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1

Distributed amplifier using Josephson vortex flow transistors  

SciTech Connect

A wide-band traveling wave amplifier using vortex flow transistors is proposed. A vortex flow transistor is a long Josephson junction used as a current controlled voltage source. The dual nature of this device to the field effect transistor is exploited. A circuit model of this device is proposed and a distributed amplifier utilizing 50 vortex flow transistors is predicted to have useful gain to 100 GHz.

McGinnis, D.P.; Beyer, J.B.; Nordman, J.E.

1986-06-01

2

Intermodulation distortion behavior in LDMOS transistor amplifiers  

Microsoft Academic Search

An analysis of the intermodulation distortion (IMD) behavior of LDMOS transistor amplifiers is presented. It is shown that the turn-on region abruptness compared to most other devices is important for explaining the measured IMD behavior such as sweet-spots. The analysis is validated using two-tone measurements at low frequency for different classes of operation. A 1.9 GHz LDMOS power amplifier is

C. Fager; N. B. de Carvalho; Jost Carlos Pedro; H. Zirath

2002-01-01

3

Field-Effect Transistor RF Power Amplifiers.  

National Technical Information Service (NTIS)

The report documents the results of a series of tests devised to evaluate state-of-the-art field-effect transistors (FETs) as RF power amplifiers. Power output, gain and efficiency are studied; special attention is given to reliability and intermodulation...

M. Ringel

1971-01-01

4

Fully differential cryogenic transistor amplifier  

NASA Astrophysics Data System (ADS)

We have constructed a dc-coupled differential amplifier capable of operating in the 4.2 K-300 K temperature range. The amplifier can be operated at high-bias setting, where it dissipates 5 mW, has noise temperature TN ? 0.7 K at RS ? 5 k? and >40 MHz bandwidth at 4.2 K bath temperature. The bias setting can be adjusted: at our lowest tested setting the amplifier dissipates <100 ?W, has noise temperature TN ? 2 K at RS ? 25 k? and >2 MHz bandwidth. The 1/f noise corner frequency is a few times 10 kHz. We foresee the amplifier to have an application in the readout of Superconducting Quantum Interference Devices (SQUIDs), Superconducting Tunnel Junction Detectors (STJs) and Transition Edge Sensors (TESes). We have verified the practical use of the amplifier by reading out a 4.2 K 480-SQUID array with 40 MHz bandwidth and <8 × 10-8 ?0/Hz1/2 flux noise.

Beev, Nikolai; Kiviranta, Mikko

2013-10-01

5

Experimental results of a vortex flow transistor amplifier  

SciTech Connect

A Niobium based superconducting amplifier consisting of a series array of 60 vortex flow transistors (VFT) was fabricated and tested. Each VFT consisted of a long Josephson junction biased in the flux flow state, magnetically coupled to a current carrying control line. The topology of the circuit is based on a distributed amplifier configuration. The transresistance of the amplifier in a 50 Ohm environment for frequencies up to 1 MHz was measured.

McGinnis, D.P.; Hohenwarter, G.K.G.; Ketkar, M.; Beyer, J.B.; Nordman, J.E.

1989-03-01

6

Cryogenic ultra-low-noise SiGe transistor amplifier.  

PubMed

An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz-100 MHz. A noise temperature T(N) ? 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ~50 ?. The voltage gain of the amplifier was 25 dB at a power consumption of 720 ?W. The input voltage noise spectral density of the amplifier is about 35 pV/?Hz. The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers. PMID:22047315

Ivanov, B I; Trgala, M; Grajcar, M; Il'ichev, E; Meyer, H-G

2011-10-01

7

Triple-Mode Single-Transistor Graphene Amplifier and Its Applications  

Microsoft Academic Search

In this article, we propose and experimentally demonstrate a triple-mode single-transistor graphene amplifier utilizing a three-terminal back-gated single-layer graphene transistor. The ambipolar nature of electronic transport in graphene transistors leads to increased amplifier functionality as compared to amplifiers built with unipolar semiconductor devices. The ambipolar graphene transistors can be configured as n-type, p-type, or hybrid-type by changing the gate bias.

Xuebei Yang; Guanxiong Liu; Alexander A Balandin; Kartik Mohanram

2010-01-01

8

Cryogenic, Low-Noise High Electron Mobility Transistor Amplifiers for the Deep Space Network.  

National Technical Information Service (NTIS)

The rapid advances recently achieved by cryogenically cooled high electron mobility transistor (HEMT) low-noise amplifiers (LNA's) in the 1- to 10-GHz range are making them extremely competitive with maser amplifiers. In order to address future spacecraft...

J. J. Bautista

1993-01-01

9

Microwave YIG-tuned transistor oscillator amplifier design: application to C band  

Microsoft Academic Search

An approach to the design of a microwave YIG-tuned transistor oscillator amplifier is discussed in this paper. A classic lumped-element model of the transistor is used to show that a simple but still accurate equivalent circuit can be useful in predicting the effect of transistor parameters on the tuning range of a microwave oscillator. On the other hand, this paper

P. M. Ollivier

1972-01-01

10

Origin of 1\\/f PM and AM noise in bipolar junction transistor amplifiers  

Microsoft Academic Search

In this paper we report the results of extensive research on phase modulation (PM) and amplitude modulation (AM) noise in linear bipolar junction transistor (BJT) amplifiers. BJT amplifiers exhibit 1\\/f PM and AM noise about a carrier signal that is much larger than the amplifiers thermal noise at those frequencies in the absence of the carrier signal. Our work shows

F. L. Walls; E. S. Ferre-Pikal; S. R. Jefferts

1997-01-01

11

Improvement of a Class-C Transistor Power Amplifier by Second-Harmonic Tuning  

Microsoft Academic Search

Considerations for the effects of second-harmonic reactive terminations on the performances of a UHF class-C transistor power amplifier are presented. An experimental amplifier circuit design using coupled-TEM-bar transmission lines is described. This circuit can vary the fundamental and the second-harmonic impedance terminations of the amplifier independently. With this amplifier circuit, significant improvement in the performance characteristics of a class-C power

SHAMSUR R. MAZUMDER; ATAOLLAH AZIZI; FRED E. GARDIOL

1979-01-01

12

VDMOS transistors for power amplifier in UHF band  

NASA Astrophysics Data System (ADS)

Modeling of power VDMOSFET transistors working in the UHF band is considered. VDMOSFET power structures suited to mobile radiotelephony power amplification are described. A nonlinear physical model suitable for all working regimes is developed. The elements of this model only depend on physical and technological data and bias voltages of the device. A reduced model compatible with SPICE (Simulation Program with Integrated Circuit Emphasis) is presented. A first comparison between measured and computed characteristics is presented under DC switching and small signal conditions. A methodology for the study and design of radio frequency power amplifiers in a nonlinear regime is described. The performance of these devices in terms of power gain, output power, efficiency, linearity and the drain bias influence as well as third order Intermodulation Distortion (IMD3) are considered. It is shown that IMD and power gain performances are controlled by DC output characteristics in the ohmic zone. Practical conclusions with respect to the intrinsic qualities and drawbacks of these products for UHF power amplification are drawn.

Kassmi, Kamal

13

2.3-Ghz Cryogenically Cooled HEMT (High Electron Mobility Transistor) Amplifier for DSS 13.  

National Technical Information Service (NTIS)

A prototype 2.3 GHz (S band) high electron mobility transistor (HEMT) amplifier/closed cycle refrigerator (CCR) system was installed in the DDS-13 feedcone, replacing the 2.3 GHz maser. The amplifier is cryogenically cooled to a physical temperature of 12...

L. Tanida

1987-01-01

14

Cryogenic, low-noise high electron mobility transistor amplifiers for the Deep Space Network  

Microsoft Academic Search

The rapid advances recently achieved by cryogenically cooled high electron mobility transistor (HEMT) low-noise amplifiers (LNA's) in the 1- to 10-GHz range are making them extremely competitive with maser amplifiers. In order to address future spacecraft navigation, telemetry, radar, and radio science needs, the Deep Space Network is investing both maser and HEMT amplifiers for its Ka-band (32-GHz) downlink capability.

J. J. Bautista

1993-01-01

15

Comparison of input offset voltage of differential amplifiers using bipolar transistors and field-effect transistors  

Microsoft Academic Search

A field-effect transistor (whether junction type or MOS type) has very high input impedance. For those who desire to achieve a higher input impedance, it is often asked `Why aren't FET pairs used as input stages and bipolar transistors used as output stages, since compatible FET and bipolar transistor monolithic structures have been developed?' This correspondence is a study of

H. C. Lin

1970-01-01

16

A novel amplifier linearization technique using an anti-parallel reconfigurable transistor (ART) pair  

Microsoft Academic Search

A new amplifier linearization methodology using an anti-parallel reconfigurable transistor (ART) pair is proposed. Unlike conventional linearization methods in which only one technique is employed, our ART method utilizes all terminals of an additional transistor and provides a unified pre-, post- and cubic-polynomial distortion technique for performance enhancement. Experimental results reveal a 42 dB reduction for the third-order intermodulation distortion

Tsz Yin Yum; Quan Xue; Chi Hou Chan

2004-01-01

17

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

18

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

19

Cryogenic, low-noise high electron mobility transistor amplifiers for the Deep Space Network  

NASA Technical Reports Server (NTRS)

The rapid advances recently achieved by cryogenically cooled high electron mobility transistor (HEMT) low-noise amplifiers (LNA's) in the 1- to 10-GHz range are making them extremely competitive with maser amplifiers. In order to address future spacecraft navigation, telemetry, radar, and radio science needs, the Deep Space Network is investing both maser and HEMT amplifiers for its Ka-band (32-GHz) downlink capability. This article describes the current state cryogenic HEMT LNA development at Ka-band for the DSN. Noise performance results at S-band (2.3 GHz) and X-band (8.5 GHz) for HEMT's and masers are included for completeness.

Bautista, J. J.

1993-01-01

20

Cryogenic, low-noise high electron mobility transistor amplifiers for the Deep Space Network  

NASA Astrophysics Data System (ADS)

The rapid advances recently achieved by cryogenically cooled high electron mobility transistor (HEMT) low-noise amplifiers (LNA's) in the 1- to 10-GHz range are making them extremely competitive with maser amplifiers. In order to address future spacecraft navigation, telemetry, radar, and radio science needs, the Deep Space Network is investing both maser and HEMT amplifiers for its Ka-band (32-GHz) downlink capability. This article describes the current state cryogenic HEMT LNA development at Ka-band for the DSN. Noise performance results at S-band (2.3 GHz) and X-band (8.5 GHz) for HEMT's and masers are included for completeness.

Bautista, J. J.

1993-11-01

21

Low-level MOS transistor amplifier using storage techniques  

Microsoft Academic Search

A fully integrated analog amplifier which can be used in a variety of applications either as a single element or as a cell in a LSI circuit has been developed for such applications as temperature measurements associated with thermocouples, biomedicine, low-level measurements and A\\/D converters.

R. Poujois; B. Baylac; D. Barbier; J. Ittel

1973-01-01

22

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

23

Design of a class E power amplifier with non-linear transistor output capacitance and finite DC-feed inductance  

Microsoft Academic Search

A numerical method for designing a class E power amplifier with a non-linear transistor output capacitance is presented. By matching the fundamental and second harmonic impedances of the output network, the method can be extended for designing a class E power amplifier with both non-linear transistor output capacitance and finite DC-feed inductance. A design example of 0.4 W 1.4 V

C. K. T. Chan; Christofer Toumazou

2001-01-01

24

CCD on-chip amplifiers: noise performance versus MOS transistor dimensions  

Microsoft Academic Search

The effect of change in the channel width, the channel length, and the bias current of detection-node MOS transistors, in charge-coupled-device (CCD) on-chip amplifiers is studied. A novel approach to noise optimization is shown, and criteria for choosing the optimum gate dimensions are established both in theory and practice. A new parameter, the noise electron density (in square electrons per

Peter Centen

1991-01-01

25

8.4-GHz Cryogenically Cooled HEMT (High Electron Mobility Transistor) Amplifier for DSS (Deep Space Station) 13.  

National Technical Information Service (NTIS)

A prototype 8.4 GHz (X-band) high electron mobility transistor (HEMT) amplifier/closed cycle refrigerator system was installed in the Deep Space Station 13 feedcone in August 1987. The amplifier is cryogenically cooled to a physical temperature of 12 K an...

