The theoretical and experimental results for white noise in the low-power subthreshold region of operation of an MOS transistor are discussed. It is shown that the measurements are consistent with the theoretical predictions. Measurements of noise in photoreceptors-circuits containing a photodiode and an MOS transistor-that are consistent with theory are reported. The photoreceptor noise measurements illustrate the intimate connection of

Rahul Sarpeshkar; T. Delbruck; Carver A. Mead

1993-01-01

332

Logic Circuits with Carbon Nanotube Transistors  

Microsoft Academic Search

We demonstrate logic circuits with field-effect transistors based on single carbon nanotubes. Our device layout features local gates that provide excellent capacitive coupling between the gate and nanotube, enabling strong electrostatic doping of the nanotube from p-doping to n-doping and the study of the nonconventional long-range screening of charge along the one-dimensional nanotubes. The transistors show favorable device characteristics such

Adrian Bachtold; Peter Hadley; Takeshi Nakanishi; Cees Dekker

2001-01-01

333

Ballistic transport in high electron mobility transistors  

Microsoft Academic Search

A general ballistic FET model that was previously used for ballistic MOSFETs is applied to ballistic high electron mobility transistors (HEMTs), and the results are compared with experimental data for a sub-50 nm InAlAs-InGaAs HEMT. The results show that nanoscale HEMTs can be modeled as an intrinsic ballistic transistor with extrinsic source\\/drain series resistances. We also examine the \\

Jing Wang; M. Lundstrom

2003-01-01

334

High frequency distortion analysis of DMOS transistors  

NASA Astrophysics Data System (ADS)

Distortion in double-diffused MOS transistors (DMOS) at high frequencies is considered in this paper. A high-frequency model, including nonlinearities, is developed for lateral double-diffused transistors (LDMOS). A complete distortion analysis, based on this model and using the Volterra Series approach, is then presented. Analytical expressions for second- and third-order intermodulation distortions are also obtained. Good agreement between first-order theory and experiment is obtained.

Sin, J. K. O.; Salama, C. A. T.

1985-12-01

335

Towards shot noise-limited detection of a single-electron transistor  

NASA Astrophysics Data System (ADS)

A Single-Electron Transistor (SET) is a highly sensitive charge amplifier based on the Coulomb blockade that can operate near the quantum limit: amplification can be accomplished with a back-action close to that required by the uncertainty principle. Its charge sensitivity is ultimately limited to about 1mue / Hz by the shot noise in the source-drain current. Despite the fact that such sensitivity has been approached by some, the shot-noise limit has yet to be reached for either the SET and its RF version, the RF-SET. A scheme is proposed and realized in this thesis for the shot noise-limited detection of a Single-Electron Transistor, based on a DC-SQUID impedance-matched with a DC-biased SET. SQUIDs can operate at the quantum limit, and a microstrip SQUID amplifier has already been demonstrated to operate at almost twice the quantum-limited noise temperature at about 500MHz by M. Muck and collaborators, with a sensitivity sufficient to resolve the SET shot noise. The device has been fabricated and characterized. A 50KO resistor has been used as a noise source at low temperature and the measured noise levels have been estimated. Moreover, the detection noise temperature of TN ? 110mK was derived corresponding to a current sensitivity of about 8fA/ Hz for the detection of a 100KO resistor.

Camarota, Benedetta

336

PAE enhancement by intermodulation cancellation in an InGaP\\/GaAs HBT two-stage power amplifier MMIC for W-CDMA  

Microsoft Academic Search

We developed an InGaP\\/GaAs heterojunction bipolar transistor (HBT) two-stage power amplifier monolithic microwave integrated circuit (MMIC) for 1.95-GHz W-CDMA. In this MMIC, intermodulation distortion (IMD) cancellation between the driver- and final-stage HBTs occurs, so we can reduce an adjacent-leakage-power-ratio (ACPR) and enhance power-added efficiency (PAE) by balancing the bias currents for each stage. The MMIC has a high PAE of

Tomohisa Hirayama; Noriaki Matsuno; Masahiro Fujii; Hikaru Hida

2001-01-01

337

IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 7, JULY 1999 277 18-GHz GaN-Based Power Amplifier  

E-print Network

IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 7, JULY 1999 277 1­8-GHz GaN-Based Power, Senior Member, IEEE Abstract-- We report the first gallium nitride (GaN)-based broad-band power amplifier. The circuit was fabricated on an AlN substrate using AlGaN/GaN power high-electron mobil- ity transistors

York, Robert A.

338

Defect Detection Differences between Launch-Off-Shift and Launch-Off-Capture in Sense-Amplifier-Based Flip-Flop Testing  

Microsoft Academic Search

About half of the logic circuit transistors of a modern integrated circuit design reside inside the scan flip-flops. Even though prior work analyzed detection of defects in traditional master-slave flip-flop circuits, to the best of our knowledge, this work is the first one regarding detection of defects in a sense-amplifier-based flip-flop, which is a preferred design style in some high-speed

Haluk Konuk

2009-01-01

339

High Performance Vertical-Type Organic Transistors And Organic Light Emitting Transistors  

Microsoft Academic Search

We have fabricated organic static induction transistor (SIT) and organic light emitting transistor (OLET) combining SIT with organic light emitting diode (OLED). SIT and OLET have a grid-type Al gate electrode that was formed using a shadow evaporation mask in the organic semiconductor layers. The effective electrode area of SIT and OLET is approximately 4 mm2. By optimizing the device

H. Endoh; S. Toguchi; K. Kudo

2007-01-01

340

Multistaged stokes injected Raman capillary waveguide amplifier  

DOEpatents

A multistaged Stokes injected Raman capillary waveguide amplifier for providing a high gain Stokes output signal. The amplifier uses a plurality of optically coupled capillary waveguide amplifiers and one or more regenerative amplifiers to increase Stokes gain to a level sufficient for power amplification. Power amplification is provided by a multifocused Raman gain cell or a large diameter capillary waveguide. An external source of CO.sub.2 laser radiation can be injected into each of the capillary waveguide amplifier stages to increase Raman gain. Devices for injecting external sources of CO.sub.2 radiation include: dichroic mirrors, prisms, gratings and Ge Brewster plates. Alternatively, the CO.sub.2 input radiation to the first stage can be coupled and amplified between successive stages.

Kurnit, Norman A. (Santa Fe, NM)

1980-01-01

341

1.3-um Raman fiber amplifier  

Microsoft Academic Search

The results of experimental research and numerical modeling of the 1.3 micrometers Raman fiber amplifier based on the high Gao2 doped fiber are presented. The Raman amplifier was pumped by the P2O5-doped fiber Raman laser. The measurements of gain and noise figure in broad range of experimental conditions are fulfilled. The amplifier gain coefficient was measured to be 42 dB\\/W.

Eugeni M. Dianov; I. A. Bufetov; Mikhail M. Bubnov; M. V. Grekov; Sergei A. Vasiliev; Oleg I. Medvedkov; A. V. Shubin; Alexei N. Guryanov; Vladimir F. Khopin; M. V. Yashkov; Evelyn M. DeLiso; D. L. Butler

2000-01-01

342

Fiber amplifiers for coherent space communication  

Microsoft Academic Search

We report on the application of double-clad doped fiber amplifiers for coherent space communication systems using a master oscillator power amplifier (MOPA) design at 1.06 ?m. The master oscillator is either a single-frequency Nd:YAG solid-state laser or a distributed-feedback fiber laser. The power amplifier is a diode-laser-pumped double-clad Nd doped fiber with polarization control, 20 dB gain, and about 1.3

Etienne Rochat; René Dändliker; Karim Haroud; Reinhard H. Czichy; Ulrich Roth; D. Costantini; Reto Holzner

2001-01-01

343

Square-Wave Analysis of Compensated Amplifiers  

Microsoft Academic Search

A complete analysis of a single-stage compensated video-frequency amplifier is presented. In this amplifier high-frequency compensation is obtained by the use of a shunt peaking coil in series with the plate load resistance, and low-frequency compensation is obtained by using a resistance-capacitance network in series with the plate load resistance. Both square-wave and sine-wave input voltages to the amplifier are

P. M. Seal

1949-01-01

344

Class E/F switching power amplifiers  

NASA Technical Reports Server (NTRS)

The present invention discloses a new family of switching amplifier classes called class E/F amplifiers. These amplifiers are generally characterized by their use of the zero-voltage-switching (ZVS) phase correction technique to eliminate of the loss normally associated with the inherent capacitance of the switching device as utilized in class-E amplifiers, together with a load network for improved voltage and current wave-shaping by presenting class-F.sup.-1 impedances at selected overtones and class-E impedances at the remaining overtones. The present invention discloses a several topologies and specific circuit implementations for achieving such performance.

Hajimiri, Seyed-Ali (Inventor); Aoki, Ichiro (Inventor); Rutledge, David B. (Inventor); Kee, Scott David (Inventor)

2004-01-01

345

Analyses of Transistor Punchthrough Failures  

NASA Technical Reports Server (NTRS)

The failure of two transistors in the Altitude Switch Assembly for the Solid Rocket Booster followed by two additional failures a year later presented a challenge to failure analysts. These devices had successfully worked for many years on numerous missions. There was no history of failures with this type of device. Extensive checks of the test procedures gave no indication for a source of the cause. The devices were manufactured more than twenty years ago and failure information on this lot date code was not readily available. External visual exam, radiography, PEID, and leak testing were performed with nominal results Electrical testing indicated nearly identical base-emitter and base-collector characteristics (both forward and reverse) with a low resistance short emitter to collector. These characteristics are indicative of a classic failure mechanism called punchthrough. In failure analysis punchthrough refers to an condition where a relatively low voltage pulse causes the device to conduct very hard producing localized areas of thermal runaway or "hot spots". At one or more of these hot spots, the excessive currents melt the silicon. Heavily doped emitter material diffuses through the base region to the collector forming a diffusion pipe shorting the emitter to base to collector. Upon cooling, an alloy junction forms between the pipe and the base region. Generally, the hot spot (punch-through site) is under the bond and no surface artifact is visible. The devices were delidded and the internal structures were examined microscopically. The gold emitter lead was melted on one device, but others had anomalies in the metallization around the in-tact emitter bonds. The SEM examination confirmed some anomalies to be cosmetic defects while other anomalies were artifacts of the punchthrough site. Subsequent to these analyses, the contractor determined that some irregular testing procedures occurred at the time of the failures heretofore unreported. These testing irregularities involved the use of a breakout box and were the likely cause of the failures. There was no evidence to suggest a generic failure mechanism was responsible for the failure of these transistors.

Nicolas, David P.

1999-01-01

346

Amplifier based broadband pixel for sub-millimeter wave imaging  

NASA Astrophysics Data System (ADS)

Broadband sub-millimeter wave technology has received significant attention for potential applications in security, medical, and military imaging. Despite theoretical advantages of reduced size, weight, and power compared to current millimeter wave systems, sub-millimeter wave systems have been hampered by a fundamental lack of amplification with sufficient gain and noise figure properties. We report a broadband pixel operating from 300 to 340 GHz, biased off a single 2 V power supply. Over this frequency range, the amplifiers provide > 40 dB gain and <8 dB noise figure, representing the current state-of-art performance capabilities. This pixel is enabled by revolutionary enhancements to indium phosphide (InP) high electron mobility transistor technology, based on a sub-50 nm gate and indium arsenide composite channel with a projected maximum oscillation frequency fmax>1.0 THz. The first sub-millimeter wave-based images using active amplification are demonstrated as part of the Joint Improvised Explosive Device Defeat Organization Longe Range Personnel Imager Program. This development and demonstration may bring to life future sub-millimeter-wave and THz applications such as solutions to brownout problems, ultra-high bandwidth satellite communication cross-links, and future planetary exploration missions.

Sarkozy, Stephen; Drewes, Jonathan; Leong, Kevin M. K. H.; Lai, Richard; Mei, X. B. (Gerry); Yoshida, Wayne; Lange, Michael D.; Lee, Jane; Deal, William R.

2012-09-01

347

The spaser as a nanoscale quantum generator and ultrafast amplifier  

NASA Astrophysics Data System (ADS)

Nanoplasmonics has recently experienced explosive development with many novel ideas and dramatic achievements in both fundamentals and applications. The spaser has been predicted and observed experimentally as an active element—a generator of coherent local fields. Even greater progress will be achieved if the spaser can function as an ultrafast nanoamplifier—an optical counterpart of the MOSFET (metal-oxide-semiconductor field effect transistor). A formidable problem with this is that the spaser has inherent feedback, causing quantum generation of nanolocalized surface plasmons and saturation and consequent elimination of the net gain, making it unsuitable for amplification. We have overcome this inherent problem and shown that the spaser can perform functions of an ultrafast nanoamplifier in two modes: transient and bistable. On the basis of quantum density matrix (optical Bloch) equations we have shown that the spaser amplifies with gain {\\gtrsim } 50 with a switching time {\\lesssim } 100 fs (potentially, ~10 fs). This prospective spaser technology will further broaden both fundamental and applied horizons of nanoscience, in particular enabling ultrafast microprocessors working at 10-100 THz clock speed. Other prospective applications are in ultrasensing, ultradense and ultrafast information storage, and biomedicine. The spasers are based on metals and, in contrast to semiconductors, are highly resistive to ionizing radiation, high temperatures, microwave radiation, and other adverse environments.

Stockman, Mark I.

2010-02-01

348

Signal-Conditioning Amplifier Recorders  

NASA Technical Reports Server (NTRS)

Signal-conditioning amplifier recorders (SCAmpRs) have been proposed as a means of simplifying and upgrading the Kennedy Space Center (KSC) Ground Measurement System (GMS), which is a versatile data-acquisition system that gathers and records a variety of measurement data before and during the launch of a space shuttle. In the present version of the GMS system, signal conditioning amplifiers digitize and transmit data to a VME chassis that multiplexes up to 416 channels. The data is transmitted via a high-speed data bus to a second VME chassis where it is available for snapshots. The data is passed from the second VME chassis to a high-speed data recorder. This process is duplicated for installations at two launch pads and the Vehicle Assembly Building (VAB). Since any failure of equipment in the data path results in loss of data, much of the system is redundant. The architecture of the existing GMS limits expansion or any modification to the system to meet changing requirements because of the cost and time required. A SCAmpR-based system is much more flexible. The basis of the simplification, flexibility, and reliability is the shifting of the recording function to the individual amplifier channels. Each SCAmpR is a self-contained single channel data acquisition system, which in its current implementation, has a data storage capacity of up to 30 minutes when operating at the fastest data sampling rates. The SCAmpR channels are self-configuring and self-calibrating. Multiple SCAmpR channels are ganged on printed circuit boards and mounted in a chassis that provides power, a network hub, and Inter-Range Instrument Group (IRIG) time signals. The SCAmpR channels share nothing except physical mounting on a circuit board. All circuitry is electrically separate for each channel. All that is necessary to complete the data acquisition system is a single master computer tied to the SCAmpR channels by standard network equipment. The size of the data acquisition system dictates the requirements for the specific network equipment.