L. Tanida

1988-01-01

26

Minimization of technological losses in industrial production of low noise-factor wide-banded transistor amplifiers  

Microsoft Academic Search

A statistical mathematical model for predicting the noise characteristics of low noise-factor transistor amplifiers (LTA) in conditions of industrial production is offered. It enables to minimize technological losses in serial production at the stage of designing and also to determine the percentage of output of valid devices, substantiating the input and output standards of quality control, depth and accuracy of

D. S. Vilmitsky

2001-01-01

27

Design and Performance of Microwave Amplifiers with GaAs Schottky-Gate Field-Effect Transistors  

Microsoft Academic Search

The design and performance of an X-band amplifier with GaAs Schottky-gate field-effect transistors are described. The amplifier achieves 20 ± 1.3-dB gain with a 5.5-dB typical noise figure (6.9 dB maximum) over the frequency range of 8.0-12.0 GHz. The VSWR at the input and output ports does not exceed 2.5:1. The minimum output power for 1-dB gain compression is +13

CHARLES A. LIECHTI; ROBERT L. TILLMAN

1974-01-01

28

DC-DC converter assisted two-stage amplifier in organic thin-film transistor technology on foil  

Microsoft Academic Search

In this work an organic dual DC-DC up-converter and an organic 2-stage operational amplifier are presented, both implemented in a thin-film organic electronics technology on foil. The converter has a conversion ratio of 2.5 and only consumes 1 µA from a 15 V power supply voltage. The converter is designed for biasing gates and backgates of transistors in a p-type

Hagen Marien; Michiel Steyaert; Erik van Veenendaal; Paul Heremans

2011-01-01

29

Realisation et Linearisation d'un Amplificateur de Puissance Hyperfrequence a Transistors Bipolaires Polarises en Classe C (Realization and Linearization of a Hyperfrequency Power Amplifier Implemented with Bipolar Transistors in Class C Polarization).  

National Technical Information Service (NTIS)

The design of a 10 W amplifier at 2.5 GHz and that of a power characteristic linearization device are discussed. The amplifier consists of 3 stages of transistors on a common base circuit with an MSC 3000 at the output. The linearization is obtained by an...

Y. Durand

1985-01-01

30

Analytical expressions for simplifying the design of broadband low noise microwave transistor amplifiers  

Microsoft Academic Search

An analytical expression for the minimum achievable noise figure for a specified gain at a given frequency is derived for a microwave amplifier. The minimum noise figure is given in terms of the specified gain, the amplifier noise parameters, and the S-parameters. Similarly, another expression for the maximum gain at a specified noise figure is derived in terms of the

G. N. Link; V. S. Rao Gudimetla

1995-01-01

31

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

32

Design technique for class E RF\\/MW amplifiers with linear equivalent of transistor's output capacitance  

Microsoft Academic Search

In class E amplifiers the nonlinear output capacitance of the device often reaches, or even exceeds the necessary value given by classical analysis in RF applications. The 100-percent efficiency condition imposes a constraint on the maximum susceptance value of the shunting capacitor consequently limiting the maximum frequency of the stage. In order to easily incorporate this nonlinear capacitance to the

Arturo Mediano; P. Molina-Gaudo; C. Bernal

2005-01-01

33

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

34

Analyse du bruit des transistors a effet de champ en technologie complementaire MOS et application a la realisation d'un amplificateur integre sensible au courant. (Analysis of the background noise of field effect transistors in MOS complementary technology and application in the construction of a current-sensitive integrated amplifier).  

National Technical Information Service (NTIS)

A low noise amplifier for use in high energy physics is developed. The origin and the mechanisms of the noise in MOSFET transistors is carried out with the aim of minimizing such effects in amplifiers. The research is applied in the construction of a curr...

E. Beuville

1989-01-01

35

Linearisation des Amplificateurs de Puissance a Transistors a Effet de Champ GaAs en Hyperfrequences (Linearization of GaAs Field Effect Transistor Power Amplifiers in Hyperfrequences).  

National Technical Information Service (NTIS)

Methods to characterize the nonlinearities in hyperfrequency devices are studied showing that nonlinear transformation techniques are efficient to evaluate distorsions and intermodulation of GaAs MESFET power amplifiers. A computer program was developed t...

A. Loembe

1986-01-01

36

Gyrator employing field effect transistors  

NASA Technical Reports Server (NTRS)

A gyrator circuit of the conventional configuration of two amplifiers in a circular loop, one producing zero phase shift and the other producing 180 deg phase reversal is examined. All active elements are MOS field effect transistors. Each amplifier comprises a differential amplifier configuration with current limiting transistor, followed by an output transistor in cascode configuration, and two load transistors of opposite conductivity type from the other transistors. A voltage divider control circuit comprises a series string of transistors with a central voltage input to provide control, with locations on the amplifiers receiving reference voltages by connection to appropriate points on the divider. The circuit produces excellent response and is well suited for fabrication by integrated circuits.

Hochmair, E. S. (inventor)

1973-01-01

37

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

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

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

40

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)

2008-01-01

41

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

42

Computer aided design and fabrication of an X-band oscillator transistor  

Microsoft Academic Search

This paper describes the computer aided design and fabrication techniques used to realize an optimized X-band oscillator transistor. Transistor oscillator and amplifier performance data are presented.

J. M. Gladstone; P. T. Chen; P. Wang; S. Kakihana

1973-01-01

43

Temperature Compensation of Transistor Integrator.  

National Technical Information Service (NTIS)

It is shown that the temperature dependence of an inverted transistor can be very effectively used for temperature compensation. Conditions were derived for complete compensation of an integrator amplifier with emitter follower output and single-stage amp...

C. P. Wang

1964-01-01

44

Device and Circuit Codesign Strategy for Application to Low-Noise Amplifier Based on Silicon Nanowire MetalOxideSemiconductor Field Effect Transistors  

Microsoft Academic Search

In this study, a full-range approach from device level to circuit level design is performed for RF application of silicon nanowire (SNW) metal-oxide-semiconductor field effect transistors (MOSFETs). Both DC and AC analyses have been conducted to confirm the advantages of an SNW MOSFET over the conventional planar (CPL) MOSFET device having dimensional equivalence. Besides the intrinsic characteristic parameters, the extrinsic

Seongjae Cho; Hee-Sauk Jhon; Jung Hoon Lee; Se Hwan Park; Hyungcheol Shin; Byung-Gook Park

2010-01-01

45

Class E RF\\/microwave power amplifier: linear “equivalent” of transistor's nonlinear output capacitance, normalized design and maximum operating frequency vs. output capacitance  

Microsoft Academic Search

Previous studies led by the authors yield a maximum operating frequency value for a class E amplifier considering a linear capacitance shunting the device. This linearity also appears in most classical mathematical analyses published so far. This paper faces the problem of finding a linear equivalent capacitance (easy to handle) of the nonlinear voltage-dependent output capacitance of the semiconductor device.

Arturo Mediano; Pilar Molina; J. Navarro

2000-01-01

46

Cooled Low-Noise HEMT Microwave Amplifiers  

NASA Technical Reports Server (NTRS)

Prototype cooled low-noise microwave amplifiers based on high-electron-mobility transistors (HEMT's) considered as replacements for cooled ruby masers used as low-noise receiver-front-end amplifiers in communications, radio science, radar systems, radio astronomy, and telemetry. HEMT amplifier operates at 12 K, requires less cooling power and operates at lower cost with simpler, more-reliable cooling system.

Bautista, J. Javier; Ortiz, Gerardo G.; Duh, Kuanghann George

1992-01-01

47

The effects of high temperature and total dose gamma radiation on a power MOSFET (metal-oxide semiconductor field effect transistor) (N-channel) and an operational amplifier  

Microsoft Academic Search

Little data exists on the effects of high temperature (> 125°C) and\\/or total accumulated gamma doses exceeding 10 Megarad on electronic components. The results of a series of tests investigating these effects on an N-channel MOSFET and a dielectrically isolated operational amplifier are presented. The devices were exposed to high temperatures and high total dose radiation and a simultaneous combination

W. T. Wheelis; S. M. Luker

1987-01-01

48

Rise-time control in saturated amplifiers  

NASA Technical Reports Server (NTRS)

Inductor in transistor emitter circuit controls output rise time of saturated amplifier thereby reducing radiated noise and distortion in subsequent circuits. Device also improves current balancing in push/pull transformer circuits. Resulting circuits are self compensating for temperature.

Theall, C. E.

1980-01-01

49

A nonlinear macromodel of the bipolar integrated circuit operational amplifier for electromagnetic interference analysis  

Microsoft Academic Search

A nonlinear macromodel for the bipolar transistor integrated circuit operational amplifier is derived from the macromodel proposed by Boyle. The nonlinear macromodel contains only two nonlinear transistors in the input stage in a differential amplifier configuration. Parasitic capacitance effects are represented by capacitors placed at the collectors and emitters of the input transistors. The nonlinear macromodel is effective in predicting

G. K. C. Chen

1981-01-01

50

Solid State Amplifier Linearization Techniques for Interference Reduction in USAF Communications Systems.  

National Technical Information Service (NTIS)

The report describes the development of thr TRW Jo2009 linear power transistor and the design of a broad band UHF amplifier using these transistors. The amplifier uses two J02009 transistors with hybrid power splitting and summing techniques to combine th...

E. R. Moss R. DeBloois

1973-01-01

51

HEMT 60 GHz amplifier  

NASA Technical Reports Server (NTRS)

A high electron mobility transistor (HEMT) amplifier has been fabricated which exhibits 7.5 dB gain at 61 GHz. This result was obtained with a quarter-micrometre gate-length depletion-mode HEMT. Reduction of source-gate resistance and gate length are primarily responsible for this performance. The letter describes the materials and device processing technology developed for fabricating these devices.

Berenz, J.; Nakano, K.; Hsu, T.-I.; Goel, J.

1985-01-01

52

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

53

Cryogenic MMIC Low Noise Amplifiers  

NASA Technical Reports Server (NTRS)

Monolithic (MMIC) and discrete transistor (MIC) low noise amplifiers are compared on the basis of performance, cost, and reliability. The need for cryogenic LNA's for future large microwave arrays for radio astronomy is briefly discussed and data is presented on a prototype LNA for the 1 to 10 GZH range along with a very wideband LNA for the 1 to 60 GHz range.

Weinreb, S.; Gaier, T.; Fernandez, J.; Erickson, N.; Wielgus, J.

2000-01-01

54

Ion bipolar junction transistors  

PubMed Central

Dynamic control of chemical microenvironments is essential for continued development in numerous fields of life sciences. Such control could be achieved with active chemical circuits for delivery of ions and biomolecules. As the basis for such circuitry, we report a solid-state ion bipolar junction transistor (IBJT) based on conducting polymers and thin films of anion- and cation-selective membranes. The IBJT is the ionic analogue to the conventional semiconductor BJT and is manufactured using standard microfabrication techniques. Transistor characteristics along with a model describing the principle of operation, in which an anionic base current amplifies a cationic collector current, are presented. By employing the IBJT as a bioelectronic circuit element for delivery of the neurotransmitter acetylcholine, its efficacy in modulating neuronal cell signaling is demonstrated.

Tybrandt, Klas; Larsson, Karin C.; Richter-Dahlfors, Agneta; Berggren, Magnus

2010-01-01

55

Graphene transistors  

Microsoft Academic Search

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

Frank Schwierz

2010-01-01

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

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

58

Radiation Tolerance of GaAs Broadband Amplifier.  

National Technical Information Service (NTIS)

The response and degradation characteristics of microstripline GaAs junction field-effect transistor integrated microwave amplifiers were investigated in radiation environments. Permanent changes in electrical performance due to fluences of 5x 10 to the 1...

A. F. Behle R. Zuleeg

1973-01-01

59

A very low offset voltage operational amplifier using field programmable floating-gate technology  

Microsoft Academic Search

A very low offset voltage operational amplifier that can be field programmable is described. Offset reduction is achieved by programming two floating gate transistors that form an important part of a single-stage folded cascode amplifier. A novel programming method that requires just four additional pins and an LMS algorithm was used. Floating-gate transistors were programmed for a minimum offset voltage

Juan Iglesias-Rojas; Felipe Gomez-Castañeda; Jose Moreno-Cadenas

2010-01-01

60

4-Kbit Four-Transistor Dynamic RAM.  

National Technical Information Service (NTIS)

The design of a 64-word by 64-bit dynamic RAM is described. The RAM cell is implemented as a four-transistor dynamic cell. Sense amplifiers are used to reduce access time. Bootstrapped logic reduces power dissipation. Experimental results indicate a typic...

H. Walker

1983-01-01

61

Using Transistors in the Avalanche Mode.  

National Technical Information Service (NTIS)

A typical feature of the functioning of the transistor in an avalanche mode consists in the marked improvement in the high-frequency and amplifying properties owing to a reduction in the active width of the base, which occurs at high voltages. As a result...

V. D. Dyakonov

1969-01-01

62

Transistor Nonlinear Damage.  

National Technical Information Service (NTIS)

The report summarizes the study of radiation induced surface degradation of (1) discrete planar transistors and (2) of devices in a silicon hybrid array (bipolar transistors, MOSFETS, MOS capacitors). The study of planar transistors, resulted in determini...

L. L. Sivo

1972-01-01

63

BEC transistor  

NASA Astrophysics Data System (ADS)

In the past decade, considerable efforts have been spent developing BEC based devices for applications such as fundamental research, precision measurements, and quantum information technology. These devices, capable of complex functionality, may be constructed from simple building blocks. New atom-optical components will enable researchers to build more elaborate integrated devices. One of the most important components of microelectronics is the transistor. We are proposing a device that shows behavior reminiscent of a transistor, which enables one to control a large number of atoms with a smaller number. This device utilizes three atom traps where the atoms in the left act as the source in a field effect transistor, the atoms in the middle act as the gate, and the right trap is the drain. When the middle trap is empty, atoms cannot tunnel from the left through the middle and in to the right, because the chemical potential in the middle trap is sufficiently smaller than that in the left or right to block tunneling. If a small number of atoms are placed in the middle, the device switches enabling tunneling from the left to the right. This tunneling is due to the fact that atom-atom interactions increase the chemical potential in the middle trap and remove the energy mismatch. We show that the number of atoms tunneling into the right can be much larger than the number of controlling atoms in the middle. Thus, the three trap structure demonstrates both absolute and differential gain, and that it can be used as an atomic transistor.

Stickney, James; Anderson, Dana; Zozulya, Alex

2006-05-01

64

High-efficiency solid state power amplifier  

NASA Technical Reports Server (NTRS)

A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

Wallis, Robert E. (Inventor); Cheng, Sheng (Inventor)

2005-01-01

65

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.

2008-09-04

66

Wide-Temperature-Range Integrated Operational Amplifier  

NASA Technical Reports Server (NTRS)

A document discusses a silicon-on-insulator (SOI) complementary metal oxide/semiconductor (CMOS) integrated- circuit operational amplifier to be replicated and incorporated into sensor and actuator systems of Mars-explorer robots. This amplifier is designed to function at a supply potential less than or equal to 5.5 V, at any temperature from -180 to +120 C. The design is implemented on a commercial radiation-hard SOI CMOS process rated for a supply potential of less than or equal to 3.6 V and temperatures from -55 to +110 C. The design incorporates several innovations to achieve this, the main ones being the following: NMOS transistor channel lengths below 1 m are generally not used because research showed that this change could reduce the adverse effect of hot carrier injection on the lifetimes of transistors at low temperatures. To enable the amplifier to withstand the 5.5-V supply potential, a circuit topology including cascade devices, clamping devices, and dynamic voltage biasing was adopted so that no individual transistor would be exposed to more than 3.6 V. To minimize undesired variations in performance over the temperature range, the transistors in the amplifier are biased by circuitry that maintains a constant inversion coefficient over the temperature range.

Mojarradi, Mohammad; Levanas, Greg; Chen, Yuan; Kolawa, Elizabeth; Cozy, Raymond; Blalock, Benjamin; Greenwell, Robert; Terry, Stephen

2007-01-01

67

Offset reduction in operational amplifiers using floating gate technology and LMS algorithm  

Microsoft Academic Search

An offset reduction technique using floating gate technology and LMS algorithm is presented. Offset reduction in operational amplifiers is achieved by programming two floating gate transistors that form an important part of a single-stage folded cascode amplifier. Floating-gate transistors were programmed for a minimum offset voltage of ±25µV using 1.2µm CMOS process. Programmed operational amplifiers can be used in continuous-time

J. C. Iglesias-rojas; F. Gomez-castaneda; J. A. Moreno-cadenas

2011-01-01

68

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

69

Hydraulic Amplifier.  

National Technical Information Service (NTIS)

The proposed hydraulic amplifier differs from those already known for increasing accuracy, simplifying the design and ensuring the independence of the output parameter from a change in pressure and drainage head; the throttle valve in it is incorporated i...

A. A. Lyubimov E. D. Magner M. V. Shevyakov

1969-01-01

70

Gyromagnetron Amplifier.  

National Technical Information Service (NTIS)

Document describes a gyromagnetron amplifier for radiation at millimeter wavelengths comprising a tapered waveguide tube with longitudinally running vanes in the walls of the tube with the number of vanes chosen to coincide with a desired cyclotron harmon...

Y. Y. Lau L. R. Barnett

1983-01-01

71

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

72

A cooled 1- to 2-GHz balanced HEMT amplifier  

NASA Technical Reports Server (NTRS)

The design details and measurement results for a cooled L-band (1 to 2 GHz) balanced high electron mobility transistor (HEMT) amplifier are presented. The amplifier uses commercially available packaged HEMT devices (Fujitsu FHR02FH). At a physical temperature of 12 K, the amplifier achieves noise temperatures between 3 and 6 K over the 1 to 2 GHz band. The associated gain is approximately 20 dB.

Ortiz, Gerardo G.; Padin, Steven

1991-01-01

73

Note: A high dynamic range, linear response transimpedance amplifier.  

PubMed

We have built a high dynamic range (nine decade) transimpedance amplifier with a linear response. The amplifier uses junction-gate field effect transistors (JFETs) to switch between three different resistors in the feedback of a low input bias current operational amplifier. This allows for the creation of multiple outputs, each with a linear response and a different transimpedance gain. The overall bandwidth of the transimpedance amplifier is set by the bandwidth of the most sensitive range. For our application, we demonstrate a three-stage amplifier with transimpedance gains of approximately 10(9)?, 3 × 10(7)?, and 10(4)? with a bandwidth of 100 Hz. PMID:22380140

Eckel, S; Sushkov, A O; Lamoreaux, S K

2012-02-01

74

A high-speed clamped bit-line current-mode sense amplifier  

Microsoft Academic Search

A clamped bit-line current-mode sense amplifier that maintains a low-impedance fixed potential on the bit lines is introduced. Using a general model for active-drive memory cells that include the two-transistor (2T) and three-transistor (3T) dynamic cells and the four-transistor\\/two-resistor (4T-2R) and six-transistor (6T) static cells, the new sense amplifier is shown to have a response speed that is insensitive to

Travis N. Blalock; Richard C. Jaeger

1991-01-01

75

Method and apparatus for cascaded ground return amplifier  

US Patent & Trademark Office Database

A cascaded amplifier is integrated within an integrated circuit with a cascaded ground bus. The cascaded ground bus provides two ground points at opposite ends. Each amplifier ground of each amplifier stage couples to the ground wire there between. The cascaded ground bus substantially reduces the parasitic inductance in the emitter leg of each IC transistor within each amplifier. The lay out of the cascaded ground bus wire is tightly coupled to the lay out of the input wires so that their respective parasitic inductances are magnetically coupled together to form a mutual inductance. The mutual inductance effectively cancels the effect of the ground return inductance due to them being similar inductance values and having the same ground loop current flowing through them in opposite directions. The cascaded ground bus can be utilized in substantially all amplifier types including class A, B, C, D, BD, E, F, G, H, S and their variations and with substantially all transistor types used within amplifier stages including bipolar junction transistors, field effect transistors and their variants (i.e. PNP, NPN, MOSFET, NFET, PFET, JFET, MESFET, etc.). An IC cascaded amplifier with the cascaded ground bus can be utilized in a number of communication systems where amplification is needed including battery operated systems such as a transceiver of a portable cellular telephone.

2001-10-09

76

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

77

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, J.T.

1984-02-02

78

Differential Amplifier.  

National Technical Information Service (NTIS)

In an embodiment, a pair of push-pull amplifier stages are balanced with respect to ground. A pair of resistors are inserted between the cathode of the electron tube in each stage and ground. The A.C. potential variation across the load resistance of each...

T. R. Williams

1964-01-01

79

Optical Amplifier Using Nonlinear Nanodefect Cavity in Photonic Crystal  

NASA Astrophysics Data System (ADS)

We have proposed a new optical amplifier in a photonic crystal. The amplifier consists of a nonlinear nanodefect cavity and a cross waveguide. The input-output characteristics have been simulated for the amplifier with three- or four-port cross waveguide in a two-dimensional photonic crystal by the finite-difference time-domain method. In the amplifier, a signal light can be amplified by an energy transfer from a control light to the signal light at the nonlinear nano-defect cavity. The calculated amplification factor of the amplifier was 2.33× 104. When optical transistor was used with an amplifier with a three-port cross waveguide in a two-dimensional photonic crystal, the calculated switching rate, the on-off ratio and the amplification factor of the transistor were 12 Gbit/s, 1.95× 105 and 2.29× 104, respectively. The transistor can work well even under a low power input in the signal port and can be utilized as a small amplifier and an optical sensor with a fast response.

Kawashita, Yoshiyuki; Haraguchi, Masanobu; Okamoto, Hiroyuki; Fujii, Masamitsu; Fukui, Masuo

2006-10-01

80

A Transistorized Digital Computer.  

National Technical Information Service (NTIS)

The M-54 general-purpose transistorized digital computer is described. This computer is a modification of one of the first transistorized computer models developed at the Moscow 'Order of Lenin' Power Engineering Institute. This single-address machine is ...

I. A. Bashmakov V. S. Zubov V. A. Fedin T. I. Golubeva T. K. Rybakova

1968-01-01

81

Design of two-stage MOSFET-only operational amplifiers  

Microsoft Academic Search

In this work, the gate-to-bulk capacitance property of MOS transistors is employed to design high-speed two-stage operational amplifiers (opamp). Traditional design of two-stage opamps recommends MIM or PIP capacitors to avoid instability in closed-loop applications. In addition to area efficiency achieved by replacing these capacitors with MOS transistors, the integration of the opamp would become compatible with standard digital CMOS

Hamed Aminzadeh; Mohammad Danaie

2008-01-01

82

Multiplexer/amplifier test results for SP-100  

SciTech Connect

Multiplexer and amplifier systems must be designed with transistors that can perform satisfactorily over ten years to a total gamma dose of 120E6 rads and a total neutron fluence of 1.6E15 nvt for the SP-100 reactor system. Series of gamma and neutron tests have been completed to measure transistor degradation as a function of total dose, fluence, and temperature. Test results indicate that modest increases in temperature result in substantial improvement of transistor performance at a neutron flux of 8E8 n/cm{sup 2}/s. 2 refs., 3 figs.

King, D.B.; Luker, S.M. (Sandia National Labs., Albuquerque, NM (USA)); Ryan, R. (General Electric Co., San Jose, CA (USA))

1990-01-01

83

Tunnelling hot electron transfer amplifiers  

NASA Astrophysics Data System (ADS)

Significant advances were achieved in tunneling hot electron amplifiers and in the understanding of hot electron transport in the work funded by the contract and carried out by M. Heiblum and his co-workers. The results of this work are described in detail in nine papers that have been published in the open literature. (These papers are listed below as references 1-9 and copies of them are attached.) This report summarizes the principal results. There are three aspects of the work in which the results are particularly noteworthy: the demonstration of the first hot hole tunneling transistor and its use to study hot hole transport in GaAs; the successful fabrication of a hot electron 'THETA' transistor with a pseudomorphic InGaAs base which allowed high transistor gains (beta approx. = 30) to be achieved; and the conception and successful fabrication of a lateral hot electron device and its use to investigate ballistic, hot electron transport in a 2-dimensional electron gas in GaAs.

Kircher, C. J.