Medelius, Pedro J.; Taylor, John

2003-01-01

349

Current gain in sub-10 nm base GaN tunneling hot electron transistors with AlN emitter barrier  

NASA Astrophysics Data System (ADS)

We report on Gallium Nitride-based tunneling hot electron transistor amplifier with common-emitter current gain greater than 1. Small signal current gain up to 5 and dc current gain of 1.3 were attained in common-emitter configuration with collector current density in excess of 50 kA/cm2. The use of a combination of 1 nm GaN/3 nm AlN layers as an emitter tunneling barrier was found to improve the energy collimation of the injected electrons. These results represent demonstration of unipolar vertical transistors in the III-nitride system that can potentially lead to higher frequency and power microwave devices.

Yang, Zhichao; Zhang, Yuewei; Nath, Digbijoy N.; Khurgin, Jacob B.; Rajan, Siddharth

2015-01-01

350

Indium foil with beryllia washer improves transistor heat dissipation  

NASA Technical Reports Server (NTRS)

Indium foil, used as an interface material in transistor mountings, greatly reduces the thermal resistance of beryllia washers. This method improves the heat dissipation of power transistors in a vacuum environment.

Hilliard, J.; John, J. E. A.

1964-01-01

351

Jig protects transistors from heat while tinning leads  

NASA Technical Reports Server (NTRS)

In tinning transistor leads, an aluminum jig is used to dip the leads into the molten tin. The jigs mass shunts excess heat given off by the molten tin before it reaches and damages the transistor body.

Pelletier, A. J.; Willis, G. A.

1966-01-01

352

All-Metallic Vertical Transistors Based on Stacked Dirac Materials  

E-print Network

It is an ongoing pursuit to use metal as a channel material in a field effect transistor. All metallic transistor can be fabricated from pristine semimetallic Dirac materials (such as graphene, silicene, and germanene), ...

Wang, Yangyang

353

Amplified spontaneous emission and Rayleigh backscattering in strongly pumped fiber amplifiers  

Microsoft Academic Search

Amplified spontaneous emission (ASE) and Rayleigh backscattering (RBS) in strongly pumped fiber amplifiers are studied, employing a rate equation model. Approximate expressions for the ASE and RES, as well as for the amplifier noise figure are derived, based on approximate analytical expressions for the amplified signal, which are valid for both three-level and four-level systems. Numerical examples for rare-earth-doped fibers,

Amos A. Hardy; Ram Oron

1998-01-01

354

Resonant isolator for maser amplifier  

NASA Technical Reports Server (NTRS)

An isolator is described for use in a low noise maser amplifier, which provides low loss across a wide bandwidth and which can be constructed at moderate cost. The isolator includes a train of garnet or ferrite elements extending along the length of a microwave channel parallel to the slow wave structure, with the elements being of staggered height, so that the thin elements which are resonant to the microwaves are separated by much thicker elements. The thick garnet or ferrite elements reduce the magnetic flux passing through the thin elements to permit altering of the shape of the thin elements so as to facilitate their fabrication and to provide better isolation with reduced loss, by increasing the thickness of the thin elements and decreasing their length and width.

Clauss, R. C.; Quinn, R. B. (inventors)

1983-01-01

355

Transverse pumped laser amplifier architecture  

DOEpatents

An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

2013-07-09

356

Development of Submillimeter SIS Mixers and Broadband HEMT Amplifiers  

NASA Technical Reports Server (NTRS)

This is the final technical report for NASA grant NAG5-9493. entitled "Development of Submillimeter SIS Mixers and Broadband HEMT Amplifiers". The goal of this project was to develop and demonstrate a new generation of superconducting tunnel junction (SIS) receivers with extremely wide instantaneous (intermediate-frequency, or IF) bandwidths. of order 12 GHz. along with the wideband low-noise microwave HEMT (high electron mobility transistor) amplifiers which follow the SIS mixer. These wideband SIS/HEMT receivers would allow rapid submillimeter wavelength spectral line surveys to be carried out, for instance with the NASA airborne observatory SOFIA. and could potentially be useful for future submillimeter space missions such as SAFIR. In addition, there are potential NASA earth science applications. such as the monitoring of the distribution of chemical species in the stratosphere and troposphere using the limb-sounding technique. The overall goals of this project have been achieved: a broadband 200-300 SIS receiver was designed and constructed, and was demonstrated in the field through a test run at the Caltech Submillimeter Observatory on Mauna Kea. HI. The technical details are described in the appendices. which are primarily conference publications. but Appendix A also includes an unpublished summary of the latest results. The work on the SIS mixer design are described in the conference publications (appendices B and C). The "Supermix" software package that was developed at Caltech and used for the SIS design is also described in two conference papers, but has been substantially revised, debugged. and extended as part of the work completed for this grant. The Supermix package is made available to the community at no charge. The electromagnetic design of a radial waveguide probe similar to the one used in this work is described in a journal publication. Details of the novel fabrication procedure used for producing the SIS devices at JPL are also given in an upcoming journal article. Finally, details on the wideband HEMT amplifier design and noise characterization techniques are described in two publications.

Zmuidzinas, J.

2004-01-01

357

Organic electrochemical transistors for cell-based impedance sensing  

NASA Astrophysics Data System (ADS)

Electrical impedance sensing of biological systems, especially cultured epithelial cell layers, is now a common technique to monitor cell motion, morphology, and cell layer/tissue integrity for high throughput toxicology screening. Existing methods to measure electrical impedance most often rely on a two electrode configuration, where low frequency signals are challenging to obtain for small devices and for tissues with high resistance, due to low current. Organic electrochemical transistors (OECTs) are conducting polymer-based devices, which have been shown to efficiently transduce and amplify low-level ionic fluxes in biological systems into electronic output signals. In this work, we combine OECT-based drain current measurements with simultaneous measurement of more traditional impedance sensing using the gate current to produce complex impedance traces, which show low error at both low and high frequencies. We apply this technique in vitro to a model epithelial tissue layer and show that the data can be fit to an equivalent circuit model yielding trans-epithelial resistance and cell layer capacitance values in agreement with literature. Importantly, the combined measurement allows for low biases across the cell layer, while still maintaining good broadband signal.

Rivnay, Jonathan; Ramuz, Marc; Leleux, Pierre; Hama, Adel; Huerta, Miriam; Owens, Roisin M.

2015-01-01

358

Graphene nanopore field effect transistors  

SciTech Connect

Graphene holds great promise for replacing conventional Si material in field effect transistors (FETs) due to its high carrier mobility. Previously proposed graphene FETs either suffer from low ON-state current resulting from constrained channel width or require complex fabrication processes for edge-defecting or doping. Here, we propose an alternative graphene FET structure created on intrinsic metallic armchair-edged graphene nanoribbons with uniform width, where the channel region is made semiconducting by drilling a pore in the interior, and the two ends of the nanoribbon act naturally as connecting electrodes. The proposed GNP-FETs have high ON-state currents due to seamless atomic interface between the channel and electrodes and are able to be created with arbitrarily wide ribbons. In addition, the performance of GNP-FETs can be tuned by varying pore size and ribbon width. As a result, their performance and fabrication process are more predictable and controllable in comparison to schemes based on edge-defects and doping. Using first-principle transport calculations, we show that GNP-FETs can achieve competitive leakage current of ?70?pA, subthreshold swing of ?60?mV/decade, and significantly improved On/Off current ratios on the order of 10{sup 5} as compared with other forms of graphene FETs.

Qiu, Wanzhi; Skafidas, Efstratios, E-mail: sskaf@unimelb.edu.au [Centre for Neural Engineering, The University of Melbourne, 203 Bouverie Street, Carlton, Victoria 3053 (Australia); Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, Victoria 3010 (Australia)

2014-07-14

359

Ambipolar phosphorene field effect transistor.  

PubMed

In this article, we demonstrate enhanced electron and hole transport in few-layer phosphorene field effect transistors (FETs) using titanium as the source/drain contact electrode and 20 nm SiO2 as the back gate dielectric. The field effect mobility values were extracted to be ?38 cm(2)/Vs for electrons and ?172 cm(2)/Vs for the holes. On the basis of our experimental data, we also comprehensively discuss how the contact resistances arising due to the Schottky barriers at the source and the drain end effect the different regime of the device characteristics and ultimately limit the ON state performance. We also propose and implement a novel technique for extracting the transport gap as well as the Schottky barrier height at the metal-phosphorene contact interface from the ambipolar transfer characteristics of the phosphorene FETs. This robust technique is applicable to any ultrathin body semiconductor which demonstrates symmetric ambipolar conduction. Finally, we demonstrate a high gain, high noise margin, chemical doping free, and fully complementary logic inverter based on ambipolar phosphorene FETs. PMID:25329532

Das, Saptarshi; Demarteau, Marcel; Roelofs, Andreas

2014-11-25

360

LASERS. AMPLIFIERS: Tunable dye laser amplifier chain for laser isotope separation  

Microsoft Academic Search

A tunable dye laser amplifier chain developed for experiments on atomic vapour laser isotope separation (AVLIS) is described. The system, pumped by copper vapour lasers, consists of a master oscillator and an amplifier stage including a preamplifier and three main amplifiers working in the saturation mode. The master oscillator of the stage is a dye laser with a grazing incidence

Igor'S. Grigoriev; Aleksei B. D'yachkov; Valerii P. Labozin; Sergei M. Mironov; Sergei A. Nikulin; Valerii A. Firsov

2004-01-01

361

Light-emitting polymer space-charge-limited transistor  

Microsoft Academic Search

Polymer light-emitting transistor is realized by vertically stacking a top-emitting polymer light-emitting diode on a polymer space-charge-limited transistor. The transistor modulates the current flow of the light-emitting diode by the metal-grid base voltage. The active semiconductor of the transistor is poly(3-hexylthiophene). Yellow poly(para-phenylene vinylene) derivative is used as the yellow emitting material. As the cathode is fixed at -12 V

Chun-Yu Chen; Yu-Chiang Chao; Hsin-Fei Meng; Sheng-Fu Horng

2008-01-01

362

Black Phosphorus Radio-Frequency Transistors  

NASA Astrophysics Data System (ADS)

Few-layer and thin film forms of layered black phosphorus (BP) have recently emerged as a promising material for applications in high performance nanoelectronics and infrared optoelectronics. Layered BP thin film offers a moderate bandgap of around 0.3 eV and high carrier mobility, leading to transistors with decent on-off ratio and high on-state current density. Here, we demonstrate the gigahertz frequency operation of black phosphorus field-effect transistors for the first time. The BP transistors demonstrated here show excellent current saturation with an on-off ratio exceeding 2000. We achieved a current density in excess of 270 mA/mm and DC transconductance above 180 mS/mm for hole conduction. Using standard high frequency characterization techniques, we measured a short-circuit current-gain cut-off frequency fT of 12 GHz and a maximum oscillation frequency fmax of 20 GHz in 300 nm channel length devices. BP devices may offer advantages over graphene transistors for high frequency electronics in terms of voltage and power gain due to the good current saturation properties arising from their finite bandgap, thus enabling the future ubiquitous transistor technology that can operate in the multi-GHz frequency range and beyond.

Wang, Han; Wang, Xiaomu; Xia, Fengnian; Wang, Luhao; Jiang, Hao; Xia, Qiangfei; Chin, Matthew L.; Dubey, Madan; Han, Shu-jen

2014-11-01

363

Self-protecting transistor oscillator for treating animal tissues  

DOEpatents

A transistor oscillator circuit wherein the load current applied to animal tissue treatment electrodes is fed back to the transistor. Removal of load is sensed to automatically remove feedback and stop oscillations. A thermistor on one treatment electrode senses temperature, and by means of a control circuit controls oscillator transistor current.

Doss, James D. (Los Alamos, NM)

1980-01-01

364

AN EFFICIENT APPROACH TO SIMULTANEOUS TRANSISTOR AND INTERCONNECT SIZING  

E-print Network

AN EFFICIENT APPROACH TO SIMULTANEOUS TRANSISTOR AND INTERCONNECT SIZING Jason Cong and Lei He study the simultaneous transistor and in- terconnect sizing (STIS) problem. We de#12;ne a class of opti-posynomial pro- grams (Theorem 1). We show that the STIS problems un- der a number of transistor delay models

Cong, Jason "Jingsheng"

365

CHARACTERISING MICROWAVE TRANSISTOR DYNAMICS WITH SMALL-SIGNAL MEASUREMENTS  

E-print Network

CHARACTERISING MICROWAVE TRANSISTOR DYNAMICS WITH SMALL-SIGNAL MEASUREMENTS Anthony E. Parker(1, Sydney AUSTRALIA 2006 mailto: jimr@ee.usyd.edu.au ABSTRACT Small-signal microwave transistor extrapolates beyond the measurement space to quantify the very significant impact that transistor dispersion

366

Chip Space and Transistor Count Estimator Marc Steinhaus  

E-print Network

Chip Space and Transistor Count Estimator Marc Steinhaus Fakultät für Informatik, Universität Karlsruhe, D-76128 Karlsruhe, Germany and RapidSolution Software GmbH, Karlsruhe General The transistor die area and the number of transistors of a simulated processor. To reach this goal, it is necessary

Ungerer, Theo

367

Buffer Minimization in Pass Transistor Logic Advanced Technology Group  

E-print Network

Buffer Minimization in Pass Transistor Logic Hai Zhou Advanced Technology Group Synopsys, Inc With the shrinking feature sizes and increasing transistor counts on chips, the push for higher speed and lower power than static CMOS. Among them, pass transistor logic (PTL) circuits give great promise. Since the delay

Zhou, Hai

368

Combined Transistor Sizing with Bu er Insertion for Timing Optimization  

E-print Network

Combined Transistor Sizing with Bu er Insertion for Timing Optimization Yanbin Jiang y Sachin S are signi - cantly better than the results given by merely using a TILOS-like transistor sizing algorithm alone. 1 Introduction The transistor sizing problem 1, 2, 3 is often formulated as Minimize Area subject

Sapatnekar, Sachin

369

Convex Delay Models for Transistor Sizing Mahesh Ketkar  

E-print Network

Convex Delay Models for Transistor Sizing Mahesh Ketkar Department of ECE, University of Minnesota for developing accurate con- vex delay models to be used for transistor sizing. A new rich class of convex for modern designs. The delay model is incorpo- rated into a transistor sizing algorithm based on TILOS

Sapatnekar, Sachin

370

Vibration-Assisted Electron Tunneling in C140 Transistors  

E-print Network

Vibration-Assisted Electron Tunneling in C140 Transistors A. N. Pasupathy, J. Park, C. Chang, A. V Karlsruhe, Germany Received August 25, 2004 ABSTRACT We measure electron tunneling in transistors made from molecules have been measured using scanning tunneling microscopes,2 single- molecule transistors,3

Sethna, James P.

371

THz Bipolar Transistor Circuits: Technical Feasibility, Technology Development,  

E-print Network

THz Bipolar Transistor Circuits: Technical Feasibility, Technology Development, Integrated Circuit Scientific Abstract--We examine the feasibility of developing bipolar transistors with current-gain and power-frequency performance limits of InP-based bipolar transistors, and their potential for operation at low THz frequencies

Rodwell, Mark J. W.

372

AC performance of nanoelectronics: towards a ballistic THz nanotube transistor  

Microsoft Academic Search

We present phenomenological predictions for the cutoff frequency of carbon nanotube transistors. We also present predictions of the effects parasitic capacitances on AC nanotube transistor performance. The influence of quantum capacitance, kinetic inductance, and ballistic transport on the high-frequency properties of nanotube transistors is analyzed. We discuss the challenges of impedance matching for ac nano-electronics in general, and show how

Peter J. Burke

2004-01-01

373

Sleep Transistor Sizing and Control for Resonant Supply Noise Damping  

E-print Network

1 Sleep Transistor Sizing and Control for Resonant Supply Noise Damping Jie Gu University that has generally been unnoticed is that sleep transistors for leakage reduction can significantly damp the resonant supply noise due to their series resistance. This paper describes an optimal sleep transistor

Kim, Chris H.

374

Sleep Transistor Sizing Using Timing Criticality and Temporal Currents  

E-print Network

Sleep Transistor Sizing Using Timing Criticality and Temporal Currents Anand Ramalingam, Bin Zhang power operation. One of the challenges in power gating is sizing the sleep transistor which is used currents to size the sleep transistor. The timing criticality information and temporal current estimation

Pan, David Z.

375

Etude du Transport dans les Transistors MOSFETs Contraints  

E-print Network

THÈSE _______________________ Etude du Transport dans les Transistors MOSFETs Contraints;tel-00436049,version1-25Nov2009 #12;RÉSUMÉ La réduction des transistors MOSFETs, briques de base des fonction de la direction du canal influence fortement les propriétés de transport des transistors MOSFETs

Paris-Sud XI, Université de

376

Bipolar-FET combinational power transistors for power conversion applications  

NASA Technical Reports Server (NTRS)

Four bipolar-FET (field-effect transistor) combinational transistor configurations are compared from the application point of view. The configurations included are FET-Darlington (cascade), emitter-open switch (cascode), parallel configuration, and FET-gated bipolar transistors (FGT).

Chen, D. Y.; Chin, S. A.

1984-01-01

377

Progress on diamond amplified photo-cathode  

Microsoft Academic Search

Two years ago, we obtained an emission gain of 40 from the Diamond Amplifier Cathode (DAC) in our test system. In our current systematic study of hydrogenation, the highest gain we registered in emission scanning was 178. We proved that our treatments for improving the diamond amplifiers are reproducible. Upcoming tests planned include testing DAC in a RF cavity. Already,

E. Wang; I. Ben-Zvi; A. Burrill; J. Kewisch; X. Chang; T. Rao; J. Smedley; Q. Wu; E. Muller; T. Xin

2011-01-01

378

Integrated-circuit balanced parametric amplifier  

NASA Technical Reports Server (NTRS)

Amplifier, fabricated on single dielectric substrate, has pair of Schottky barrier varactor diodes mounted on single semiconductor chip. Circuit includes microstrip transmission line and slot line section to conduct signals. Main features of amplifier are reduced noise output and low production cost.

Dickens, L. E.

1975-01-01

379

Method for reducing snap in magnetic amplifiers  

NASA Technical Reports Server (NTRS)

Method of reducing snap in magnetic amplifiers uses a degenerative feedback circuit consisting of a resistor and a separate winding on a magnetic core. The feedback circuit extends amplifier range by allowing it to be used at lower values of output current.

Fischer, R. L. E.; Word, J. L.

1968-01-01

380

Using Nondeterminism to Amplify Hardness Alexander Healy  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Division of Engineering revisit the problem of hardness amplification in NP, as recently studied by O'Donnell (JCSS `04). We prove to compute f on a 1/2 - 1/s (n) fraction of inputs. In particular, 1. If s(n) = n(1) , we amplify to hardness

Viola, Emanuele

381

Using Nondeterminism to Amplify Hardness Alexander Healy  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Division of Engineering revisit the problem of hardness amplification in NP, as recently studied by O'Donnell (STOC `02). We prove to compute f on a 1/2 - 1/s (n) fraction of inputs. In particular, 1. If s(n) = n(1) , we amplify to hardness

Vadhan, Salil

382

Design of a 250 GHz gyrotron amplifier  

E-print Network

A design is presented of a 250 GHz, 1 kW gyrotron traveling wave tube (gyro-TWT) amplifier with gain exceeding 50 dB. Calculations show that the amplifier will operate at 32 kV, 1 A with a saturated gain of 60 dB, an output ...

Nanni, Emilio A. (Emilio Alessandro)

2010-01-01

383

Experiment 1 A MOSFET Differential Amplifier  

E-print Network

1 EE100B Experiment 1 A MOSFET Differential Amplifier College of Engineering University of California, Riverside Objective To explore the use of MOSFETs, analog differential amplifiers and current as the current source, all implemented using MOSFETs. Equipment 2 MOSFET Arrays (MC14007UB), 5 10k resistors

Fonoberov, Vladimir

384

Power amplifier for ultrasonic transducer excitation  

Microsoft Academic Search

Design of the power amplifier for ultrasonic transducer excitation is presented. We assumed that the amplifier output impedance will be significantly lower than the transducer input impedance. Therefore we suggest to used the transformer as voltage step-up and impedance matching element. The transformer influence on the ultrasonic transducer bandwidth and the power transfer efficiency are analyzed using the Butterworth-Van Dyke

L. Svilainis

385

Diamond Amplified Photocathodes John Smedley1  

E-print Network

Diamond Amplified Photocathodes John Smedley1 , Ilan Ben-Zvi1 , Jen Bohon2 , Xiangyun Chang1 protecting the cathode from the accelerator. The amplifier is a thin diamond wafer which converts energetic. The electrons drift through the diamond under an external bias and are emitted into vacuum via a hydrogen

386

Thermoacoustic Stirling Engine --An acoustic amplifier  

E-print Network

Thermoacoustic Stirling Engine -- An acoustic amplifier: ambient heat exchanger (water) stacked screen regenerator hot heat exchanger10 kW sound 2 kW electricity 12 kW sound 10 kW sound 10 kW sound 12 amplifier: ambient heat exchanger (air) stacked screen regenerator hot heat exchanger thermosiphons

Lee, Dongwon

387

Materials physics and device development for improved efficiency of GaN HEMT high power amplifiers.  

SciTech Connect

GaN-based microwave power amplifiers have been identified as critical components in Sandia's next generation micro-Synthetic-Aperture-Radar (SAR) operating at X-band and Ku-band (10-18 GHz). To miniaturize SAR, GaN-based amplifiers are necessary to replace bulky traveling wave tubes. Specifically, for micro-SAR development, highly reliable GaN high electron mobility transistors (HEMTs), which have delivered a factor of 10 times improvement in power performance compared to GaAs, need to be developed. Despite the great promise of GaN HEMTs, problems associated with nitride materials growth currently limit gain, linearity, power-added-efficiency, reproducibility, and reliability. These material quality issues are primarily due to heteroepitaxial growth of GaN on lattice mismatched substrates. Because SiC provides the best lattice match and thermal conductivity, SiC is currently the substrate of choice for GaN-based microwave amplifiers. Obviously for GaN-based HEMTs to fully realize their tremendous promise, several challenges related to GaN heteroepitaxy on SiC must be solved. For this LDRD, we conducted a concerted effort to resolve materials issues through in-depth research on GaN/AlGaN growth on SiC. Repeatable growth processes were developed which enabled basic studies of these device layers as well as full fabrication of microwave amplifiers. Detailed studies of the GaN and AlGaN growth of SiC were conducted and techniques to measure the structural and electrical properties of the layers were developed. Problems that limit device performance were investigated, including electron traps, dislocations, the quality of semi-insulating GaN, the GaN/AlGaN interface roughness, and surface pinning of the AlGaN gate. Surface charge was reduced by developing silicon nitride passivation. Constant feedback between material properties, physical understanding, and device performance enabled rapid progress which eventually led to the successful fabrication of state of the art HEMT transistors and amplifiers.

Kurtz, Steven Ross; Follstaedt, David Martin; Wright, Alan Francis; Baca, Albert G.; Briggs, Ronald D.; Provencio, Paula Polyak; Missert, Nancy A.; Allerman, Andrew Alan; Marsh, Phil F.; Koleske, Daniel David; Lee, Stephen Roger; Shul, Randy John; Seager, Carleton Hoover; Tigges, Christopher P.

2005-12-01

388

Neodymium, erbium, and ytterbium co-doped fiber amplifier  

Microsoft Academic Search

A combination of erbium (Er), ytterbium (Yb), and neodymium (Nd), in fiber amplifiers, is examined. This combination extends the pumping wavelength spectrum by creating a new pumping path. Furthermore, the Nd addition enables pumping the amplifier from within the amplifier center, and thereby decreases the amplified spontaneous emission at the amplifier ends. A mathematical model is presented relating the excited

Itai Ron; Amos A. Hardy

2011-01-01

389

Amplified OTDR Systems for Multipoint Corrosion Monitoring  

PubMed Central

We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations. PMID:22737017

Nascimento, Jehan F.; Silva, Marcionilo J.; Coêlho, Isnaldo J. S.; Cipriano, Eliel; Martins-Filho, Joaquim F.

2012-01-01

390

Dual-range linearized transimpedance amplifier system  

SciTech Connect

A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).

Wessendorf, Kurt O. (Albuquerque, NM)

2010-11-02

391

Design and performance of the beamlet amplifiers  

SciTech Connect

In future laser systems, such as the National Ignition Facility (NIF), multi-segment amplifiers (MSAs) will be used to amplify the laser beam to the required levels. As a prototype of such a laser architecture, the authors have designed, built, and tested flash-lamp-pumped, Nd:Glass, Brewster-angle slab MSAs for the Beamlet project. In this article, they review the fundamentals of Nd:Glass amplifiers, describe the MSA geometry, discuss parameters that are important in amplifier design, and present our results on the characterization of the Beamlet MSAs. In particular, gain and beam steering measurements show that the Beamlet amplifiers meet all optical performance specifications and perform close to model predictions.

Erlandson, A.C.; Rotter, M.D.; Frank, M.D.; McCracken, R.W.

1996-06-01

392

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator were carried out before amplifier studies. The amplifier studies are postponed to the extended period after completing the parametric studies. In addition, the kinetic modeling of a solar-pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) a 10 W CW iodine laser pumped by a Vortek solar simulator; (2) kinetic modeling to predict the time to lasing threshold, lasing time, and energy output of solar-pumped iodine laser; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K. S.

1986-01-01

393

Carbon nanotube complementary wrap-gate transistors.  

PubMed

Among the challenges hindering the integration of carbon nanotube (CNT) transistors in digital technology are the lack of a scalable self-aligned gate and complementary n- and p-type devices. We report CNT transistors with self-aligned gates scaled down to 20 nm in the ideal gate-all-around geometry. Uniformity of the gate wrapping the nanotube channels is confirmed, and the process is shown not to damage the CNTs. Further, both n- and p-type transistors were realized by using the appropriate gate dielectric-HfO2 yielded n-type and Al2O3 yielded p-type-with quantum simulations used to explore the impact of important device parameters on performance. These discoveries not only provide a promising platform for further research into gate-all-around CNT devices but also demonstrate that scalable digital switches with realistic technological potential can be achieved with carbon nanotubes. PMID:23638708

Franklin, Aaron D; Koswatta, Siyuranga O; Farmer, Damon B; Smith, Joshua T; Gignac, Lynne; Breslin, Chris M; Han, Shu-Jen; Tulevski, George S; Miyazoe, Hiroyuki; Haensch, Wilfried; Tersoff, Jerry

2013-06-12

394

Symmetry-protected adiabatic quantum transistors  

E-print Network

Adiabatic quantum transistors allow quantum logic gates to be performed by applying a large field to a quantum many-body system prepared in its ground state, without the need for local control. The basic operation of such a device can be viewed as driving a spin chain from a symmetry protected phase to a trivial phase, and this perspective offers an avenue to generalise the adiabatic quantum transistor and to design several improvements. The performance of quantum logic gates is shown to depend only on universal symmetry properties of a symmetry-protected phase rather than fine tuned parent Hamiltonians, and it is possible to implement a universal set of logic gates in this way by combining several different types of symmetry protected matter. Such symmetry-protected adiabatic quantum transistors are argued to be robust to a range of relevant noise processes.