1993-10-01

84

Cryogenic Amplifier Based Receivers at Submillimeter Wavelengths  

NASA Technical Reports Server (NTRS)

The operating frequency of InP high electron mobility transistor (HEMT) based amplifiers has moved well in the submillimeter-wave frequencies over the last couple of years. Working amplifiers with usable gain in waveguide packages has been reported beyond 700 GHz. When cooled cryogenically, they have shown substantial improvement in their noise temperature. This has opened up the real possibility of cryogenic amplifier based heterodyne receivers at submillimeter wavelengths for ground-based, air-borne, and space-based instruments for astrophysics, planetary, and Earth science applications. This paper provides an overview of the science applications at submillimeter wavelengths that will benefit from this technology. It also describes the current state of the InP HEMT based cryogenic amplifier receivers at submillimeter wavelengths.

Chattopadhyay, Goutam; Reck, Theodore and; Schlecht, Erich; Lin, Robert; Deal, William

2012-01-01

85

Ultra-low-noise heterostructure field-effect transistor, millimeter-wave receivers.  

NASA Astrophysics Data System (ADS)

Recent developments in ultra-low-noise heterostructure field-effect transistor receiver technology for frequencies up to W-band are discussed. The following main topics are covered: noise and signal properties of heterostructure field-effect transistors (HFETs), also known as high-electron mobility transistors (HEMT's), at cryogenic temperatures, design and examples of the realization of wideband low-noise, cryogenically-coolable HFET amplifiers and receivers in the 20 to 100 GHz range, and a comparison of HFET receivers with SIS mixer/HFET IF amplifier receivers.

Pospieszalski, M. W.

86

A high-swing CMOS telescopic operational amplifier  

Microsoft Academic Search

A high-swing, high-performance CMOS telescopic operational amplifier is described. The high swing of the op-amp is achieved by employing the tail and current source transistors in the deep linear region. The resulting degradation in differential gain, common-mode rejection ratio (CMRR), and other amplifier characteristics are compensated by applying regulated-cascode differential gain enhancement and a replica-tail feedback technique. A prototype of

Kush Gulati; Hae-Seung Lee

1998-01-01

87

32GHz cryogenically cooled HEMT low-noise amplifiers  

Microsoft Academic Search

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

K. H. George Duh; William F. Kopp; Pin Ho; Pane-Chane Chao; Ming-Yih Ko; Phillip M. Smith; James M. Ballingall; J. Javier Bautista; Gerardo G. Ortiz

1989-01-01

88

A cooled 1-2 GHz balanced HEMT amplifier  

Microsoft Academic Search

The design details and measurement results for a cooled 1-GHz-bandwidth L-band high electron mobility transistor (HEMT) amplifier are presented. No facilities-were available for measuring low-temperature S parameters, but the HEMT noise parameters were measured at a physical temperature of 12 K. The absence of S-parameter information precluded the design of a feedback amplifier, so a balanced configuration was adopted. This

Stephen Padin; Gerardo G. Ortiz

1991-01-01

89

On 32GHz cryogenically cooled HEMT low-noise amplifiers  

Microsoft Academic Search

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

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

1988-01-01

90

Near-Field Thermal Transistor  

NASA Astrophysics Data System (ADS)

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 that 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; Biehs, Svend-Age

2014-01-01

91

30 GHz low-noise HEMT amplifier for satellite applications  

NASA Astrophysics Data System (ADS)

The development of a four-stage Ka-band low-noise amplifier using 0.25-micron gate-length HEMTs is discussed. A combination of the standard technology employed in solid-state microwave amplifiers and the conventional waveguide technology is utilized, while the electrical design principle is derived from a cryogenically cooled 20-HGz low-noise amplifier developed previously. The optimization procedure for the amplifier is carried out experimentally due to the accuracy and manufacturing tolerance limitations. The amplifier layout and transistor selection are described, and a breadboard model of the four-stage amplifier capable of a noise figure of 3.8 dB over the temperature range from 0 C to 40 C is presented.

Glandorf, Franz J.; Kueck, Peter

1990-11-01

92

Design, measurement and analysis of CMOS polysilicon TFT operational amplifiers  

Microsoft Academic Search

The small signal properties of polysilicon TFT opamps have been investigated in this paper. A method for the scaling of gm (transconductance) and gds (output conductance) has been proposed, facilitating their estimates for various transistors in operational amplifiers. The analysis of two CMOS opamps fabricated by a low temperature, glass compatible poly-Si TFT process is demonstrated in comparison to the

Hai-Gang Yang; Steve Fluxman; Carlo Reita; Piero Migliorato

1994-01-01

93

MMIC Amplifier Based Receivers for Earth Remote Sensing  

Microsoft Academic Search

We have developed amplifier based receivers using Indium Phosphide high electron mobility transistor (HEMT) monolithic microwave integrated circuit (MMIC) technology. These compact receivers are designed with atmospheric temperature and humidity sounding requirements in mind, operating at 100-140 GHz around the 118 GHz oxygen line and at 170-200 GHz near the 183 GHz water line. We have also developed a compact

Douglas E. Dawson; Todd Gaier; Sander Weinreb

2002-01-01

94

Compact, Single-Stage MMIC InP HEMT Amplifier  

NASA Technical Reports Server (NTRS)

A monolithic micro - wave integrated-circuit (MMIC) singlestage amplifier containing an InP-based high-electron-mobility transistor (HEMT) plus coplanar-waveguide (CPW) transmission lines for impedance matching and input and output coupling, all in a highly miniaturized layout as needed for high performance at operating frequencies of hundreds of gigahertz is described.

Pukala, David; Samoska, Lorene; Fung, King Man; Gaier, Todd; Deal, W. R.; Mei, Gerry; Radisic, Vesna; Lai, Richard

2008-01-01

95

Adaptively preserving power amplifier linearity under antenna mismatch  

Microsoft Academic Search

An adaptive method is proposed to preserve power amplifier linearity under severe antenna mismatch condition, as an alternative to an isolator. At high output power and mismatch conditions voltage clipping, due to collector voltage saturation of the bipolar power transistor, is demonstrated to be the main cause of distortion. Linearity degradation can be properly monitored by minimum voltage detection, which

Andre van Bezooijen; Christophe Chanlo; A. H. M. van Roermund

2004-01-01

96

Analysis and Design of a Gated Envelope Feedback Technique for Automatic Hardware Reconfiguration of RFIC Power Amplifiers, with Full On-Chip Implementation in Gallium Arsenide Heterojunction Bipolar Transistor Technology  

NASA Astrophysics Data System (ADS)

In this doctoral dissertation, the author presents the theoretical foundation, the analysis and design of analog and RF circuits, the chip level implementation, and the experimental validation pertaining to a new radio frequency integrated circuit (RFIC) power amplifier (PA) architecture that is intended for wireless portable transceivers. A method called Gated Envelope Feedback is proposed to allow the automatic hardware reconfiguration of a stand-alone RFIC PA in multiple states for power efficiency improvement purposes. The method uses self-operating and fully integrated circuitry comprising RF power detection, switching and sequential logic, and RF envelope feedback in conjunction with a hardware gating function for triggering and activating current reduction mechanisms as a function of the transmitted RF power level. Because of the critical role that RFIC PA components occupy in modern wireless transceivers, and given the major impact that these components have on the overall RF performances and energy consumption in wireless transceivers, very significant benefits stem from the underlying innovations. The method has been validated through the successful design of a 1.88GHz COMA RFIC PA with automatic hardware reconfiguration capability, using an industry renowned state-of-the-art GaAs HBT semiconductor process developed and owned by Skyworks Solutions, Inc., USA. The circuit techniques that have enabled the successful and full on-chip embodiment of the technique are analyzed in details. The IC implementation is discussed, and experimental results showing significant current reduction upon automatic hardware reconfiguration, gain regulation performances, and compliance with the stringent linearity requirements for COMA transmission demonstrate that the gated envelope feedback method is a viable and promising approach to automatic hardware reconfiguration of RFIC PA's for current reduction purposes. Moreover, in regard to on-chip integration of advanced PA control functions, it is demonstrated that the method is better positioning GaAs HBT technologies, which are known to offer very competitive RF performances but inherently have limited integration capabilities. Finally, an analytical approach for the evaluation of inter-modulation distortion (IMD) in envelope feedback architectures is introduced, and the proposed design equations and methodology for IMD analysis may prove very helpful for theoretical analyses, for simulation tasks, and for experimental work.

Constantin, Nicolas Gerard David

97

Biasing effect on improvement of linearity and efficiency of RF linear power amplifier  

Microsoft Academic Search

Based on bipolar junction transistor (BJT) modeling the theoretical analysis of biasing effect on improvement of linearity and efficiency of RF linear power amplifier (LPA) are introduced, according to these analysis and by using matlab curve fitting toolbox an analytical model for improvement of linearity and efficiency of RF linear power amplifiers (PAs) is introduced. This model simplifies the traditionally

Mazhar B. Tayel; Amir Al-Mslmany

2011-01-01

98

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

99

Accurate transient response model for automatic synthesis of high-speed operational amplifiers  

Microsoft Academic Search

This paper presents an accurate time-domain analysis of operational amplifiers' step response. Both slewing and linear settling phases are investigated in order to correct some discrepancies found in previous literature works. Moreover theoretical results are exploited developing a CAD tool for the automatic synthesis of high-gain high- speed operational amplifiers. Transistor level simulations are performed with MOS lev. 2 and

Cristiano Azzolini; P. Milanesi; Andrea Boni

2006-01-01

100

1,000 Watt Peak Pulsed Power Amplifier 960 MHz to 1215 MHz.  

National Technical Information Service (NTIS)

The purpose of this program was to develop a one kilowatt peak microwave power amplifier for broadband operation over the frequency range 960 MHz to 1215 MHz using a maximum of four output transistors in parallel, 250 watt peak power each. The amplifier w...

A. A. Tanielian J. R. Curtis W. E. Schaub

1976-01-01

101

32-GHz Cryogenically Cooled HEMT (High Electron Mobility Transitor) Low-Noise Amplifiers.  

National Technical Information Service (NTIS)

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 ou...

J. J. Bautista G. G. Ortiz K. H. G. Duh W. F. Kopp P. Ho

1988-01-01

102

4-8 GHz Low Noise Amplifiers using metamorphic HEMT Technology  

Microsoft Academic Search

This paper describes two metamorphic high electron mobility transistor (mHEMT) amplifiers with low noise in the frequency band 4-8 GHz. One amplifier contains the complete circuitry on a monolithic microwave integrated circuit (MMIC) chip and the other is configured with the input network on a low loss duroid substate together with an MMIC. The measurements at room temperature for the

Matthew Kelly; Iltcho Angelov; J. Piotr Starski; Niklas Wadefalk; Herbert Zirath

2006-01-01

103

Analysis and optimum design of impedance matching for Ka-Band cryogenic low noise amplifiers  

Microsoft Academic Search

High electron mobility transistors (HEMTs) and cryogenic cooling are widely employed in high gain and low noise millimeter-wave amplifiers. By using the temperature dependant model of HEMT, this paper further investigated the optimum impedance matching for low noise amplifiers (LNAs) to exhibit a significant improvement in noise and gain performance under cryogenic temperatures. One MMIC LNA covering 26-40 GHz frequency

Yang Hou; Ruming Wen; Lingyun Li; Hengrong Cui; Rong Qian; Xiaowei Sun

2009-01-01

104

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

105

A 2.3-GHz cryogenically cooled HEMT amplifier for DSS 13  

NASA Technical Reports Server (NTRS)

A prototype 2.3 GHz (S band) high electron mobility transistor (HEMT) amplifier/closed cycle refrigerator (CCR) system was installed in the DDS-13 feedcone, replacing the 2.3 GHz maser. The amplifier is cryogenically cooled to a physical temperature of 12 K and provides 31.5 K antenna system noise temperature and 29 dB of gain. The HEMT device used in the amplifier is a prototype.

Tanida, L.

1987-01-01

106

A 2.3-GHz cryogenically cooled HEMT amplifier for DSS 13  

NASA Astrophysics Data System (ADS)

A prototype 2.3 GHz (S band) high electron mobility transistor (HEMT) amplifier/closed cycle refrigerator (CCR) system was installed in the DDS-13 feedcone, replacing the 2.3 GHz maser. The amplifier is cryogenically cooled to a physical temperature of 12 K and provides 31.5 K antenna system noise temperature and 29 dB of gain. The HEMT device used in the amplifier is a prototype.

Tanida, L.