Dominic J. Williamson; Stephen D. Bartlett

2014-08-14

395

A Heteroepitaxial Perovskite Metal-Base Transistor  

SciTech Connect

'More than Moore' captures a concept for overcoming limitations in silicon electronics by incorporating new functionalities in the constituent materials. Perovskite oxides are candidates because of their vast array of physical properties in a common structure. They also enable new electronic devices based on strongly-correlated electrons. The field effect transistor and its derivatives have been the principal oxide devices investigated thus far, but another option is available in a different geometry: if the current is perpendicular to the interface, the strong internal electric fields generated at back-to-back heterojunctions can be used for oxide electronics, analogous to bipolar transistors. Here we demonstrate a perovskite heteroepitaxial metal-base transistor operating at room temperature, enabled by interface dipole engineering. Analysis of many devices quantifies the evolution from hot-electron to permeable-base behaviour. This device provides a platform for incorporating the exotic ground states of perovskite oxides, as well as novel electronic phases at their interfaces.

Yajima, T.; Hikita, Y.; /Tokyo U.; Hwang, H.Y.; /Tokyo U. /JST, PRESTO /SLAC; ,

2011-08-11

396

Transistors using crystalline silicon devices on glass  

DOEpatents

A method is disclosed for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed. 13 figs.

McCarthy, A.M.

1995-05-09

397

Nonmagnetic spin-field-effect transistor  

NASA Astrophysics Data System (ADS)

We propose a spin-field-effect transistor based on a semiconductor quantum wire with spin-orbit coupling and normal electrical contacts, instead of the ferromagnetic contacts required in the Datta and Das spin-field-effect transistor. The spin of electrons can be completely polarized and detected by manipulating and detecting the orbital wave-function using the spin-orbit coupling. The central spin-orbit coupled region consists of two segments with different strengths of Rashba spin-orbit coupling ?1 and ?2, respectively. The conductance is nearly 1 for the case of ?2=?1 and 0 for ?2=-?1 in a wide energy range. The device can work as a nonmagnetic spin transistor, which can have important applications in spintronics.

Liu, Jun-Feng; Chan, K. S.; Wang, Jun

2012-08-01

398

Superiority of p-type spin transistors  

NASA Astrophysics Data System (ADS)

The spintronic device that has probably stimulated the most research interest is the Datta-Das spin transistor. The mechanism behind it, called the Rashba effect, is that an applied voltage gives rise to a spin splitting. We demonstrate that the relevant spin splitting in k-space can be made more than three orders of magnitude larger for holes than for electrons at the same electric field. This is partly achieved by utilizing the frequently neglected lattice-mismatch between GaAs and AlGaAs. We design heterostructures where this efficient Rashba effect should show up. Compared to present transistors, we conclude that electron-based spin transistors will have problems in becoming competitive but hole-based ones are much more promising.

Gvozdic, D. M.; Ekenberg, U.

2006-09-01

399

Metal nanoparticle field-effect transistor  

NASA Astrophysics Data System (ADS)

We demonstrate that by means of a local top-gate current oscillations can be observed in extended, monolayered films assembled from monodisperse metal nanocrystals—realizing transistor function. The oscillations in this metal-based system are due to the occurrence of a Coulomb energy gap in the nanocrystals which is tunable via the nanocrystal size. The nanocrystal assembly by the Langmuir-Blodgett method yields homogeneous monolayered films over vast areas. The dielectric oxide layer protects the metal nanocrystal field-effect transistors from oxidation and leads to stable function for months. The transistor function can be reached due to the high monodispersity of the nanocrystals and the high super-crystallinity of the assembled films. Due to the fact that the film consists of only one monolayer of nanocrystals and all nanocrystals are simultaneously in the state of Coulomb blockade the energy levels can be influenced efficiently (limited screening).

Cai, Yuxue; Michels, Jan; Bachmann, Julien; Klinke, Christian

2013-07-01

400

Thin Film Transistors On Plastic Substrates  

DOEpatents

A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The silicon based thin film transistor produced by the process includes a low temperature substrate incapable of withstanding sustained processing temperatures greater than about 250.degree. C., an insulating layer on the substrate, a layer of silicon on the insulating layer having sections of doped silicon, undoped silicon, and poly-silicon, a gate dielectric layer on the layer of silicon, a layer of gate metal on the dielectric layer, a layer of oxide on sections of the layer of silicon and the layer of gate metal, and metal contacts on sections of the layer of silicon and layer of gate metal defining source, gate, and drain contacts, and interconnects.

Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Ramon, CA); Sigmon, Thomas W. (Portola Valley, CA); Aceves, Randy C. (Livermore, CA)

2004-01-20

401

The Microstrip SQUID Amplifier: Upgrading the Axion Dark Matter Experiment (ADMX)  

NASA Astrophysics Data System (ADS)

The axion detector, now at the University of Washington, Seattle. requires a very low noise amplifier in the 1-GHz frequency range. In the first generation detector, the cavity was cooled to 1.5 K and used a HEMT (High Electron Mobility Transistor) amplifier with a noise temperature TN of 1.7 K. Thus, the system noise temperature TS was 3.2 K. To achieve significantly lower noise temperatures, we developed the Microstrip SQUID Amplifier (MSA) in which the input coil forms a microstrip with the SQUID washer. When the length of the coil corresponds to a half-wavelength of the signal, the gain is typically 20 dB. We measured the gain and noise of an MSA at 0.62 GHz, and achieved a minimum noise temperature TN= 48 ±5 mK for a bath temperature of 50 mK and at a frequency slightly below resonance, as predicted. The quantum limit is 30 mK. Since the time for the axion detector to scan a given frequency range scales as TS^2, replacing the HEMT with a SQUID and cooling the cavity to 50 mK potentially reduces the scan time by three orders of magnitude. In a proof-of-principle run, the system was operated at 1.7 K with an MSA readout, and performed as predicted. A total of 88,370, 80-second data sets were acquired, corresponding to 82 days of data acquisition.

Clarke, John; Kinion, Darin

2011-11-01

402

Solid state power amplifier as 805 MHz master source for the LANSCE coupled-cavity linac  

SciTech Connect

From 100 to 800 MeV, the Los Alamos Neutron Science Center (LANSCE) proton linac receives RF power from forty-four 1.25 MW klystrons at 805 Megahertz (MHz). A single master RF source provides a continuous high level phase reference signal which drives the klystrons along the 731 meter-long linac through a coaxial transmission line. A single point failure of this system can deenergize the entire coupled-cavity linac (CCL) RF plant. The authors replaced a physically large air-cooled tetrode amplifier with a compact water-cooled unit based on modular amplifier pallets developed at LANSCE. Each 600 Watt pallet utilizes eight push-pull bipolar power transistor pairs operated in class AB. Four of these can easily provide the 2000 watt reference carrier from the stable master RF source. A radial splitter and combiner parallels the modules. This amplifier has proven to be completely reliable after two years of operation without failure. A second unit was constructed and installed for redundancy, and the old tetrode system was removed in 1998. The compact packaging for cooling, DC power, impedance matching, RF interconnection, and power combining met the electrical and mechanical requirements. CRT display of individual collector currents and RF levels is made possible with built-in samplers and a VXI data acquisition unit.

Lyles, J.; Davis, J.

1998-12-31

403

A 2.3-GHz low-noise cryo-FET amplifier  

NASA Technical Reports Server (NTRS)

A cryogenic cooled, low-noise Field Effect Transistor (FET) amplifier assembly for use at 2.2 to 2.3 GHz was developed for the DSN to meet the requirements of a Very Long Baseline Interferometry (VLBI) upgrade. An amplifier assembly was developed at JPL that uses a commercial closed-cycle helium refrigerator (CCR) to cool a FET amplifier to an operating temperature of 15 K. A cooled probe waveguide-to-coaxial transition similar to that used in the research and development Ultra-Low-Noise S-band Traveling Wave Maser (TWM) is used to minimize input line losses. Typical performance includes an input flange equivalent noise contribution of 14.5 K, a gain slope of less than 0.05 dB/MHz across a bandwidth of 2.2 to 2.3 GHz, an input VSWR of 1.5:1 at 2.25 GHz, and an insertion gain of 45 + or - 1 dB across the bandwidth of 2.2 to 2.3 GHz. Three 2.3 GHz FET/CCR assemblies were delivered to the DSN in the spring of 1987.

Loreman, J.

1988-01-01

404

Logic circuit function realization by one transistor.  

PubMed

Bottom-up nanowires are very attractive building blocks for functional devices due to their controllable properties. Meanwhile, assembling nanowires into large-scale integrated circuits is a daunting challenge because for the present circuits diverse nanowires are needed to grow simultaneously together closely. Here, a nanowire trigate transistor structure is proposed which can accomplish the functions of the logic gate circuits. By adding one channel-electrode junction as the output, this interesting one-channel structure is used to realize inverter and OR logic gates. In this way, logic circuits could shrink into a single transistor. PMID:23075033

Dai, Mingzhi; Dai, Ning

2012-11-14

405

Total Dose Effects in Conventional Bipolar Transistors  

NASA Technical Reports Server (NTRS)

This paper examines various factors in bipolar device construction and design, and discusses their impact on radiation hardness. The intent of the paper is to improve understanding of the underlying mechanisms for practical devices without special test structures, and to provide (1) guidance in ways to select transistor designs that are more resistant to radiation damage, and (2) methods to estimate the maximum amount of damage that might be expected from a basic transistor design. The latter factor is extremely important in assessing the risk that future lots of devices will be substantially below design limits, which are usually based on test data for older devices.

Johnston, A. H.; Swift, G. W.; Rax, B. G.

1994-01-01

406

p-type metal-base transistor  

NASA Astrophysics Data System (ADS)

In this work we present data from a novel p-type metal-base transistor with common-base gain ? ˜1, fabricated at ambient temperature and pressure by electrodepositing sequentially on a p-type Si collector, a Co base and a Cu2O emitter. The high gain and the dependence of potential between emitter and base (VEB) on the potential between collector and base (VCB) when the emitter current (IE) is held constant both suggest that the device functions as a natural permeable base transistor for very thin metal bases.

Delatorre, R. G.; Munford, M. L.; Zandonay, R.; Zoldan, V. C.; Pasa, A. A.; Schwarzacher, W.; Meruvia, M. S.; Hümmelgen, I. A.

2006-06-01

407

Static Characteristics of the Ferroelectric Transistor Inverter  

NASA Technical Reports Server (NTRS)

The inverter is one of the most fundamental building blocks of digital logic, and it can be used as the foundation for understanding more complex logic gates and circuits. This paper presents the characteristics of an inverter circuit using a ferroelectric field-effect transistor. The voltage transfer characteristics are analyzed with respect to varying parameters such as supply voltage, input voltage, and load resistance. The effects of the ferroelectric layer between the gate and semiconductor are examined, and comparisons are made between the inverters using ferroelectric transistors and those using traditional MOSFETs.

Mitchell, Cody; Laws, crystal; MacLeond, Todd C.; Ho, Fat D.

2010-01-01

408

Switching Characteristics of Ferroelectric Transistor Inverters  

NASA Technical Reports Server (NTRS)

This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, phl and plh are presented along with the output voltage rise and fall times, rise and fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times are the times required for the output voltages to transition between the voltage levels V10% and V90%. Comparisons are made between the MOSFET inverter and the ferroelectric transistor inverter.

Laws, Crystal; Mitchell, Coey; MacLeod, Todd C.; Ho, Fat D.

2010-01-01

409

Angle dependent conductivity in graphene FET transistors  

NASA Astrophysics Data System (ADS)

In this work we analyze a model of conductance across a field effect transistor built of monolayer graphene. We show how a top gate voltage non-perpendicular to the source-drain direction creates an effective gap in pristine graphene devices. We have studied several scenarios in order to model the presence of inhomogeneities in the graphene and its influence in the creation of an effective gap showing that it is a robust effect. Moreover, although the gap appears for any angle of the top-gate, tuning the FET parameters we achieve noticeable on-off ratios overcoming one of the main difficulties of graphene transistors.

Fuentevilla, C. H.; Lejarreta, J. D.; Cobaleda, C.; Diez, E.

2015-02-01

410

High fidelity readout of a transmon qubit using a superconducting low-inductance undulatory galvanometer microwave amplifier  

NASA Astrophysics Data System (ADS)

We report high-fidelity, quantum non-demolition, single-shot readout of a superconducting transmon qubit using a dc-biased superconducting low-inductance undulatory galvanometer (SLUG) amplifier. The SLUG improves the system signal-to-noise ratio by 6.5 dB in a 20 MHz window compared with a bare high electron mobility transistor amplifier. An optimal cavity drive pulse is chosen using a genetic search algorithm, leading to a maximum combined readout and preparation fidelity of 91.9% with a measurement time of {{T}meas}=200 ns. Using post-selection to remove preparation errors caused by heating, we realize a combined preparation and readout fidelity of 94.3%.

Liu, Yanbing; Srinivasan, Srikanth J.; Hover, D.; Zhu, Shaojiang; McDermott, R.; Houck, A. A.

2014-11-01

411

Techniques for high-efficiency outphasing power amplifiers  

E-print Network

A trade-off between linearity and efficiency exists in conventional power amplifiers (PAs). The outphase amplifying concept overcomes this trade-off by enabling the use of high efficiency, non-linear power amplifiers for ...

Godoy, Philip (Philip Andrew)

2011-01-01

412

Ph 315 Lab Notes A. La Rosa OPERATIONAL AMPLIFIERS  

E-print Network

Ph 315 Lab Notes A. La Rosa OPERATIONAL AMPLIFIERS ___________________________________________________________ 1. THE ROLE OF OPERATIONAL AMPLIFIERS A typical digital data acquisition system uses a transducer or microcontroller (volts). A conditioning circuit composed of operational amplifiers is then use for that purpose

413

PH-315 Lab Notes A. La Rosa OPERATIONAL AMPLIFIERS  

E-print Network

PH-315 Lab Notes A. La Rosa OPERATIONAL AMPLIFIERS ___________________________________________________________ 1. THE ROLE OF OPERATIONAL AMPLIFIERS A typical digital data acquisition system uses a transducer or microcontroller (volts). A conditioning circuit composed of operational amplifiers is then use for that purpose

La Rosa, Andres H.

414

Galen Sasaki University of Hawaii 1 Optical Amplifiers  

E-print Network

1 Galen Sasaki University of Hawaii 1 Components · Optical Amplifiers ­ Semiconductor Optical Amplifiers (SOAs) · Transmitters ­ Lasers ­ External Cavity Lasers ­ Tunable Lasers ­ Vertical Cavity Surface Emitting Lasers ­ LEDs Galen Sasaki University of Hawaii 2 Outline · Optical Amplifiers ­ Semiconductor

Sasaki, Galen H.

415

Neodymium, erbium, and ytterbium co-doped fiber amplifier  

NASA Astrophysics Data System (ADS)

A combination of erbium (Er), ytterbium (Yb), and neodymium (Nd), in fiber amplifiers, is examined. This combination extends the pumping wavelength spectrum by creating a new pumping path. Furthermore, the Nd addition enables pumping the amplifier from within the amplifier center, and thereby decreases the amplified spontaneous emission at the amplifier ends. A mathematical model is presented relating the excited population density, the signal power along the amplifier, the energy transfer among the ions, and the amplified spontaneous emissions. The study compares the amplifier characteristics of Er-Yb-Nd co-doped amplifier with a traditional Er-Yb amplifier for various combinations. The new configuration adds flexibility into the amplifier design. By properly selecting its parameters, one can increase the output signal power and decrease the amplified spontaneous emission, to comply with various requirements.

Ron, Itai; Hardy, Amos A.

2011-07-01

416

Ultrafast disk lasers and amplifiers  

NASA Astrophysics Data System (ADS)

Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

2012-03-01

417

Multi-pass light amplifier  

NASA Technical Reports Server (NTRS)

A multiple-pass laser amplifier that uses optical focusing between subsequent passes through a single gain medium so that a reproducibly stable beam size is achieved within the gain region. A confocal resonator or White Cell resonator is provided, including two or three curvilinearly shaped mirrors facing each other along a resonator axis and an optical gain medium positioned on the resonator axis between the mirrors (confocal resonator) or adjacent to one of the mirrors (White Cell). In a first embodiment, two mirrors, which may include adjacent lenses, are configured so that a light beam passing through the gain medium and incident on the first mirror is reflected by that mirror toward the second mirror in a direction approximately parallel to the resonator axis. A light beam translator, such as an optical flat of transparent material, is positioned to translate this light beam by a controllable amount toward or away from the resonator axis for each pass of the light beam through the translator. The optical gain medium may be solid-state, liquid or gaseous medium and may be pumped longitudinally or transversely. In a second embodiment, first and second mirrors face a third mirror in a White Cell configuration, and the optical gain medium is positioned at or adjacent to one of the mirrors. Defocusing means and optical gain medium cooling means are optionally provided with either embodiment, to controllably defocus the light beam, to cool the optical gain medium and to suppress thermal lensing in the gain medium.

Plaessmann, Henry (Inventor); Grossman, William M. (Inventor)

1997-01-01

418

Progress on diamond amplified photo-cathode  

SciTech Connect

Two years ago, we obtained an emission gain of 40 from the Diamond Amplifier Cathode (DAC) in our test system. In our current systematic study of hydrogenation, the highest gain we registered in emission scanning was 178. We proved that our treatments for improving the diamond amplifiers are reproducible. Upcoming tests planned include testing DAC in a RF cavity. Already, we have designed a system for these tests using our 112 MHz superconducting cavity, wherein we will measure DAC parameters, such as the limit, if any, on emission current density, the bunch charge, and the bunch length. The diamond-amplified photocathode, that promises to support a high average current, low emittance, and a highly stable electron beam with a long lifetime, is under development for an electron source. The diamond, functioning as a secondary emitter amplifies the primary current, with a few KeV energy, that comes from the traditional cathode. Earlier, our group recorded a maximum gain of 40 in the secondary electron emission from a diamond amplifier. In this article, we detail our optimization of the hydrogenation process for a diamond amplifier that resulted in a stable emission gain of 140. We proved that these characteristics are reproducible. We now are designing a system to test the diamond amplifier cathode using an 112MHz SRF gun to measure the limits of the emission current's density, and on the bunch charge and bunch length.

Wang, E.; Ben-Zvi, I.; Burrill, A.; Kewisch, J.; Chang, X.; Rao, T.; Smedley, J.; Wu, Q.; Muller, E.; Xin, T.

2011-03-28

419

Single mode terahertz quantum cascade amplifier  

NASA Astrophysics Data System (ADS)

A terahertz (THz) optical amplifier based on a 2.9 THz quantum cascade laser (QCL) structure has been demonstrated. By depositing an antireflective coating on the QCL facet, the laser mirror losses are enhanced to fully suppress the lasing action, creating a THz quantum cascade (QC) amplifier. Terahertz radiation amplification has been obtained, by coupling a separate multi-mode THz QCL of the same active region design to the QC amplifier. A bare cavity gain is achieved and shows excellent agreement with the lasing spectrum from the original QCL without the antireflective coating. Furthermore, a maximum optical gain of ˜30 dB with single-mode radiation output is demonstrated.

Ren, Y.; Wallis, R.; Shah, Y. D.; Jessop, D. S.; Degl'Innocenti, R.; Klimont, A.; Kamboj, V.; Beere, H. E.; Ritchie, D. A.

2014-10-01

420

Phase noise in RF and microwave amplifiers.  

PubMed

Understanding amplifier phase noise is a critical issue in many fields of engineering and physics, such as oscillators, frequency synthesis, telecommunication, radar, and spectroscopy; in the emerging domain of microwave photonics; and in exotic fields, such as radio astronomy, particle accelerators, etc. Focusing on the two main types of base noise in amplifiers, white and flicker, the power spectral density of the random phase ?(t) is S?(f) = b(0) + b(-1)/f. White phase noise results from adding white noise to the RF spectrum in the carrier region. For a given RF noise level, b(0) is proportional to the reciprocal of the carrier power P(0). By contrast, flicker results from a near-dc 1/f noise-present in all electronic devices-which modulates the carrier through some parametric effect in the semiconductor. Thus, b(-1) is a parameter of the amplifier, constant in a wide range of P(0). The consequences are the following: Connecting m equal amplifiers in parallel, b(-1) is 1/m times that of one device. Cascading m equal amplifiers, b(-1) is m times that of one amplifier. Recirculating the signal in an amplifier so that the gain increases by a power of m (a factor of m in decibels) as a result of positive feedback (regeneration), we find that b(-1) is m(2) times that of the amplifier alone. The feedforward amplifier exhibits extremely low b(-1) because the carrier is ideally nulled at the input of its internal error amplifier. Starting with an extensive review of the literature, this article introduces a system-oriented model which describes the phase flickering. Several amplifier architectures (cascaded, parallel, etc.) are analyzed systematically, deriving the phase noise from the general model. There follow numerous measurements of amplifiers using different technologies, including some old samples, and in a wide frequency range (HF to microwaves), which validate the theory. In turn, theory and results provide design guidelines and give suggestions for CAD and simulation. To conclude, this article is intended as a tutorial, a review, and a systematic treatise on the subject, supported by extensive experiments. PMID:23221210

Boudot, Rodolphe; Rubiola, Enrico

2012-12-01

421

Diode amplifier of modulated optical beam power  

NASA Astrophysics Data System (ADS)

Analytical relations are obtained between characteristics of modulated light at the output and input of an optical diode power amplifier operating in the highly saturated gain regime. It is shown that a diode amplifier may act as an amplitude-to-phase modulation converter with a rather large bandwidth (~10 GHz). The low sensitivity of the output power of the amplifier to the input beam power and its high energy efficiency allow it to be used as a building block of a high-power multielement laser system with coherent summation of a large number of optical beams.

D'yachkov, N. V.; Bogatov, A. P.; Gushchik, T. I.; Drakin, A. E.

2014-11-01

422

Phase-stable, microwave FEL amplifier  

SciTech Connect

Free-electron laser (FEL) amplifiers have demonstrated high efficiency and high output power for microwave wavelengths. However, using present technology, microwave FEL amplifiers are not phase stable enough to be suitable for driving linear accelerators, where several much amplifiers need to be phase locked. The growing wave`s phase sensitivity to the beam voltage in the small-signal gain regime is responsible for the largest contribution to this phase instability. We discuss a scheme that reduces the phase sensitivity to the beam voltage by operating off synchronism and matching the phase variation resulting from the desynchronism to the phase variation from the reduced plasma wavenumber as the beam voltage changes.

Carlsten, B.E.; Fazio, M.V.; Haynes, W.B.; May, L. [Los Alamos National Lab., NM (United States); Potter, M. [JP Accelerator Works, Inc., Los Alamos, NM (United States)

1995-07-01

423

COOPER PAIR TRANSISTOR IN A TUNABLE ENVIRONMENT  

E-print Network

COOPER PAIR TRANSISTOR IN A TUNABLE ENVIRONMENT S. Corlevi, W. Guichard, and D. B. Haviland* 1 measurements of the CPT, which are performed in a low impedance environment, the charging effects are observed as gate voltage modulation of the critical current. However, in a high impedance environment, a Coulomb

Haviland, David

424

Current and Charge Control in Molecular Transistors  

NASA Astrophysics Data System (ADS)

In a simple, conceptual model for a molecular transistor current and charge control mechanisms analogous to that of a conventional ballistic field effect transistor were assumed, where the molecular levels are translated with respect to source and drain Fermi levels by the self-consistent potential in the center of the molecule resulting from the gate, source and drain voltages and the internal `space' charge. It was also shown that a single resonant level is inadequate for achieving a large on-off ratio concomitant with high performance, leading to the concept of using molecules to design an electronic filter. The assumptions of this model were tested by the present authors using a model `biphenyl' molecular transistor, and self-consistently solving Schrödinger's and Poisson's equations within the density-functional formalism. While some gross features of the simple model were preserved, other types of behavior were completely unexpected, such as the observation of non-monotonic potential progression with a monotonically increasing gate voltage. In contrast to the simple model, polarization of levels well below the Fermi level dominated the charge control. This new, complex and interesting behavior will be discussed along with its bearing on the molecular transistor as a logic element.

Solomon, Paul

2005-03-01

425

Characterizing charge trapping in microwave transistors  

Microsoft Academic Search

This paper looks at the problems associated with pulsed testing of GaN and GaAs HEMTs and its use in examining the charging and discharging times of the various traps that affect conduction. A particular problem is that the RF behaviour of these transistors varies with the state of charge of the traps. This is a concern for a large class

James G. Rathmell; Anthony E. Parker

426

Thermal properties of very fast transistors  

Microsoft Academic Search

Recent predictions that thermal effects will limit future transistor speed improvement motivated an interest in predicting and measuring these effects. A mathematical model of the three-dimensional transient heat flow problem is presented which takes into account the physical structure of the device and the actual region of power dissipation. At any point within the device, the model predicts the time-dependent

R. C. Joy; E. S. Schlig

1970-01-01

427

Radiation Tolerance of 65nm CMOS Transistors  

E-print Network

We report on the effects of ionizing radiation on 65nm CMOS transistors held at approximately -20C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.

Krohn, M; Cumalat, J P; Wagner, S R; Christian, D C; Deptuch, G; Fahim, F; Hoff, J; Shenai, A

2015-01-01

428

Radiation Tolerance of 65nm CMOS Transistors  

E-print Network

We report on the effects of ionizing radiation on 65nm CMOS transistors held at approximately -20C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.

M. Krohn; B. Bentele; J. P. Cumalat; S. R. Wagner; D. C. Christian; G. Deptuch; F. Fahim; J. Hoff; A. Shenai

2015-01-23

429

MOS transistor modeling for RF IC design  

Microsoft Academic Search

This paper presents the basis of the modeling of the MOS transistor for circuit simulation at RF. A physical equivalent circuit that can easily be implemented as a Spice subcircuit is first derived. The subcircuit includes a substrate network that accounts for the signal coupling occurring at HF from the drain to the source and the bulk. It is shown

Christian C. Enz; Yuhua Cheng

2000-01-01

430

Heterostructure bipolar transistors and integrated circuits  

Microsoft Academic Search

A bipolar transmitter with a wide-gap emitter is presented. Examples of heterostructure implementations of IIL and ECL are discussed, and future device possibilities based on technological premises are considered. The concept and high-speed benefits of the widegap emitter are reviewed, including recent conceptual developments such as an inverted transistor design in which the collector is made smaller than the emitter

HERBERT KROEMER

1982-01-01

431

Black phosphorus radio-frequency transistors.  

PubMed

Few-layer and thin film forms of layered black phosphorus (BP) have recently emerged as a promising material for applications in high performance nanoelectronics and infrared optoelectronics. Layered BP thin films offer a moderate bandgap of around 0.3 eV and high carrier mobility, which lead to transistors with decent on-off ratios and high on-state current densities. Here, we demonstrate the gigahertz frequency operation of BP field-effect transistors for the first time. The BP transistors demonstrated here show respectable current saturation with an on-off ratio that exceeds 2 × 10(3). We achieved a current density in excess of 270 mA/mm and DC transconductance above 180 mS/mm for hole conduction. Using standard high frequency characterization techniques, we measured a short-circuit current-gain cutoff frequency fT of 12 GHz and a maximum oscillation frequency fmax of 20 GHz in 300 nm channel length devices. BP devices may offer advantages over graphene transistors for high frequency electronics in terms of voltage and power gain due to the good current saturation properties arising from their finite bandgap, thus can be considered as a promising candidate for the future high performance thin film electronics technology for operation in the multi-GHz frequency range and beyond. PMID:25347787

Wang, Han; Wang, Xiaomu; Xia, Fengnian; Wang, Luhao; Jiang, Hao; Xia, Qiangfei; Chin, Matthew L; Dubey, Madan; Han, Shu-jen

2014-11-12

432

High Performance Electrolyte Gated Carbon Nanotube Transistors  

Microsoft Academic Search

We have fabricated high performance field-effect transistors made from semiconducting single-walled carbon nanotubes (SWNTs). Using chemical vapor deposition to grow the tubes, annealing to improve the contacts, and an electrolyte as a gate, we obtain very high device mobilites and transconductances. These measurements demonstrate that SWNTs are attractive for both electronic applications and for chemical and biological sensing.

Sami Rosenblatt; Yuval Yaish; Jiwoong Park; Jeff Gore; Vera Sazonova; Paul L. McEuen

2002-01-01

433

Thermal simulation techniques for nanoscale transistors  

Microsoft Academic Search

Thermal simulations are important for advanced electronic sys- tems at multiple length scales. A major challenge involves electro- thermal phenomena within nanoscale transistors, which exhibit nearly ballistic transport both for electrons and phonons. The ther- mal device behavior can influence both the mobility and the leakage currents. We discuss recent advances in modeling coupled electron- phonon transport in future nanoscale

Jeremy A. Rowlette; Eric Pop; Sanjiv Sinha; Mathew Panzer; Kenneth E. Goodson

2005-01-01

434

Gallium nitride junction field-effect transistor  

DOEpatents

An all-ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorous co-implantation, in selected III-V semiconductor materials.