1987-11-01

107

Graphene microwave transistors on sapphire substrates  

NASA Astrophysics Data System (ADS)

We have developed metal-oxide graphene field-effect transistors (MOGFETs) on sapphire substrates working at microwave frequencies. For monolayers, we obtain a transit frequency up to ~80 GHz for a gate length of 200 nm and a maximum oscillation frequency of about ~3 GHz for this specific sample. Given the strongly reduced charge noise for nanostructures on sapphire, the high stability and high performance of this material at low temperature, our MOGFETs on sapphire are well suited for a cryogenic broadband low-noise amplifier.

Pallecchi, E.; Benz, C.; Betz, A. C.; Löhneysen, H. V.; Plaçais, B.; Danneau, R.

2011-09-01

108

MMIC HEMT Power Amplifier for 140 to 170 GHz  

NASA Technical Reports Server (NTRS)

A three-stage monolithic microwave integrated circuit (MMIC) power amplifier that features high-electron-mobility transistors (HEMTs) as gain elements is reviewed. This amplifier is designed to operate in the frequency range of 140 to 170 GHz, which contains spectral lines of several atmospheric molecular species plus subharmonics of other such spectral lines. Hence, this amplifier could serve as a prototype of amplifiers to be incorporated into heterodyne radiometers used in atmospheric science. The original intended purpose served by this amplifier is to boost the signal generated by a previously developed 164-GHz MMIC HEMT doubler and drive a 164-to-328-GHz doubler to provide a few milliwatts of power at 328 GHz.

Samoska, Lorene; Radisic, Vesna; Ngo, Catherine; Janke, Paul; Hu, Ming; Micovic, Miro

2003-01-01

109

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

110

Power booster audio amplifier  

Microsoft Academic Search

A novel power booster amplifier is based on a modified half-bridge topology using separated switches and a floating bridge capacitor. The power booster amplifier provides four times higher peak power at the loudspeaker than the peak power of a class-D amplifier using the same power supply. Total harmonic distortion and amplifier efficiency are similar to a class-D amplifier. A universal

Milan Prokin

2002-01-01

111

Soliton Tunneling Transistor  

Microsoft Academic Search

We report on a macroscopic version of the single-electron transistor (SET), which we call the soliton tunneling transistor (STT). The STT, consists of a gate capacitor coupled to a NbSe$_{3}$ crystal with a charge density wave (CDW). The current-voltage characteristic of an STT is periodically modulated by the gate voltage, as in the SET,except that the periodicity corresponds to a

J. H. Miller; Jr; G. Cardenas; A. Garcia; W. More; A. W. Beckwith; J. P. McCarten

2001-01-01

112

Graphene Nanoribbon Tunnel Transistors  

Microsoft Academic Search

A graphene nanoribbon (GNR) tunnel field-effect transistor (TFET) is proposed and modeled analytically. Ribbon widths between 3 and 10 nm are considered to effect energy bandgaps in the range of 0.46 to 0.14 eV. It is shown that a 5-nm ribbon width TFET can switch from on to off with only 0.1-V gate swing. The transistor achieves 800 muA\\/mum on

Qin Zhang; Tian Fang; Huili Xing; Alan Seabaugh; Debdeep Jena

2008-01-01

113

An x-band peeled HEMT amplifier  

NASA Technical Reports Server (NTRS)

A discrete peeled high electron mobility transistor (HEMT) device was integrated into a 10 GHz amplifier. The discrete HEMT device interconnects were made using photo patterned metal, stepping from the 10 mil alumina host substrate onto the 1.3 microns thick peeled GaAs HEMT layer, eliminating the need for bond wires and creating a fully integrated circuit. Testing of devices indicate that the peeled device is not degraded by the peel off step but rather there is an improvement in the quantum well carrier confinement. Circuit testing resulted in a maximum gain of 8.5 dB and a return loss minimum of -12 dB.

Young, Paul G.; Romanofsky, Robert R.; Alterovitz, Samuel A.; Smith, Edwyn D.

1993-01-01

114

Preventing Simultaneous Conduction In Switching Transistors  

NASA Technical Reports Server (NTRS)

High voltage spikes and electromagnetic interference suppressed. Power-supply circuit including two switching transistors easily modified to prevent simultaneous conduction by both transistors during switching intervals. Diode connected between collector of each transistor and driving circuit for opposite transistor suppresses driving signal to transistor being turned on until transistor being turned off ceases to carry current.

Mclyman, William T.

1990-01-01

115

Hybrid matrix amplifier  

DOEpatents

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

116

Hybrid matrix amplifier  

DOEpatents

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

117

A global operational amplifier with constant-gm input and output stage  

Microsoft Academic Search

The principle and design of a 3 V two-stage CMOS operational amplifier are described. A rail-to-rail input stage shows almost constant transconductance independent of the common mode input voltage range with global transistor operation region. This new technique does not make use of accurate current-voltage relations of MOS transistors. Hence it can be applicable to a simple linear relationship of

Il Kwon Chang; Jang Woo Park; Se Jun Kim; Kae Dal Kwack

1999-01-01

118

Optically Isolated Amplifier.  

National Technical Information Service (NTIS)

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-isolate...

C. J. Smith

1982-01-01

119

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

120

Boost bridge audio amplifier  

Microsoft Academic Search

The main difference in topology of a boost bridge amplifier and state-of-the-art class-D amplifier is in the connection of a loudspeaker between a power supply and a switching bridge. The boost bridge amplifier provides four times higher peak power at the loudspeaker than the power, which can be achieved by a class-D amplifier from the same power supply. Total harmonic

Milan Prokin

2001-01-01

121

Laser amplifier chain  

DOEpatents

A laser amplifier chain has a plurality of laser amplifiers arranged in a chain to sequentially amplify a low-power signal beam to produce a significantly higher-power output beam. Overall efficiency of such a chain is improved if high-gain, low efficiency amplifiers are placed on the upstream side of the chain where only a very small fraction of the total pumped power is received by the chain and low-gain, high-efficiency amplifiers are placed on the downstream side where a majority of pumping energy is received by the chain. 6 figs.

Hackel, R.P.

1992-10-20

122

Laser amplifier chain  

DOEpatents

A laser amplifier chain has a plurality of laser amplifiers arranged in a chain to sequentially amplify a low-power signal beam to produce a significantly higher-power output beam. Overall efficiency of such a chain is improved if high-gain, low efficiency amplifiers are placed on the upstream side of the chain where only a very small fraction of the total pumped power is received by the chain and low-gain, high-efficiency amplifiers are placed on the downstream side where a majority of pumping energy is received by the chain.

Hackel, Richard P. (Livermore, CA)

1992-01-01

123

A fully matched high linearity 2-W PHEMT MMIC power amplifier for 3.5 GHz applications  

Microsoft Academic Search

A 2-W monolithic microwave integrated circuit power amplifier, operating between 3.3 and 3.8GHz by implementing AlGaAs\\/InGaAs\\/GaAs pseudomorphic high electronic mobility transistor for the applications of wideband code division multiple access, wireless local loop, and multichannel multipoint distribution service, is demonstrated. This two-stage amplifier is designed to fully match 50? input and output impedances. With a dual-bias configuration, the amplifier possesses

Chen-Kuo Chu; Hou-Kuei Huang; Hong-Zhi Liu; Ray-Jay Chiu; Che-Hung Lin; Chih-Cheng Wang; Mau-Phon Houng; Yeong-Her Wang; Chuan-Chien Hsu; Wang Wu; Chang-Luen Wu; Chian-Sern Chang

2005-01-01

124

CMOS low-voltage operational amplifiers with constant-g m rail-to-rail input stage  

Microsoft Academic Search

Two 3.3-V operational amplifiers with constant-gm rail-to-rail input stage and rail-to-rail output stage are presented. The constant transconductance (gm) ensures a constant unity-gain frequency within the whole commonmode input range. Two new methods to control thegm are introduced. Both operational amplifiers use the same rail-to-rail output stage. The operational amplifiers have been integrated in a CMOS semicustom process with transistor

Ron Hogervorst; Remco J. Wiegerink; Peter A. L. De Jong; Jeroen Fonderie; Roelof F. Wassenaar; Johan H. Huijsing

1994-01-01

125

Low-noise cryogenic X-band amplifier using wet-etched hydrogen passivated InP HEMT devices  

Microsoft Academic Search

The performance of a cryogenically cooled X-band amplifier for the geodetic VLBI X-band (8.1-9.0 GHz) is presented. The amplifier incorporates hydrogen passivated InP devices with 0.2×200 ?m gate. A comparison of the noise performance with selected commercially available GaAs high electron mobility transistor (HEMT) devices of similar dimensions is presented. The InP amplifier shows lower noise temperature (Tn=4.8 K, NF=0.07

Isaac Lopez-Fernandez; Juan Daniel Gallego Puyol; Otte J. Homan; Alberto Barcia Cancio

1999-01-01

126

250 nm InP DHBT monolithic amplifiers with 4.8 dB gain at 324 GHz  

Microsoft Academic Search

An indium-phosphide (InP) double-heterojunction bipolar transistor (DHBT) based common-base monolithic power amplifier has been fabricated and has a measured small signal gain of 4.8 dB at 324 GHz. This is the highest frequency DHBT MMIC amplifier reported to date. The submillimeter-wave power amplifier MMIC incorporates microstrip transmission lines on a 10-mum thick layer of BCB dielectric. The thick BCB layer

Jonathan Hacker; Miguel Urteaga; Dino Mensa; Richard Pierson; Mike Jones; Zach Griffith; Mark Rodwell

2008-01-01

127

Accelerating the life of transistors  

NASA Astrophysics Data System (ADS)

Choosing small and medium power switching transistors of the NPN type in a 3DK set as the study object, the test of accelerating life is conducted in constant temperature and humidity, and then the data are statistically analyzed with software developed by ourselves. According to degradations of such sensitive parameters as the reverse leakage current of transistors, the lifetime order of transistors is about more than 104 at 100 °C and 100% relative humidity (RH) conditions. By corrosion fracture of transistor outer leads and other failure modes, with the failure truncated testing, the average lifetime rank of transistors in different distributions is extrapolated about 103. Failure mechanism analyses of degradation of electrical parameters, outer lead fracture and other reasons that affect transistor lifetime are conducted. The findings show that the impact of external stress of outer leads on transistor reliability is more serious than that of parameter degradation.

Haochun, Qi; Changzhi, Lü; Xiaoling, Zhang; Xuesong, Xie

2013-06-01

128

MMIC amplifier-based receivers for Earth remote sensing  

Microsoft Academic Search

We have developed amplifier based receivers using Indium Phosphide high electron mobility transistor (HEMT) monolithic microwave integrated circuit (MMIC) technology. These compact receivers are designed with atmospheric temperature and humidity sounding requirements in mind, operating at 100-125 GHz around the 118 GHz oxygen line, and at 160-185GHz near the 183 GHz water line, with average noise temperatures of 1600 and

Douglas E. Dawson; Todd C. Gaier; Sander Weinreb; Matthew A. Morgan; Mary Wells

2003-01-01

129

A Low-Noise Charge Sensitive Preamplifier for Semiconductor Detectors Using Paralleled Field-Effect-Transistors  

Microsoft Academic Search

The use of a 2N3823 or a 2N3819 (the Silex equivalent of the 2N3823) field-effect transistor (FET) has led to the design of an improved charge sensitive preamplifier. The amplifier has provisions for paralleling FET's in the input stage which gives considerable improvement in the resolution vs capacitance slope over single FET's. Measured resolution of the amplifier temperature was 0.53

K. F. Smith; J. E. Cline

1966-01-01

130

Cryogenically cooled K-band high electron mobility transistor receiver for radio astronomical observation  

Microsoft Academic Search

A K-band receiver using cooled high electron mobility transistor (HEMT) amplifiers was developed at the Nobeyama Radio Observatory. A remarkable reduction in receiver noise temperature, T(rec), was obtained when it was cooled down to cryogenic temperature. The lowest T(rec) of 75 K was obtained at 23.4 GHz. This low noise characteristic reveals that the cooled HEMT amplifier is promising as

T. Kasuga; R. Kawabe; M. Ishiguro; K. Yamada; H. Kurihara; M. Niori; Y. Hirachi

1987-01-01

131

Cryogenically cooled K-band high electron mobility transistor receiver for radio astronomical observation  

NASA Astrophysics Data System (ADS)

A K-band receiver using cooled high electron mobility transistor (HEMT) amplifiers was developed at the Nobeyama Radio Observatory. A remarkable reduction in receiver noise temperature, T(rec), was obtained when it was cooled down to cryogenic temperature. The lowest T(rec) of 75 K was obtained at 23.4 GHz. This low noise characteristic reveals that the cooled HEMT amplifier is promising as a sensitive receiver for radio astronomical observations.