Zolper, John C. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM)

1999-01-01

435

Gallium nitride junction field-effect transistor  

DOEpatents

An ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same are disclosed. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorus co-implantation, in selected III-V semiconductor materials. 19 figs.

Zolper, J.C.; Shul, R.J.

1999-02-02

436

Double diffused high speed Ge transistors  

Microsoft Academic Search

The recent progress on pyrolytic deposition of masking films on semiconductor surfaces allows one to adopt double diffused technologies for Ge similar to that used for Si. Because of the more favorable material properties, Ge offers the possibility of higher speed and frequency devices. This paper describes the process of double diffused npn and npn planar transistors. The lateral dimensions

P. Gansauge

1967-01-01

437

High Performance Electrolyte Gated Carbon Nanotube Transistors  

E-print Network

, Jiwoong Park,, Jeff Gore, Vera Sazonova, and Paul L. McEuen*, Laboratory of Atomic and Solid State PhysicsHigh Performance Electrolyte Gated Carbon Nanotube Transistors Sami Rosenblatt, Yuval Yaish to grow the tubes, annealing to improve the contacts, and an electrolyte as a gate, we obtain very high

Gore, Jeff

438

Water-gel for gating graphene transistors.  

PubMed

Water, the primary electrolyte in biology, attracts significant interest as an electrolyte-type dielectric material for transistors compatible with biological systems. Unfortunately, the fluidic nature and low ionic conductivity of water prevents its practical usage in such applications. Here, we describe the development of a solid state, megahertz-operating, water-based gate dielectric system for operating graphene transistors. The new electrolyte systems were prepared by dissolving metal-substituted DNA polyelectrolytes into water. The addition of these biocompatible polyelectrolytes induced hydrogelation to provide solid-state integrity to the system. They also enhanced the ionic conductivities of the electrolytes, which in turn led to the quick formation of an electric double layer at the graphene/electrolyte interface that is beneficial for modulating currents in graphene transistors at high frequencies. At the optimized conditions, the Na-DNA water-gel-gated flexible transistors and inverters were operated at frequencies above 1 MHz and 100 kHz, respectively. PMID:24773325

Kim, Beom Joon; Um, Soong Ho; Song, Woo Chul; Kim, Yong Ho; Kang, Moon Sung; Cho, Jeong Ho

2014-05-14

439

Ku band low noise parametric amplifier  

NASA Technical Reports Server (NTRS)

A low noise, K sub u-band, parametric amplifier (paramp) was developed. The unit is a spacecraft-qualifiable, prototype, parametric amplifier for eventual application in the shuttle orbiter. The amplifier was required to have a noise temperature of less than 150 K. A noise temperature of less than 120 K at a gain level of 17 db was achieved. A 3-db bandwidth in excess of 350 MHz was attained, while deviation from phase linearity of about + or - 1 degree over 50 MHz was achieved. The paramp operates within specification over an ambient temperature range of -5 C to +50 C. The performance requirements and the operation of the K sub u-band parametric amplifier system are described. The final test results are also given.

1976-01-01

440

Hybrid waveguides for optically pumped amplifiers  

E-print Network

A hybrid waveguide based on simultaneous propagation of photonic crystal (PC) and total internal reflection confined optical modes is introduced for a scheme to uniformly pump waveguide optical amplifiers (WOAs). Planar ...

Saini, S.

441

Microwave diode amplifiers with low intermodulation distortion  

NASA Technical Reports Server (NTRS)

Distortions can be greatly reduced in narrow-band applications by using the second harmonic. The ac behavior of simplified diode amplifier has negative resistance depending on slope of equivalent I-V curve.

Cooper, H. W.; Cohn, M.; Buck, D. C.

1975-01-01

442

Advanced Concepts in Josephson Junction Reflection Amplifiers  

NASA Astrophysics Data System (ADS)

Low-noise amplification at microwave frequencies has become increasingly important for the research related to superconducting qubits and nanoelectromechanical systems. The fundamental limit of added noise by a phase-preserving amplifier is the standard quantum limit, often expressed as noise temperature . Towards the goal of the quantum limit, we have developed an amplifier based on intrinsic negative resistance of a selectively damped Josephson junction. Here we present measurement results on previously proposed wide-band microwave amplification and discuss the challenges for improvements on the existing designs. We have also studied flux-pumped metamaterial-based parametric amplifiers, whose operating frequency can be widely tuned by external DC-flux, and demonstrate operation at pumping, in contrast to the typical metamaterial amplifiers pumped via signal lines at.

Lähteenmäki, Pasi; Vesterinen, Visa; Hassel, Juha; Paraoanu, G. S.; Seppä, Heikki; Hakonen, Pertti

2014-06-01

443

A DC stabilized fully differential amplifier  

E-print Network

The conventional method of constructing a gain amplifier is to use resistor feedback networks. However, present CMOS technology provides capacitors that offer substantially better tracking and linearity performance over ...

Sun, Nancy Y

2005-01-01

444

Mechanical Amplifier for Translational Kinetic Energy Harvesters  

NASA Astrophysics Data System (ADS)

This paper reports the design, optimization, and test results of a mechanical amplifier coupled to an electromagnetic energy harvester to generate power from low- amplitude (±1 mm) and low-frequency (<5 Hz) vibrations in the presence of large static displacements. When coupled to a translational kinetic energy harvester, the amplifier boosts small vibration amplitudes by as much as 4x while accommodating translational displacements of more than 10x of vibration amplitudes. A complete electromagnetic energy harvester using this mechanical amplifier produces 16x improvement in output power (30 mW vs 1.9 mW without amplifier at 5 Hz), and a high power density of 170 ?W/cm3.

Shahosseini, I.; Najafi, K.

2014-11-01

445

Sensor/amplifier for weak light sources  

NASA Technical Reports Server (NTRS)

Light sensor/amplifier circuit detects weak light converts it into strong electrical signal in electrically noisy environment. Circuit is relatively simple and uses inexpensive, readily available components. Device is useful in such applications as fire detection and photographic processing.

Desmet, D. J.; Jason, A. J.; Parr, A. C.

1980-01-01

446

Increasing dynamic range in microwave parametric amplifiers  

NASA Astrophysics Data System (ADS)

Parametric amplifiers have long been of interest in quantum information due to their high gain and near quantum limited performance. In collaboration with UC Berkeley, we are improving upon their proven parametric amplifier design, which consists of a lumped element LC resonator, with a SQUID providing a tunable nonlinear inductance. In order to improve the dynamic range of these amplifiers, multiple SQUIDs are used in series in order to distribute the non-linearity across many junctions. We report on the design of a single-ended amplifier using our 7-layer fabrication process, combining photo and electron beam lithography. We explore the experimental optimization of such a design, specifically the impact of adding additional SQUIDs on overall device performance.

Mutus, J.; Barends, R.; Bochmann, J.; Campbell, B.; Chen, Y.; Chiaro, B.; Jeffrey, E.; Kelly, J.; Mariantoni, M.; Megrant, A.; Neill, C.; O'Malley, P.; Ohya, S.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T.; Cleland, A. N.; Martinis, J. M.

2013-03-01

447

A novel wideband gyrotron travelling wave amplifier  

E-print Network

We present the design and the experimental results of a novel wideband quasioptical Gyrotron Traveling Wave Tube (gyro-TWT) amplifier and the first Vacuum Electron Device (VED) with a Photonic Band Gap (PBG) structure. The ...

Sirigiri, Jagadishwar R. (Jagadishwar Rao), 1973-

2003-01-01

448

How to characterize the nonlinear amplifier?  

NASA Technical Reports Server (NTRS)

The conception of the amplification of the coherent field is formulated. The definition of the coefficient of the amplification as the relation between the mean value of the field at the output to the value at the input and the definition of the noise as the difference between the number of photons in the output mode and square of the modulus of the mean value of the output amplitude are considered. Using a simple example it is shown that by these definitions the noise of the nonlinear amplifier may be less than the noise of the ideal linear amplifier of the same amplification coefficient. Proposals to search another definition of basic parameters of the nonlinear amplifiers are discussed. This definition should enable us to formulate the universal fundamental lower limit of the noise which should be valid for linear quantum amplifiers as for nonlinear ones.

Kallistratova, Dmitri Kouznetsov; Cotera, Carlos Flores

1994-01-01

449

Two-stage hybrid microcircuit amplifier  

SciTech Connect

This report documents the design, development, and fabrication of a two-stage amplifier operating at 400 to 600 MHz. Included are characterization data, predictions generated during design, and measured performance.

Pyo, M.L.

1987-04-01

450

Real Time Calibration Method for Signal Conditioning Amplifiers  

NASA Technical Reports Server (NTRS)

A signal conditioning amplifier receives an input signal from an input such as a transducer. The signal is amplified and processed through an analog to digital converter and sent to a processor. The processor estimates the input signal provided by the transducer to the amplifier via a multiplexer. The estimated input signal is provided as a calibration voltage to the amplifier immediately following the receipt of the amplified input signal. The calibration voltage is amplified by the amplifier and provided to the processor as an amplified calibration voltage. The amplified calibration voltage is compared to the amplified input signal, and if a significant error exists, the gain and/or offset of the amplifier may be adjusted as necessary.

Medelius, Pedro J. (Inventor); Mata, Carlos T. (Inventor); Eckhoff, Anthony (Inventor); Perotti, Jose (Inventor); Lucena, Angel (Inventor)

2004-01-01

451

MMIC Amplifiers for 90 to 130 GHz  

NASA Technical Reports Server (NTRS)

This brief describes two monolithic microwave integrated-circuit (MMIC) amplifier chips optimized to function in the frequency range of 90 to 130 GHz, covering nearly all of F-band (90 - 140 GHz). These amplifiers were designed specifically for local-oscillator units in astronomical radio telescopes such as the Atacama Large Millimeter Array (ALMA). They could also be readily adapted for use in electronic test equipment, automotive radar systems, and communications systems that operate between 90 and 130 GHz.

Samoska, Lorene; Pukala, David; Peralta, Alejandro; Bryerton, Eric; Morgan, Matt; Boyd, T.; Hu, Ming; Schmitz, Adele

2007-01-01

452

Distributed fiber Raman amplifiers with localized loss  

Microsoft Academic Search

Backward pumped C- and L-band distributed fiber Raman amplifiers are described, where discrete losses from 0-8 dB were added at various positions to examine the effect of localized loss. Below 3-dB additional loss, the overall optical performance degraded similarly, regardless of loss position in a hybrid Raman and erbium-doped fiber amplifier. Above 3 dB, the performance degradation worsened as the

Seung Kwan Kim; Sun Hyok Chang; Jin Soo Han; Moo-Jung Chu; Jong Hyun Lee

2003-01-01

453

Characteristics of low noise hybrid fiber amplifier  

Microsoft Academic Search

The characteristics of hybrid fiber amplifier (HFA) are investigated. HFA is composed of three stages: short-length EDFA pre-stage, DCF Raman amplifier, and power boosting EDFA. HFA has low noise figure, high output power, and also wide input power dynamic range. Gain control method of HFA is presented experimentally, and the transient gain excursion is suppressed to less than 0.5dB at

Sun Hyok Chang; Jin Soo Han; Hee Sang Chung; Kwangjoon Kim; Je Soo Ko

2006-01-01

454

Characteristics of low noise hybrid fiber amplifier  

Microsoft Academic Search

The characteristics of hybrid fiber amplifier (HFA) are investigated. HFA is composed of three stages: short-length EDFA pre-stage, DCF Raman amplifier, and power boosting EDFA. HFA has low noise figure, high output power, and also wide input power dynamic range. Gain control method of HFA is presented experimentally, and the transient gain excursion is suppressed to less than 0.5 dB

Sun Hyok Chang; Jin Soo Han; Hee Sang Chung; Kwangjoon Kim; Je Soo Ko

2006-01-01

455

Thulium-doped tellurite fiber amplifier  

Microsoft Academic Search

Gain in the S-band is demonstrated in a thulium-doped tellurite fiber amplifier using dual pump and bidirectional pumping schemes. Two pump schemes were employed: 795\\/1064 and 1047\\/1550 nm. The gain profile is broader than achieved in a fluoride fiber and overlaps with the C-band of the erbium-doped fiber amplifier. We reach a fiber-to-fiber gain of 11 dB and an internal

E. R. M. Taylor; L. N. Ng; J. Nilsson; R. Caponi; A. Pagano; M. Potenza; B. Sordo

2004-01-01

456

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

Han, Kwang S.; Hwang, In Heon; Stock, Larry V.

1989-01-01

457

A Ku band internally matched high power GaN HEMT amplifier with over 30% of PAE  

NASA Astrophysics Data System (ADS)

We report a high power Ku band internally matched power amplifier (IMPA) with high power added efficiency (PAE) using 0.3 ?m AlGaN/GaN high electron mobility transistors (HEMTs) on 6H-SiC substrate. The internal matching circuit is designed to achieve high power output for the developed devices with a gate width of 4 mm. To improve the bandwidth of the amplifier, a T type pre-matching network is used at the input and output circuits, respectively. After optimization by a three-dimensional electromagnetic (3D-EM) simulator, the amplifier demonstrates a maximum output power of 42.5 dBm (17.8 W), PAE of 30% to 36.4% and linear gain of 7 to 9.3 dB over 13.8-14.3 GHz under a 10% duty cycle pulse condition when operated at Vds = 30 V and Vgs = -4 V. At such a power level and PAE, the amplifier exhibits a power density of 4.45 W/mm.

Qin, Ge; Xiaojuan, Chen; Weijun, Luo; Tingting, Yuan; Yan, Pu; Xinyu, Liu

2012-01-01

458

Multiple excitation regenerative amplifier inertial confinement system  

DOEpatents

The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation. 11 figs.

George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

1980-05-27

459

Multiple excitation regenerative amplifier inertial confinement system  

DOEpatents

The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation.

George, Victor E. [Livermore, CA; Haas, Roger A. [Pleasanton, CA; Krupke, William F. [Pleasanton, CA; Schlitt, Leland G. [Livermore, CA

1980-05-27

460

V-band IMPATT power amplifier  

NASA Technical Reports Server (NTRS)

This program is the result of the continuing demand and future requirement for a high data rate 60-GHz communications link. A reliable solid-state transmitter which delivers the necessary power over a wide bandwidth using the present IMPATT diode technology required the development of combining techniques. The development of a 60-GHz IMPATT power combiner amplifier is detailed. The results form a basis from which future wideband, high-power IMPATT amplifiers may be developed. As a result, several state-of-the-art advancements in millimeter-wave components technology were achieved. Specific achievements for the amplifier integration were: development of a nonresonant divider/combiner circuit; reproducible multiple junction circulator assemblies; and reliable high power 60-GHz IMPATT diodes. The various design approaches and tradeoffs which lead to the final amplifier configuration are discussed. A detailed circuit design is presented for the various amplifier components, and the conical line combiner, radial line combiner, and circulator development are discussed. The performance of the amplifier, the overall achievement of the program, the implications of the results, and an assessment of future development needs and recommendations are examined.

Schell, S. W.

1985-01-01

461

Amorphous silicon pixel radiation detectors and associated thin film transistor electronics readout  

SciTech Connect

We describe the characteristics of thin (1 {mu}m) and thick (>30 {mu}m) hydrogenated amorphous silicon p-i-n diodes which are optimized for detecting and recording the spatial distribution of charged particles, x-rays and {gamma} rays. For x-ray, {gamma} ray, and charged particle detection we can use thin p-i-n photosensitive diode arrays coupled to evaporated layers of suitable scintillators. For direct detection of charged particles with high resistance to radiation damage, we use the thick p-i-n diode arrays. Deposition techniques using helium dilution, which produce samples with low stress are described. Pixel arrays for flux exposures can be readout by transistor, single diode or two diode switches. Polysilicon charge sensitive pixel amplifiers for single event detection are described. Various applications in nuclear, particle physics, x-ray medical imaging, neutron crystallography, and radionuclide chromatography are discussed.

Perez-Mendez, V.; Drewery, J.; Hong, W.S.; Jing, T.; Kaplan, S.N.; Lee, H.; Mireshghi, A.

1994-10-01

462

Multi-pass light amplifier  

NASA Technical Reports Server (NTRS)

A multiple-pass laser amplifier that uses optical focusing between subsequent passes through a single gain medium so that a reproducibly stable beam size is achieved within the gain region. A resonator or a White Cell cavity is provided, including two or more mirrors (planar or curvilinearly shaped) facing each other along a resonator axis and an optical gain medium positioned on a resonator axis between the mirrors or adjacent to one of the mirrors. In a first embodiment, two curvilinear mirrors, which may include adjacent lenses, are configured so that a light beam passing through the gain medium and incident on the first mirror is reflected by that mirror toward the second mirror in a direction approximately parallel to the resonator axis. A light beam translator, such as an optical flat of transparent material, is positioned to translate this light beam by a controllable amount toward or away from the resonator axis for each pass of the light beam through the translator. A second embodiment uses two curvilinear mirrors and one planar mirror, with a gain medium positioned in the optical path between each curvilinear mirror and the planar mirror. A third embodiment uses two curvilinear mirrors and two planar mirrors, with a gain medium positioned adjacent to a planar mirror. A fourth embodiment uses a curvilinear mirror and three planar mirrors, with a gain medium positioned adjacent to a planar mirror. A fourth embodiment uses four planar mirrors and a focusing lens system, with a gain medium positioned between the four mirrors. A fifth embodiment uses first and second planar mirrors, a focusing lens system and a third mirror that may be planar or curvilinear, with a gain medium positioned adjacent to the third mirror. A sixth embodiment uses two planar mirrors and a curvilinear mirror and a fourth mirror that may be planar or curvilinear, with a gain medium positioned adjacent to the fourth mirror. In a seventh embodiment, first and second mirrors face a third mirror, all curvilinear, in a White Cell configuration, and a gain medium is positioned adjacent to one of the mirrors.

Plaessmann, Henry (Inventor); Grossman, William M. (Inventor); Olson, Todd E. (Inventor)

1996-01-01

463

An ion-gated bipolar amplifier for ion sensing with enhanced signal and improved noise performance  

NASA Astrophysics Data System (ADS)

This work presents a proof-of-concept ion-sensitive device operating in electrolytes. The device, i.e., an ion-gated bipolar amplifier (IGBA), consists of a modified ion-sensitive field-effect transistor (ISFET) intimately integrated with a vertical bipolar junction transistor for immediate current amplification without introducing additional noise. With the current non-optimized design, the IGBA is already characterized by a 70-fold internal amplification of the ISFET output signal. This signal amplification is retained when the IGBA is used for monitoring pH variations. The tight integration significantly suppresses the interference of the IGBA signal by external noise, which leads to an improvement in signal-to-noise performance compared to its ISFET reference. The IGBA concept is especially suitable for biochips with millions of electric sensors that are connected to peripheral readout circuitry via extensive metallization which may in turn invite external interferences leading to contamination of the signal before it reaches the first external amplification stage.

Zhang, Da; Gao, Xindong; Chen, Si; Norström, Hans; Smith, Ulf; Solomon, Paul; Zhang, Shi-Li; Zhang, Zhen

2014-08-01

464

Ion-selective electrolyte-gated field-effect transistors: prerequisites for proper functioning  

NASA Astrophysics Data System (ADS)

Electrolyte-gated organic field-effect transistors (EGOFETs) used as transducers and amplifiers in potentiometric sensors have recently attracted a significant amount of scientific interest. For that reason, the fundamental prerequisites to achieve a proper potentiometric signal amplification and transduction are examined. First, polarizable as well as non-polarizable semiconductor- and gate-electrolyte- interface combinations are investigated by normal pulse voltammetry. The results of these measurements are correlated with the corresponding transistor characteristics, clarifying the functional principle of EGOFETs and the requirements for high signal amplification. In addition to a good electrical performance, the EGOFET-transducers should also be compatible with the targeted sensing application. Accordingly, the influence of different gate materials and electrolytes on the sensing abilities, are discussed. Even though all physical requirements are met, EGOFETs typically exhibit irreversible degradation, if the gate potential exceeds a certain level. For that reason, EGOFETs have to be operated using a constant source-drain operation mode which is presented by means of an H+ (pH) sensitive ion-sensor.

Kofler, Johannes; Schmoltner, Kerstin; List-Kratochvil, Emil J. W.

2014-10-01

465

Toward 300 mm wafer-scalable high-performance polycrystalline chemical vapor deposited graphene transistors.  

PubMed

The largest applications of high-performance graphene will likely be realized when combined with ubiquitous Si very large scale integrated (VLSI) technology, affording a new portfolio of "back end of the line" devices including graphene radio frequency transistors, heat and transparent conductors, interconnects, mechanical actuators, sensors, and optical devices. To this end, we investigate the scalable growth of polycrystalline graphene through chemical vapor deposition (CVD) and its integration with Si VLSI technology. The large-area Raman mapping on CVD polycrystalline graphene on 150 and 300 mm wafers reveals >95% monolayer uniformity with negligible defects. About 26,000 graphene field-effect transistors were realized, and statistical evaluation indicates a device yield of ? 74% is achieved, 20% higher than previous reports. About 18% of devices show mobility of >3000 cm(2)/(V s), more than 3 times higher than prior results obtained over the same range from CVD polycrystalline graphene. The peak mobility observed here is ? 40% higher than the peak mobility values reported for single-crystalline graphene, a major advancement for polycrystalline graphene that can be readily manufactured. Intrinsic graphene features such as soft current saturation and three-region output characteristics at high field have also been observed on wafer-scale CVD graphene on which frequency doubler and amplifiers are demonstrated as well. Our growth and transport results on scalable CVD graphene have enabled 300 mm synthesis instrumentation that is now commercially available. PMID:25198884

Rahimi, Somayyeh; Tao, Li; Chowdhury, Sk Fahad; Park, Saungeun; Jouvray, Alex; Buttress, Simon; Rupesinghe, Nalin; Teo, Ken; Akinwande, Deji

2014-10-28

466

Flexible polymer transistors with high pressure sensitivity for application in electronic skin and health monitoring  

NASA Astrophysics Data System (ADS)

Flexible pressure sensors are essential parts of an electronic skin to allow future biomedical prostheses and robots to naturally interact with humans and the environment. Mobile biomonitoring in long-term medical diagnostics is another attractive application for these sensors. Here we report the fabrication of flexible pressure-sensitive organic thin film transistors with a maximum sensitivity of 8.4?kPa-1, a fast response time of <10?ms, high stability over >15,000 cycles and a low power consumption of <1?mW. The combination of a microstructured polydimethylsiloxane dielectric and the high-mobility semiconducting polyisoindigobithiophene-siloxane in a monolithic transistor design enabled us to operate the devices in the subthreshold regime, where the capacitance change upon compression of the dielectric is strongly amplified. We demonstrate that our sensors can be used for non-invasive, high fidelity, continuous radial artery pulse wave monitoring, which may lead to the use of flexible pressure sensors in mobile health monitoring and remote diagnostics in cardiovascular medicine.

Schwartz, Gregor; Tee, Benjamin C.-K.; Mei, Jianguo; Appleton, Anthony L.; Kim, Do Hwan; Wang, Huiliang; Bao, Zhenan

2013-05-01

467

Method to amplify variable sequences without imposing primer sequences  

DOEpatents

The present invention provides methods of amplifying target sequences without including regions flanking the target sequence in the amplified product or imposing amplification primer sequences on the amplified product. Also provided are methods of preparing a library from such amplified target sequences.

Bradbury, Andrew M.; Zeytun, Ahmet

2006-11-14

468

Efficiency of low power audio amplifiers and loudspeakers  

Microsoft Academic Search

We look at the load presented to audio amplifiers by real transducers. We consider the power losses in class-AB and class-D amplifier topologies, and determine that in order to predict efficiency it is necessary to consider the amplifier\\/transducer combination. The ability of the class-D amplifier to recycle quadrature load current offers new ways to improve efficiency

S. Burrow; D. Grant

2001-01-01

469

NEW CONCEPT OF A HYBRID AMPLIFIER FOR DRIVING PIEZOELECTRIC ACTUATORS  

Microsoft Academic Search

This paper describes a new concept of an amplifier for piezoelectric actuators, which combines the high efficiency of a switching amplifier with the output signal accuracy of an analogue amplifier. This so-called hybrid amplifier includes a bidirectional switching voltage source and an analogue final stage. The description of the control unit for the switching power supply with its unconventional structure

Christoph Stiebel; Hartmut Janocha

470

Gain analysis of Erbium and Ytterbium Doped Optical Fiber Amplifiers  

Microsoft Academic Search

In this study, importance of optical amplifiers which are used in optical communication systems is explained and gains of EDFA, Erbium Doped Fiber Amplifier, and YDFA, Ytterbium Doped Fiber Amplifier, which are among the most commonly used optical amplifiers today, are analysed based on their performance parameters. The effects of the power of input signal, the power of pump laser,

Tolga Kucukarslan; N. Ozlem Unverdi

2012-01-01

471

Improved Grid-Array Millimeter-Wave Amplifier  

NASA Technical Reports Server (NTRS)

Improved grid-array amplifiers operating at millimeter and submillimeter wavelengths developed for use in communications and radar. Feedback suppressed by making input polarizations orthogonal to output polarizations. Amplifier made to oscillate by introducing some feedback. Several grid-array amplifiers concatenated to form high-gain beam-amplifying unit.

Rosenberg, James J.; Rutledge, David B.; Smith, R. Peter; Weikle, Robert

1993-01-01

472

Recent progress in photoactive organic field-effect transistors  

NASA Astrophysics Data System (ADS)

Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

2014-04-01

473

Tunable dye laser amplifier chain for laser isotope separation  

SciTech Connect

A tunable dye laser amplifier chain developed for experiments on atomic vapour laser isotope separation (AVLIS) is described. The system, pumped by copper vapour lasers, consists of a master oscillator and an amplifier stage including a preamplifier and three main amplifiers working in the saturation mode. The master oscillator of the stage is a dye laser with a grazing incidence diffraction grating. Longitudinal pumping of the amplifiers is used. The efficiency of the main amplifiers is 50 % - 55 %. The average power of laser radiation at the output of the last amplifier is 100 W. (lasers. amplifiers)

Grigoriev, Igor' S; D'yachkov, Aleksei B; Labozin, Valerii P; Mironov, Sergei M; Nikulin, Sergei A; Firsov, Valerii A [Russian Research Centre 'Kurchatov Institute', Moscow (Russian Federation)

2004-05-31

474

Uniformity of fully gravure printed organic field-effect transistors  

Microsoft Academic Search

Fully mass-printed organic field-effect transistors were made completely by means of gravure printing. Therefore a special printing layout was developed in order to avoid register problems in print direction. Upon using this layout, contact pads for source–drain electrodes of the transistors are printed together with the gate electrodes in one and the same printing run. More than 50,000 transistors have

M. Hambsch; K. Reuter; M. Stanel; G. Schmidt; H. Kempa; U. Fügmann; U. Hahn; A. C. Hübler

2010-01-01

475

A PWM transistor inverter for an ac electric vehicle drive  

Microsoft Academic Search

A prototype system consisting of closely integrated motor, inverter, and transaxle has been built in order to demonstrate the feasibility of a three-phase ac transistorized inverter for electric vehicle applications. The microprocessor-controlled inverter employs monolithic power transistors to drive an oil-cooled, three-phase induction traction motor at a peak output power of 30 kW from a 144 V battery pack. Transistor

J. M. Slicker

1981-01-01

476

100GHz Transistors from Wafer-Scale Epitaxial Graphene  

Microsoft Academic Search

The high carrier mobility of graphene has been exploited in field-effect transistors that operate at high frequencies. Transistors were fabricated on epitaxial graphene synthesized on the silicon face of a silicon carbide wafer, achieving a cutoff frequency of 100 gigahertz for a gate length of 240 nanometers. The high-frequency performance of these epitaxial graphene transistors exceeds that of state-of-the-art silicon

Y.-M. Lin; C. Dimitrakopoulos; K. A. Jenkins; D. B. Farmer; H.-Y. Chiu; A. Grill; Ph. Avouris