Kasuga, T.; Kawabe, R.; Ishiguro, M.; Yamada, K.; Kurihara, H.

1987-03-01

132

45nm Transistor Reliability  

Microsoft Academic Search

It has been clear for a number of years that increasing transistor gate leakage with device scaling would ultimately necessitate an alternative to traditional SiON dielectrics with polysilicon gates. Material systems providing higher dielectric constants, and therefore allowing physically thicker dielectrics, have been the object of extensive research. Such high-k dielectrics, when combined with metal gate electrodes, have emerged as

Jeffrey Hicks

133

Field effect transistors  

Microsoft Academic Search

A patent is claimed for an invention relating to Metal Insulator Semiconductor Field Effect Transistors (MISFECTs) in which organic polymers are used as the semiconducting component. The FET has a gate electrode deposited on a substrate and separated from a semiconducting layer by an insulating layer, the semiconducting layer being provided with two terminals to allow passage of an electric

Philip Charles Allen; Richard Henry Friend; Jeremy Henly Burroughes

1988-01-01

134

Nanowire transistors without junctions  

Microsoft Academic Search

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

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

2010-01-01

135

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

136

Multipass optical parametric amplifier  

NASA Astrophysics Data System (ADS)

A compact, low-threshold, multipass optical parametric amplifier has been developed for the conversion of short-pulse (360-ps) 1064-nm Nd:YAG laser radiation into eye-safe 1572-nm radiation for laser ranging and radar applications. The amplifier had a threshold pump power of as low as 45 mu J , and at three to four times this threshold pump power the amplifier converted 30% of the input 1064-nm radiation into 1572-nm output radiation.

Jeys, T. H.

1996-08-01

137

The DARPA FLARE Program: Recent Advances in Ultra High Linearity RF Amplifiers  

Microsoft Academic Search

The DARPA Feedback Linearized Amplifier for RF Electronics (FLARE) Program has demonstrated the world's first microwave operational amplifier with record linearity through the use of strong negative feedback made possible by the large available gain-bandwidth product in state-of-the-art Indium Phosphide (InP) transistor technologies. The output third-order intercept point (OIP3) near 2 GHz is measured to be +51.4 dBm while consuming

Sanjay Raman; Tsu-Hsi Chang; Richard C. Eden; Steve Pappert

2008-01-01

138

2-6 GHz GaN MMIC Power Amplifiers for Electronic Warfare Applications  

Microsoft Academic Search

This paper presents two MMIC broadband high power amplifiers of 4 mm of periphery at the output stage in the frequency band 2-6 GHz. The amplifiers are based on Al-GaN\\/GaN high electron mobility transistor (HEMT) technology on SiC substrate. They have been fabricated in two different european foundries: SELEX Sistemi Integrati and QINETIQ. SELEX has a gate process technology of

M. Angeles Gonzalez-Garrido; Jesus Grajal; Pablo Cubilla; Antonio Cetronio; Claudio Lanzieri; Mike Uren

2008-01-01

139

Design and development of an S-band Low Noise Amplifier  

Microsoft Academic Search

This paper describes the design and development of a single stage Low Noise Amplifier (LNA) working at 3 GHz frequency. The single stage amplifier is designed by using commercially available p-HEMT, Filtronic (RFMD) FPD6836P70. The LNA makes use of plated through holes (PTH) to obtain good high frequency grounding of the transistor. The prototype LNA is tested at room temperature,

S. K. Giri; Chayanika Bose

2010-01-01

140

A cryogenic GaAs HBT microwave amplifier and its application to a superconductor digital IC  

Microsoft Academic Search

The first microwave GaAs HBT (heterojunction bipolar transistor) amplifier results at 4.2 K are benchmarked. The amplifier nominal gain is 6 dB and is measured from 130 MHz to 10 GHz at fixture temperatures of 295 K, 77 K, and 4.2 K. The maximum gain variation over temperature was found to be about 2 dB. Maximum gain occurred at temperatures

K. W. Kobayashi; J. H. Kobayashi; M. Leung; A. K. Oki; M. Matloubian; S. Chan; D. C. Streit

1993-01-01

141

Hybrid semiconductive\\/high temperature superconductive Ku-band oscillator and amplifier MICs  

Microsoft Academic Search

The design, fabrication, and testing of hybrid semiconductive\\/high-temperature superconductive (HTSC) Ku-band microwave integrated circuits (MICs) operating at cryogenic temperatures are described. The first cooled feedback oscillators using GaAs FET monolithic microwave integrated circuit (MMIC) los-noise amplifiers for gain and a high-Q TlBaCaCuO linear resonator for stabilization is presented together with a low-noise high electron mobility transistor (HEMT) amplifier using TlBaCaCuO

J. W. Smuk; M. G. Stubbs; J. S. Wight

1992-01-01

142

An 8.4GHz cryogenically cooled HEMT amplifier for DSS 13  

Microsoft Academic Search

A prototype 8.4 GHz (X-band) high electron mobility transistor (HEMT) amplifier\\/closed cycle refrigerator system was installed in the Deep Space Station 13 feedcone in August 1987. The amplifier is cryogenically cooled to a physical temperature of 12 K and provides 31 K antenna noise temperature (zenith) and 35 dB of gain at a frequency of 8.2 to 8.6 GHz. Antenna

L. Tanida

1988-01-01

143

2GHz band cryogenically-cooled GaN HEMT amplifier for mobile base station receivers  

Microsoft Academic Search

This paper presents a 2-GHz band gallium nitride (GaN) high electron mobility transistor (HEMT) amplifier cryogenically cooled to 60 K as a part of the cryogenic receiver front-end (CRFE) for mobile base station receivers. The GaN HEMT amplifier attains the output power of 3 W and the maximum power added efficiency of 62% with a 50 V drain bias for

Shoichi Narahashi; Yasunori Suzuki; Toshio Nojima

2007-01-01

144

2GHz Band Cryogenically-Cooled GaN HEMT Amplifier for Mobile Base Station Receivers  

Microsoft Academic Search

This paper presents a 2-GHz band gallium nitride (GaN) high electron mobility transistor (HEMT) amplifier cryogenically cooled to 60 K as a part of the cryogenic receiver front-end (CRFE) for mobile base station receivers. The GaN HEMT amplifier attains the output power of 3 W and the maximum power added efficiency of 62% with a 50 V drain bias for

Shoichi Narahashi; Yasunori Suzuki; Toshio Nojima

2007-01-01

145

Amplifiers and Active Systems  

NSDL National Science Digital Library

Created by Tony R. Kuphaldt, this chapter of All About Circuit's third volume on Semiconductors describes amplifiers and active devices. The chapter is divided into seven sections: From electric to electronic, Active versus passive devices, Amplifiers, Amplifier gain, Decibels, Absolute dB scales, and Attenuators. Each section has clear illustrations and a concise, bulleted review of what was covered at the end. There is also a link to the All About Circuits forums, where contributors and other visitors discuss the material presented. This is an excellent resource for educators in physics and electronic engineering classrooms to introduce lessons or units on amplifiers.

Kuphaldt, Tony R.

2008-07-03

146

Proton induced damage in JFET transistors and charge preamplifiers on high-resistivity silicon  

Microsoft Academic Search

The results discussed in this paper are relevant to junction field effect transistors and JFET based charge sensitive amplifiers fabricated in a detector compatible process. Such structures were irradiated with 27 MeV protons to evaluate the suitability of the technology for space applications and high energy physics experiments from the standpoint of radiation tol- erance. The process investigated in this

G. F. Dalla Betta; M. Manghisoni; L. Ratti; V. Re; Valeria Speziali; Gianluca Traversi; Andrea Candelori

2003-01-01

147

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

148

GaAs FET amplifiers reach millimeter waves  

NASA Astrophysics Data System (ADS)

The introduction of a GaAs FET transistor amplifier capable of over 20-dB gain at frequencies in the range from 26.5 to 40 GHz promises to provide new possibilities for system designers. The 26.5-to-40-GHz GaAs FET amplifier offers a new, compact alternative to bulky, expensive Gunn diode amplifiers with interstage broadband ferrite isolators or costly TWT amplifiers with MTBFs of only 5,000 to 10,000 hrs. For currently produced GaAs FET devices in the 18-to-26.5-GHz range, the MTBF is 20,000 to 40,000 hrs. The reliability of GaAs is expected to show itself at frequencies above 26.5 GHz. The Gunn diode, TWT, and GaAs FET amplifiers are compared in a table. The 26.5-to-40-GHz amplifier presently under development is designed with cascadable MIC modules. Low-noise 40GHz GaAs FET amplifiers are suitable as receiving preamplifiers which can be directly mounted on compact antennas, thereby increasing the effectiveness of monopulse direction-finding systems.

Rosenberg, J. C.; Policky, G. J.; Osbrinke, N. K.

1982-06-01

149

Parametric resonance in nanoelectromechanical single electron transistors.  

PubMed

We show that the coupling between single-electron charging and mechanical motion in a nanoelectromechanical single-electron transistor can be utilized in a novel parametric actuation scheme. This scheme, which relies on a periodic modulation of the mechanical resonance frequency through an alternating source-drain voltage, leads to a parametric instability and emergence of mechanical vibrations in a limited range of modulation amplitudes. Remarkably, the frequency range where instability occurs and the maximum oscillation amplitude, depend weakly on the damping in the system. We also show that a weak parametric modulation increases the effective quality factor and amplifies the system's response to the conventional actuation that exploits an AC gate signal. PMID:21375279

Midtvedt, Daniel; Tarakanov, Yury; Kinaret, Jari

2011-04-13

150

Nonmagnetic semiconductor spin transistor  

NASA Astrophysics Data System (ADS)

We propose a spin transistor using only nonmagnetic materials that exploits the characteristics of bulk inversion asymmetry (BIA) in (110) symmetric quantum wells. We show that extremely large spin splittings due to BIA are possible in (110) InAs/GaSb/AlSb heterostructures, which together with the enhanced spin decay times in (110) quantum wells demonstrates the potential for exploitation of BIA effects in semiconductor spintronics devices. Spin injection and detection is achieved using spin-dependent resonant interband tunneling and spin transistor action is realized through control of the electron spin lifetime in an InAs lateral transport channel using an applied electric field (Rashba effect). This device may also be used as a spin valve, or a magnetic field sensor.

Hall, K. C.; Lau, Wayne H.; Gündo?du, K.; Flatté, Michael E.; Boggess, Thomas F.

2003-10-01

151

High voltage power transistor development  

NASA Technical Reports Server (NTRS)

Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

Hower, P. L.

1981-01-01

152

Terahertz detection and emission by field-effect transistors  

NASA Astrophysics Data System (ADS)

The concept of THz detection based on excitation of plasma waves in two-dimensional electron gas in Si FETs is one of the most attractive ones, as it makes possible the development of the large-scale integrated devices based on a conventional microelectronic technology including on-chip antennas and readout devices integration. In this work we report on investigations of Terahertz detectors based on low-cost silicon technology field effect transistors and asymmetric unit cell double grating gate field effect transistor. Double-grating-gate field-effect transistors have a great potential as terahertz detectors. This is because the double grating gate serves not only for carrier density tuning but also as an efficient THz radiation coupler. In this paper, we present characterization of these transistors using high magnetic fields. Low and high magnetic field data are used to determine the electron mobility and electron concentration, respectively, in different parts of the transistor channel. We show that detectors, consisting of a coupling antenna and a n-MOS field effect transistor as rectifying element, are efficient for THz detection and imaging. We demonstrate that in the atmospheric window around 300 GHz, these detectors can achieve a record noise equivalent power below 10 pW/Hz0.5 and responsivity above 90 kV/W once integrated with on-chip amplifier. We show also that they can be used in a very wide frequency range: from ~0.2 THz up to 1.1 THz. THz detection by Si FETs paves the way towards high sensitivity silicon technology based focal plane arrays for THz imaging.