2010-01-01

477

Organic Inverter Using Monolithically Stacked Static Induction Transistors  

Microsoft Academic Search

We fabricated monolithic organic inverters using a stacked structure of two organic static induction transistors (SITs). The operating characteristics of a p-channel transistor load and p-channel transistor drive-type inverter in which pentacene films are employed as an organic semiconductor material are described. The gain transfer characteristics of a pentacene SIT inverter based on an enhancement-load\\/enhancement-drive layout showed a threshold voltage

Hiroyuki Iechi; Yasuyuki Watanabe; Hiroshi Yamauchi; Kazuhiro Kudo

2010-01-01

478

Transistorized PWM Inverter-Induction Motor Drive System  

Microsoft Academic Search

The development of a transistorized pulsewidth modulated (PWM) inverter-induction motor traction drive system is described. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and

Steven C. Peak; Allan B. Plunkett

1983-01-01

479

BJT AC Analysis 1 of 38 The re Transistor model  

E-print Network

BJT AC Analysis 1 of 38 The re Transistor model Remind Q-poiint re = 26mv/IE #12;BJT AC Analysis 2;BJT AC Analysis 3 of 38 Process Replace transistor with small-signal model. Replace capacitors 5.0ms I(C1) -400nA 0A 400nA (4.2708m,-222.757n) (4.2195m,217.707n) Using these values the transistor

Allen, Gale

480

Correlating the radiation response of MOS capacitors and transistors  

Microsoft Academic Search

A new technique is presented for separating the threshold-voltage shift of an MOS transistor into shifts due to interface states and trapped-oxide charge. Using this technique, the radiation responses of MOS capacitors and transistors fabricated on the same wafer are compared. A good correlation is observed between p-substrate capacitors and n-channel transistors irradiated at 10 V, as well as between

P. S. Winokur; P. V. Dressendorfer; P. J. McWhorter; J. R. Schwank; D. C. Turpin

1984-01-01

481

A computational study of ballistic silicon nanowire transistors  

Microsoft Academic Search

Using a rigorous 3D quantum simulator, we report a computational study of ballistic silicon nanowire transistors with arbitrary cross sections (i.e., triangular, rectangular or cylindrical). In comparison with the planar double-gate MOSFET, the silicon nanowire transistor shows promise (e.g., better electrostatic scaling for a given Si body thickness) and may provide a manufacturable opportunity to scale silicon transistors down below

J. Wang; E. Polizzi; M. Lundstrom

2003-01-01

482

GaS and GaSe ultrathin layer transistors.  

PubMed

Room-temperature, bottom-gate, field-effect transistor characteristics of 2D ultrathin layer GaS and GaSe prepared from the bulk crystals using a micromechanical cleavage technique are reported. The transistors based on active GaS and GaSe ultrathin layers demonstrate typical n-and p-type conductance transistor operation along with a good ON/OFF ratio and electron differential mobility. PMID:22678832

Late, Dattatray J; Liu, Bin; Luo, Jiajun; Yan, Aiming; Matte, H S S Ramakrishna; Grayson, Matthew; Rao, C N R; Dravid, Vinayak P

2012-07-10

483

Electrodeposited p-type magnetic metal-base transistor  

Microsoft Academic Search

In this work the development of a magnetic metal-base transistor that operates by hole transport is reported. The transistor is constructed using p-type silicon as the collector, Co as the base, and Cu2O as the emitter. Both base and emitter are deposited using electrochemical procedures. The transistor shows a magnetic-field-dependent current gain and a magnetocurrent of ~40% observed for a

Rafael Gallina Delatorre; Maximiliano Luis Munford; Vagner Stenger; André Avelino Pasa; Walther Schwarzacher; Michelle S. Meruvia; Ivo A. Hümmelgen

2006-01-01

484

Electrodeposited p-type magnetic metal-base transistor  

NASA Astrophysics Data System (ADS)

In this work the development of a magnetic metal-base transistor that operates by hole transport is reported. The transistor is constructed using p-type silicon as the collector, Co as the base, and Cu2O as the emitter. Both base and emitter are deposited using electrochemical procedures. The transistor shows a magnetic-field-dependent current gain and a magnetocurrent of ~40% observed for a low emitter current value of 2 mA.

Delatorre, Rafael Gallina; Munford, Maximiliano Luis; Stenger, Vagner; Pasa, André Avelino; Schwarzacher, Walther; Meruvia, Michelle S.; Hümmelgen, Ivo A.

2006-04-01

485

Black phosphorus field-effect transistors.  

PubMed

Two-dimensional crystals have emerged as a class of materials that may impact future electronic technologies. Experimentally identifying and characterizing new functional two-dimensional materials is challenging, but also potentially rewarding. Here, we fabricate field-effect transistors based on few-layer black phosphorus crystals with thickness down to a few nanometres. Reliable transistor performance is achieved at room temperature in samples thinner than 7.5 nm, with drain current modulation on the order of 10(5) and well-developed current saturation in the I-V characteristics. The charge-carrier mobility is found to be thickness-dependent, with the highest values up to ? 1,000 cm(2) V(-1) s(-1) obtained for a thickness of ? 10 nm. Our results demonstrate the potential of black phosphorus thin crystals as a new two-dimensional material for applications in nanoelectronic devices. PMID:24584274

Li, Likai; Yu, Yijun; Ye, Guo Jun; Ge, Qingqin; Ou, Xuedong; Wu, Hua; Feng, Donglai; Chen, Xian Hui; Zhang, Yuanbo

2014-05-01

486

A silicon nanocrystal tunnel field effect transistor  

SciTech Connect

In this work, we demonstrate a silicon nanocrystal Field Effect Transistor (ncFET). Its operation is similar to that of a Tunnelling Field Effect Transistor (TFET) with two barriers in series. The tunnelling barriers are fabricated in very thin silicon dioxide and the channel in intrinsic polycrystalline silicon. The absence of doping eliminates the problem of achieving sharp doping profiles at the junctions, which has proven a challenge for large-scale integration and, in principle, allows scaling down the atomic level. The demonstrated ncFET features a 10{sup 4} on/off current ratio at room temperature, a low 30?pA/?m leakage current at a 0.5?V bias, an on-state current on a par with typical all-Si TFETs and bipolar operation with high symmetry. Quantum dot transport spectroscopy is used to assess the band structure and energy levels of the silicon island.

Harvey-Collard, Patrick, E-mail: P.Collard@USherbrooke.ca [Département de Physique, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec J1K 2R1 (Canada); Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Laboratoire Nanotechnologies Nanosystèmes (LN2)–CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Drouin, Dominique [Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Laboratoire Nanotechnologies Nanosystèmes (LN2)–CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Pioro-Ladrière, Michel [Département de Physique, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec J1K 2R1 (Canada); CIFAR Program in Quantum Information Science, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1Z8 (Canada)

2014-05-12

487

Radiation effects on power transistor performance  

NASA Technical Reports Server (NTRS)

The D60T, D62T, and D75T transistors in the nuclear reactor were irradiated with bias voltage and high current I sub c vs. V sub ec curves were obtained to evaluate gain degradation at high power levels. Pre- and post-irradiation high current switching tests were performed to evaluate the response. The gamma ray damage work done at Sandia was correlated with the neutron work done at the O.S.U. reactor with the above specified transistors. Theoretical analyses of damage and electrical performance were conducted in terms of semiconductor physics. The experimental high current pulser was improved in order to measure switching time changes which are less than one microsecond at currents of 100 to 200 amperes for in-situ testing.

Frasca, Albert J.

1987-01-01

488

High power, high beam quality regenerative amplifier  

DOEpatents

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

Hackel, L.A.; Dane, C.B.

1993-08-24

489

High power, high beam quality regenerative amplifier  

DOEpatents

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

1993-01-01

490

Pulsed ti: sapphire laser power amplifier  

SciTech Connect

We have demonstrated an all solid state Ti:Sapphire laser system consisting of a power oscillator and single pass amplifier. The electrical-to-optical efficiency far exceeds that of the current CW systems. The pump lasers have lower capital and operating costs than the Argon-ion laser. In the future, we plan to scale the output power to higher levels by adding a fourth pump laser and improving the output power of the current pump lasers. Modeling results suggest that a large increase in efficiency can be realized by improving the beam quality of the pump lasers, even at the cost of reduced output power. We will explore this option by adding apertures to the cavity and/or reducing the rod diameter along with optimizing the resonator design. Other improvements in efficiency which will be investigated include double passing the amplifier for better extraction. To complete this work, the laser system will be converted into a two-stage amplifier. A narrow band, lower power oscillator currently under development will be injected in to the amplifier to study the extraction and efficiency characteristics of the amplifier throughout the tuning range of Ti:Sapphire. Detailed beam quality measurements will also be made. Other work will include doubling the narrow band output for materials processing applications.

Crozier, D W; Ault, Ault, E R; Erbert, G; Pierce, E L; Sleaford, B W

1999-02-23

491

Silicon nanowire transistors for electron biosensors  

Microsoft Academic Search

A method of nanostructuring of silicon-on-insulator (SOI) layers on the basis of gas etching in XeF2 or SF6:CFCl3 is developed for the purpose of obtaining SOI nanowire structures. SOI nanowire transistors (SOI NWTs) with free channels,\\u000a used as sensors in electron detectors, are fabricated and tested. The results of experiments show that the method used to\\u000a fabricate nanowires requires no

O. V. Naumova; B. I. Fomin; L. N. Safronov; D. A. Nasimov; M. A. Ilnitskii; N. V. Dudchenko; S. F. Devyatova; E. D. Zhanaev; V. P. Popov; A. V. Latyshev; A. L. Aseev

2009-01-01

492

High performance microwave static induction transistors  

Microsoft Academic Search

This paper describes recent developments in silicon high-voltage, high-power microwave static induction transistor (SIT) technology. We have developed SITs which are capable of cw output power levels greater than 100W in the 200 MHz to 400 MHz frequency band and 25W in the 900 MHz to 1200 MHz frequency band at 120V dc operating voltage. These SITs demonstrate the highest

A. Cogan; R. Regan; I. Bencuya; S. Butler; F. Rock

1983-01-01

493

Organic static induction transistor for display devices  

Microsoft Academic Search

Organic static induction transistors (SITs) for display devices are proposed and the basic electrical characteristics of the SITs are investigated. The organic SITs, using a copper phthalocyanine (CuPc) evaporated film as an active layer, have a layered structure of Au (drain)\\/CuPc\\/Al (gate)\\/CuPc\\/Au (source)\\/glass. The electrical characteristics show that the current flow from the source to drain electrodes is controlled by

K Kudo; D. X Wang; M Iizuka; S Kuniyoshi; K Tanaka

2000-01-01

494

Modelling DC characteristics of static induction transistors  

Microsoft Academic Search

To analyse and design non-linear circuits using static induction transistors (SITs), a new empirical equation is presented to relate drain current to drain-source and gate-source voltages. The parameters of this equation can easily be obtained from the drain characteristics of the SIT. Using this equation, a closed-form expression can be obtained for the amplification factor of the SIT. Good agreement

Muhammad Taher Abuelma'Atti

1985-01-01

495

Static induction transistors - HF to X band  

Microsoft Academic Search

The operation principles and the advantages of static induction transistors (SITs) are discussed with special attention given to silicon SITs. Some of the performance characteristics (such as voltage gain, transconductance, and capacitance) of recently fabricated silicon surface-gate SITs (SGSITs) and of a computer-simulated GaAs SIT are presented. It is shown that, while the SGSITSs exhibit excellent output power and efficiency

Robert J. Regan; Scott J. Butler; Craig A. Armiento; Frederick C. Rock

1987-01-01

496

Interfacial electronic traps in surface controlled transistors  

Microsoft Academic Search

Carrier recombination at interfacial electronic traps under a surface controlling gate electrode is analyzed using the Shockley-Reed-Hall steady-state recombination kinetics to provide a theoretical basis for quantifying the direct-current current-voltage (DCIV) method for monitoring and diagnosis of MOS transistor reliability, design, and manufacturing processes. Analytical expressions for DCIV lineshape, linewidth, peak gate-voltage and peak amplitude are derived for the determination

Jin Cai; Chih-Tang Sah

2000-01-01

497

p-type metal-base transistor  

Microsoft Academic Search

In this work we present data from a novel p-type metal-base transistor with common-base gain alpha~1, fabricated at ambient temperature and pressure by electrodepositing sequentially on a p-type Si collector, a Co base and a Cu2O emitter. The high gain and the dependence of potential between emitter and base (VEB) on the potential between collector and base (VCB) when the

R. G. Delatorre; M. L. Munford; R. Zandonay; V. C. Zoldan; A. A. Pasa; W. Schwarzacher; M. S. Meruvia; I. A. Hümmelgen

2006-01-01

498

Polymer space-charge-limited transistor  

Microsoft Academic Search

A metal grid is sandwiched between poly(3-hexylthiophene) to form a solid-state version of vacuum tube triode, where the vertical space-charge-limited current is modulated by the grid potential. The Al grid contains random submicron openings formed by a nonlithographic method. The multilayer polymer structure is made by spin coating. The operating voltage of the polymer space-charge-limited transistor is 3 V, and

Yu-Chiang Chao; Hsin-Fei Meng; Sheng-Fu Horng

2006-01-01

499

Avalanche injection and second breakdown in transistors  

Microsoft Academic Search

A rapid type of second breakdown observed in silicon n+-p-n-n+transistors is shown to be due to avalanche injection at the collector n-n+junction. Localized thermal effects, which are usually associated With second breakdown, are shown to play a minor role in the initiation of the transition to the low voltage state. A useful tool in the analysis of avalanche injection is

P. L. Hower; V. G. Krishna Reddi

1970-01-01

500

Electroluminescence from a Single-Nanocrystal Transistor  

Microsoft Academic Search

We report the fabrication and characterization of light-emitting transistors incorporating individual cadmium selenide (CdSe) nanocrystals. Electrical measurements conducted at low bias voltage and low temperature show clear evidence of Coulomb blockade behavior, indicating that electrons pass through the nanocrystal by single-electron tunneling. Once the bias voltage exceeds the band gap of CdSe, devices with asymmetric tunnel barriers emit linearly polarized

Mark S. Gudiksen; Kristin N. Maher; Lian Ouyang; Hongkun Park

2005-01-01