Knap, Wojciech; Dyakonova, Nina V.; Schuster, Franz; Coquillat, Dominique; Teppe, Frédéric; Giffard, Benoît; But, Dmytro B.; Golenkov, Oleksander G.; Sizov, Fedor F.; Watanabe, Takayuki; Tanimoto, Youichi; Otsuji, Taiichi

2012-10-01

153

Scaling of Nanowire Transistors  

Microsoft Academic Search

This paper considers the scaling of nanowire transistors to 10-nm gate lengths and below. The 2-D scale length theory for a cylindrical surrounding-gate MOSFET is reviewed first, yielding a general guideline between the gate length and the nanowire size for acceptable short-channel effects. Quantum confinement of electrons in the nanowire is discussed next. It gives rise to a ground-state energy

Bo Yu; Lingquan Wang; Yu Yuan; Peter M. Asbeck; Yuan Taur

2008-01-01

154

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

155

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

156

Reverberation Controlled Gain Amplifier.  

National Technical Information Service (NTIS)

The amplifier is used in underwater echo-ranging apparatus associated with a homing-type torpedo. A signal amplifier is provided which automatically adjusts its sensitivity-time characteristic according to the rate of reverberation decoy of the signal ret...

J. W. Flowers E. J. Wade

1964-01-01

157

FGMOS-based NMC-RC frequency compensation differential amplifier for low power low voltage applications  

Microsoft Academic Search

This paper presents how to add flexibility to reduce the overall power consumption in a CMOS operational amplifier by replacing few MOS transistors with floating gate MOSFET (FGMOS). The disadvantages of doing this are also discussed. The performance of the proposed circuit using unity gain bandwidth (GBW) and slew rate (SR) as figure of merit is presented. The Nested Miller

A. Attaran; M. Moghavvemi; S. S. Jamuar

2012-01-01

158

A novel slew-rate enhancement technique for one-stage operational amplifiers  

Microsoft Academic Search

An efficient technique to improve the slew rate of one stage op-amps is introduced and verified. It operates by enhancing the output current by almost an order of magnitude without increasing the supply current under static or small signal conditions. The technique is only requires the addition of two transistors to conventional one-stage operational amplifier

J. Ramirez-Angulo

1996-01-01

159

High efficiency broadband linear push-pull power amplifiers using linearity augmentation  

Microsoft Academic Search

A method for improving the linearity and efficiency performance of Class AB push-pull power amplifiers is described in which the process of passive linearity augmentation is applied to correct the input signal current to the power transistors and to reduce the effects of crossover distortion, producing low intermodulation distortion products up to the 1 dB compression point. The method also

Chris Trask

2002-01-01

160

Development of GaN Based Microwave Power Amplifier for X Band Applications.  

National Technical Information Service (NTIS)

The feasibility of utilizing the GaN/AlGaN material system in the development of high power amplifiers for X-band frequencies and above was investigated. The GaN based heterojunction field effect transistor (HFET) on SiC shows remarkable power density at ...

K. W. Alt K. L. Wang

2000-01-01

161

Some characteristic features of the construction of the amplifying channel for working with semiconductor detectors in the charged particle energy spectrometer. [noise minimization at preamplifier input  

NASA Technical Reports Server (NTRS)

A transistorized spectrometric amplifier with a shaper is reported that selects the shape of the frequency characteristic of the amplifying channel for which the primary frequency spectrum of the signal will pass, but where the noise spectrum is limited to the maximum. A procedure is presented for selecting the shaping circuits and their inclusion principles.

Kuzyuta, E. I.

1974-01-01

162

HEMT Amplifiers and Equipment for their On-Wafer Testing  

NASA Technical Reports Server (NTRS)

Power amplifiers comprising InP-based high-electron-mobility transistors (HEMTs) in coplanar-waveguide (CPW) circuits designed for operation at frequencies of hundreds of gigahertz, and a test set for onwafer measurement of their power levels have been developed. These amplifiers utilize an advanced 35-nm HEMT monolithic microwave integrated-circuit (MMIC) technology and have potential utility as local-oscillator drivers and power sources in future submillimeter-wavelength heterodyne receivers and imaging systems. The test set can reduce development time by enabling rapid output power characterization, not only of these and similar amplifiers, but also of other coplanar-waveguide power circuits, without the necessity of packaging the circuits.

Fung, King man; Gaier, Todd; Samoska, Lorene; Deal, William; Radisic, Vesna; Mei, Xiaobing; Lai, Richard

2008-01-01

163

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

164

Gyrotron Travelling-Wave Amplifier.  

National Technical Information Service (NTIS)

An apparatus for amplifying coherent radiation at millimeter and submillimeter wavelengths includes the combination of a travelling-wave-tube cyclotron-maser-amplifier structure and a magnetron-injection electron gun. The amplifier structure includes a fa...

V. L. Granatstein P. Sprangle A. T. Drobot

1978-01-01

165

Fundamentals of Electronics. Volume 4. Receiver Circuit Applications.  

National Technical Information Service (NTIS)

Contents: Solid state power supplies; Two junction transistors; Receiver principles; Transistor RF amplifiers; Transistor oscillators; Transistor mixers and converters; Transistor IF amplifiers; Transistor detectors; Transistor audio amplifiers; Electron ...

1965-01-01

166

Superconducting Field-Effect Transistors  

NASA Technical Reports Server (NTRS)

Devices offer switching speeds greater than semiconducting counterparts. High-Tc superconducting field-effect transistors (SUPEFETs) investigated for use as electronic switches in delay-line-type microwave phase shifters. Resemble semiconductor field-effect transistors in some respects, but their operation based on different principle; namely, electric-field control of transition between superconductivity and normal conductivity.

Bhasin, Kul; Romanofsky, Robert R.; Tabib-Azar, Massood

1995-01-01

167

Terahertz heterodyne detection with silicon field-effect transistors  

NASA Astrophysics Data System (ADS)

We report on the detection of electromagnetic radiation at 0.65 THz by silicon field-effect transistors operated in heterodyne mode. Aiming at terahertz imaging with numerous pixels in a focal-plane array, we explore the improvement of the dynamic range achieved over power detection when the local-oscillator (LO) power is distributed quasioptically onto all detectors. These consist of resonantly antenna-coupled complementary metal-oxide-semiconductor transistors with a gate length of 0.25 ?m, and each has an integrated voltage amplifier. With a LO power of 2 ?W per detector, the noise-equivalent power amounts to 8 fW/Hz, leading to an estimated improvement of the dynamic range by 29 dB.

Glaab, Diana; Boppel, Sebastian; Lisauskas, Alvydas; Pfeiffer, Ullrich; Öjefors, Erik; Roskos, Hartmut G.

2010-01-01

168

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

169

32-GHz cryogenically cooled HEMT low-noise amplifiers  

NASA Astrophysics Data System (ADS)

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 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.

Duh, K. H. George; Kopp, William F.; Ho, Pin; Chao, Pane-Chane; Ko, Ming-Yih; Smith, Phillip M.; Ballingall, James M.; Bautista, J. Javier; Ortiz, Gerardo G.

1989-08-01

170

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 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.

Duh, K. H. George; Kopp, William F.; Ho, Pin; Chao, Pane-Chane; Ko, Ming-Yih; Smith, Phillip M.; Ballingall, James M.; Bautista, J. Javier; Ortiz, Gerardo G.

1989-01-01

171

On 32-GHz cryogenically cooled HEMT low-noise amplifiers  

NASA Astrophysics Data System (ADS)

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.

1988-11-01

172

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

173

An 8.4-GHz cryogenically cooled HEMT amplifier for DSS 13  

NASA Technical Reports Server (NTRS)

A prototype 8.4 GHz (X-band) high electron mobility transistor (HEMT) amplifier/closed cycle refrigerator system was installed in the Deep Space Station 13 feedcone in August 1987. The amplifier is cryogenically cooled to a physical temperature of 12 K and provides 31 K antenna noise temperature (zenith) and 35 dB of gain at a frequency of 8.2 to 8.6 GHz. Antenna system noise temperature is less than 50 K from 7.2 to 9.4 MHz. The low noise HEMT amplifier system is intended for use as a radio astronomy or space communications receiver front end.

Tanida, L.

1988-01-01

174

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

175

Integratable nanowire transistors.  

PubMed

We report a structure to control nanowire location and growth direction and demonstrate top-gated, metal-oxide-semiconductor, field-effect transistors (MOSFETs) using this structure. The nanowires wereengineered to grow against an oxide surface of a (001), silicon-on-insulator substrate, enabling straightforward fabrication of MOSFETs exhibiting an Io/Ioff ratio approximately 104 and a subthreshold slope of approximately 155 mV/decade. Though nanowires were engineered to grow in (110) directions, the nanowires still grew by the addition of {111) planes. PMID:19367850

Quitoriano, Nathaniel J; Kamins, Theodore I

2008-12-01

176

Fully relayed regenerative amplifier  

DOEpatents

A regenerative laser apparatus and method using the optical relay concept to maintain high fill factors, to suppress diffraction effects, and to minimize phase distortions in a regenerative amplifier.

Glass, Alexander J. (Berkeley, CA) [Berkeley, CA

1981-01-01

177

CGE Rod Amplifier Modules.  

National Technical Information Service (NTIS)

The performance and development history of the neodymium glass laser rod amplifiers in use at NRL on the Pharos II laser system is reviewed. The impact of possible future modifications is assessed. (Author)

J. M. McMahon

1978-01-01

178

Distributed sleep transistors network for power reduction  

Microsoft Academic Search

Sleep transistors are effective to reduce dynamic and leakage power. The cluster-based design was proposed to reduce the sleep transistor area by clustering gates to minimize the simultaneous switching current per cluster and then inserting a sleep transistor per cluster. In the paper, we propose a novel distributed sleep transistor network (DSTN), and show that DSTN is intrinsically better than

Changbo Long; Lei He

2003-01-01

179

Sleep transistor sizing in power gating designs  

Microsoft Academic Search

Power gating is effective for reducing leakage power. Previously, a distributed sleep transistors network (DSTN) was proposed to reduce the sleep transistor area by connecting all the virtual ground lines together to minimize the maximum instantaneous current (MIC) through sleep transistors. In this paper, we propose methodologies for determining the size of sleep transistors of the DSTN structure considering charge-balancing

De-Shiuan Chiou; Yu-Ting Chen; Da-Cheng Juan; Shih-Chieh Chang

2007-01-01

180

Distributed sleep transistor network for power reduction  

Microsoft Academic Search

Sleep transistors are effective to reduce dynamic and leakage power. The cluster-based design was proposed to reduce the sleep transistor area by clustering gates to minimize the simultaneous switching current per cluster and then inserting a sleep transistor per cluster. In the paper, we propose a novel distributed sleep transistor network (DSTN), and show that DSTN is intrinsically better than

Changbo Long; Lei He

2003-01-01

181

Distributed sleep transistor network for power reduction  

Microsoft Academic Search

Sleep transistors are effective to reduce leakage power during standby modes. The cluster-based design was proposed to save sleep transistor area by clustering gates to minimize the simultaneous switching current per cluster and inserting a sleep transistor per cluster. In this paper, we propose a novel distributed sleep transistor network (DSTN), and show that DSTN is intrinsically better than the

Changbo Long; Lei He

2004-01-01

182

Superfunctions for amplifiers  

NASA Astrophysics Data System (ADS)

An amplifier is characterized by its transfer function T, which expresses the dependence of the output signal on the input signal. This signal may be related to power, intensity, energy of a pulse, or its fluence, or any similar physical quantity. The internal structure of the amplified signal (e.g., its spectral content, polarization, temporal behavior, and spatial distribution) is not taken into account. The amplifier is considered to be spatially homogeneous and uniformly pumped. The transfer function is supposed to be known (measured in an experiment). The problem of reconstruction of the behavior of the signal inside the amplifier is formulated. For a given transfer function T, the evolution of the signal inside is interpreted as the superfunction F, satisfying the transfer equation F( z + 1) T(F(z)), where z is of coordinate along the propagation direction, while the length of the amplifier is used as a unit of measurement. (For simplicity, distances are measured in units of the length of the amplifier.) Two examples of realistic transfer function T are considered; they correspond to amplification of continuous wave and to amplification of pulses. In these examples, the transfer function and the distribution of the signal along the amplifier can be expressed in terms of special functions. The iterative procedure is suggested as a general method of reconstructing the signal along the amplifier, if neither the transfer function T, nor the superfunction F can be expressed with a simple combination of special functions. The examples show that the iterations converge to a physically meaningful solution. This method is expected to be useful for the characterization of laser materials from the measurement of the transfer function of a bulk sample.

Kouznetsov, Dmitrii

2013-07-01

183

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

184

Wideband Raman Amplifiers  

NASA Astrophysics Data System (ADS)

This chapter describes designs and experiments that apply the Raman effect to wideband amplifiers (WBAs). In the context of this chapter, wideband corresponds to a bandwidth of approximately 50 to 100 nm or more. We start by explaining the need for WBAs, and briefly review some of the key enabling technologies for wideband systems. Section 14.2 describes several approaches for WBA, including the erbium-doped fiber amplifier (EDFA) and Raman amplifier combinations as well as all-Raman amplifiers. Section 14.3 summarizes the advantages and challenges of the all-Raman approach, the focus of this chapter. Section 14.4 identifies the key physical principles that need to be considered in the design of all-Raman WBAs. Then, perhaps the most important section of this chapter, Section 14.5 describes engineering design rules for construction of all-Raman WBAs that satisfy gain and noise figure performance requirements of typical long-haul and ultra-long-haul fiber-optic transmission systems. Several WBA experiments that use either EDFA/Raman amplifier combinations or all-Raman amplifiers are illustrated in Section 14.6, and exemplary wideband system experiments are described in Section 14.7. Finally, we summarize and conclude the chapter in Section 14.8.

Islam, Mohammed N.; De Wilde, Carl; Kuditcher, Amos

185

Microwave field effect transistor  

NASA Astrophysics Data System (ADS)

Electrodes of a high power, microwave field effect transistor are substantially matched to external input and output networks. The field effect transistor includes a metal ground plane layer, a dielectric layer on the ground plane layer, a gallium arsenide active region on the dielectric layer, and substantially coplanar spaced source, gate, and drain electrodes having active segments covering the active region. The active segment of the gate electrode is located between edges of the active segments of the source and drain electrodes. The gate and drain electrodes include inactive pads remote from the active segments. The pads are connected directly to the input and output networks. The source electrode is connected to the ground plane layer. The space between the electrodes and the geometry of the electrodes extablish parasitic shunt capacitances and series inductances that provide substantial matches between the input network and the gate electrode and between the output network and the drain electrode. Many of the devices are connected in parallel and share a common active region, so that each pair of adjacent devices shares the same source electrodes and each pair of adjacent devices shares the same drain electrodes. The gate electrodes for the parallel devices are formed by a continuous stripe that extends between adjacent devices and is connected at different points to the common gate pad.

Huang, Ho-Chung

1989-06-01

186

Correlation impedance in transistors at high injection  

NASA Astrophysics Data System (ADS)

It is shown that the correlation impedance Rcor of a p+- n- p transistor at high injection and low frequencies is given as R cor = 2( {? p}/{? n})( {k T}/{q IEp}) , which is small for silicon transistors. For n+- p- n transistors under the same conditions R cor = 2( {? n}/{? p})( {k T}/{q IEP}) , which is large for silicon transistors. This strong asymmetry between p+- n- p and n+- p- n silicon transistors should be measurable.

Van der Ziel, A.

1983-09-01

187

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

188

Cryogenic instrumentation for fast current measurement in a silicon single electron transistor  

NASA Astrophysics Data System (ADS)

We present a realization of high bandwidth instrumentation at cryogenic temperatures and for dilution refrigerator operation that possesses advantages over methods using radio frequency single electron transistor or transimpedance amplifiers. The ability for the low temperature electronics to carry out faster measurements than with room temperature electronics is investigated by the use of a phosphorous-doped single electron transistor. A single shot technique is successfully implemented and used to observe the real-time decay of a quantum state. A discussion on various measurement strategies is presented and the consequences on electron heating and noise are analyzed.

Ferrus, T.; Hasko, D. G.; Morrissey, Q. R.; Burge, S. R.; Freeman, E. J.; French, M. J.; Lam, A.; Creswell, L.; Collier, R. J.; Williams, D. A.; Briggs, G. A. D.

2009-08-01

189

Photoconductivity measurements of single-walled carbon nanotube field effect transistors  

NASA Astrophysics Data System (ADS)

Photoconductivity measurements are performed on carbon nanotube field effect transistors. Carbon nanotubes are grown on SiO2/Si substrate by patterned chemical vapor deposition using ethanol as carbon source. Next, electron beam lithography, metal deposition, and liftoff processes are performed to form source and drain electrodes. The Si substrate is used as a back-gate in these devices. Wavelength tunable Ti:sapphire laser is focused onto the sample with an objective lens, and the laser spot is scanned with a steering mirror. A lock-in amplifier is used to detect the photoconductivity signal of carbon nanotube field effect transistors.

Murai, T.; Yasukochi, S.; Moritsubo, S.; Shimada, T.; Chiashi, S.; Murakami, Y.; Maruyama, S.; Kato, Y. K.

2011-03-01

190

Laser amplifier and method  

DOEpatents

Laser amplifiers and methods for amplifying a laser beam are disclosed. A representative embodiment of the amplifier comprises first and second curved mirrors, a gain medium, a third mirror, and a mask. The gain medium is situated between the first and second curved mirrors at the focal point of each curved mirror. The first curved mirror directs and focuses a laser beam to pass through the gain medium to the second curved mirror which reflects and recollimates the laser beam. The gain medium amplifies and shapes the laser beam as the laser beam passes therethrough. The third mirror reflects the laser beam, reflected from the second curved mirror, so that the laser beam bypasses the gain medium and return to the first curved mirror, thereby completing a cycle of a ring traversed by the laser beam. The mask defines at least one beam-clipping aperture through which the laser beam passes during a cycle. The gain medium is pumped, preferably using a suitable pumping laser. The laser amplifier can be used to increase the energy of continuous-wave or, especially, pulsed laser beams including pulses of femtosecond duration and relatively high pulse rate. 7 figs.

Backus, S.; Kapteyn, H.C.; Murnane, M.M.

1997-07-01

191

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

NASA Astrophysics Data System (ADS)

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?cm2?V-1?s-1, current modulation >106 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.

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

2012-11-01

192

Analog Electronics: Basic Circuits of Operational Amplifiers  

NSDL National Science Digital Library

This site offers a set of interactive operational amplifiers (OAs) simulators with detailed lessons and basic circuit schematics (including theory). The Java applets provided include an inverting amplifier, summing amplifier, difference amplifier, differentiator, and integrator circuit amplifier.

2009-11-02

193

Settling-time-oriented design procedure for two-stage amplifiers with current-buffer Miller compensation  

Microsoft Academic Search

A novel design procedure for two-stage operational amplifiers (op-amps) with current-buffer Miller compensation (CBMC) is proposed. The method is based on equations which relate both bias current and aspect ratio of transistors to the main amplifier parameters. The important innovation of the procedure is the definition of a systematic strategy to achieve the desired settling time by performing the op-amp

ANDREA PUGLIESE; FRANCESCO AMOROSO; GREGORIO CAPPUCCINO; GIUSEPPE COCORULLO

2008-01-01

194

A 1.6 GHz switch mode power amplifier with continuous-time bandpass delta-sigma modulator  

Microsoft Academic Search

A continuous-time bandpass delta-sigma modulator (CT BDSM) is designed and fabricated in a SiGe bipolar transistor technology with a transit frequency of 200 GHz. The modulator can be tuned in its center frequency from 1.55 GHz up to 2.45 GHz for mobile base station applications. To drive a GaN high power amplifier a driver amplifier is presented using a complementary

Manfred Berroth; Martin Schmidt; Stefan Heck; Alexander Braeckle; Markus Groezing

2009-01-01

195

A 174 W high-efficiency GaN HEMT power amplifier for W-CDMA base station applications  

Microsoft Academic Search

AlGaN\\/GaN high electron mobility transistors (HEMTs) have been developed for current-collapse-free operation at high drain bias voltages. The newly designed single-chip GaN HEMT amplifier for W-CDMA base station applications achieves a record CW output power of 150 W with a high power-added efficiency (PAE) of 54% at 2.1 GHz. The amplifier, combined with a digital pre-distortion (DPD) system, also demonstrates

K. Joshin; T. Kikkawa; H. Hayashi; T. Maniwa; S. Yokokawa; M. Yokoyama; N. Adachi; M. Takikawa

2003-01-01

196

Analysis of a class E tuned power amplifier with non-linear parasitic capacitance, using genetic algorithm  

Microsoft Academic Search

At the frequencies above 900 MHz, the nonlinear parasitic capacitance of the transistor will be the majority of the needed parallel capacitance of a class E amplifier. Using the Genetic Algorithm and Runge-Kutta Method, this paper analyses the class E amplifier with a small DC-feed inductance and a nonlinear parallel capacitance. The effects caused by these two non-ideal elements are

Y. Wang; B. X. Gao

1999-01-01

197

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.

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

2013-01-01

198

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

199

High transconductance organic electrochemical transistors  

NASA Astrophysics Data System (ADS)

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.

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.

2013-07-01

200

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

201

Gate-enclosed NMOS transistors  

NASA Astrophysics Data System (ADS)

In order to quantitatively compare the design cost and performance of various gate styles, NMOS transistors with two-edged, annular and ring gate layouts were designed and fabricated by a commercial 0.35 ?m CMOS process. By comparing the minimum W/L ratios and transistor areas, it was found that either the annular layout or its ring counterpart incurs a higher area penalty that depends on the W/L ratio of the transistor to be designed. Furthermore, by comparing the output and transfer characteristics of the transistors and analyzing the popular existing methods for extracting the effective W/L ratio, it was shown that the mid-line approximation for annular NMOS could incur an error of more than 10%. It was also demonstrated that the foundry-provided extraction tool needs significant adaptation when being applied to the enclosed-gate transistors, since it is targeted only toward the two-edged transistor. A simple approach for rough extraction of the W/L ratio for the ring-gate NMOS was presented and its effectiveness was confirmed by the experimental results with an error up to 8%.

Xue, Fan; Ping, Li; Wei, Li; Bin, Zhang; Xiaodong, Xie; Gang, Wang; Bin, Hu; Yahong, Zhai

2011-08-01

202

Ultrasensitive biomolecular assays with amplifying nanowire FET biosensors  

NASA Astrophysics Data System (ADS)

In this paper, we review our recent development and validation of the ultrasensitive electronic biomolecular assays enabled by our novel amplifying nanowire field-effect transistor (nwFET) biosensors. Our semiconductor nwFET biosensor platform technology performs extreme proximity signal amplification in the electrical domain that requires neither labeling nor enzymes nor optics. We have designed and fabricated the biomolecular assay prototypes and developed the corresponding analytical procedures. We have also confirmed their analytical performance in quantitating key protein biomarker in human serum, demonstrating an ultralow limit of detection and concurrently high output current level for the first time.

Chui, Chi On; Shin, Kyeong-Sik; Mao, Yufei

2013-09-01

203

Multipass amplifiers of POLARIS  

NASA Astrophysics Data System (ADS)

Advanced high intensity laser matter interaction experiments always call for optimized laser performance. In order to further enhance the POLARIS laser system, operational at the University of Jena and the Helmholtz-Institute Jena, in particular its energy, bandwidth and focusability, new amplifier technologies have been developed and are reported here. Additionally, existing sections were considerably improved. A new multi-pass amplification stage, which is able to replace two currently used ones, was developed in close collaboration with the MPQ (Garching). The new basic elements of this amplifier are well homogenized pump modules and the application of a successive imaging principle. By operating the amplifier under vacuum conditions a top hat beam profile with an output energy of up to 1.5 J per pulse is foreseen. The already implemented POLARIS amplifier A4 was further improved by adapting an advanced method for the homogenization of the multi-spot composed pump profile. The new method comprises a computer-based evolutionary algorithm which optimizes the position of the different spots regarding its individual size, shape and intensity. The latter allowed a better homogenization of the POLARIS near field profile.

Keppler, S.; Wandt, C.; Hornung, M.; Bödefeld, R.; Kessler, A.; Sävert, A.; Hellwing, M.; Schorcht, F.; Hein, J.; Kaluza, M. C.

2013-05-01

204

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

205

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

206

Properties and Applications of Varistor-Transistor Hybrid Devices  

NASA Astrophysics Data System (ADS)

The nonlinear current-voltage characteristics of a varistor device are modified with the help of external agents, resulting in tuned varistor-transistor hybrid devices with multiple applications. The substrate used to produce these hybrid devices belongs to the modified iron titanate family with chemical formula 0.55FeTiO3·0.45Fe2O3 (IHC45), which is a prominent member of the ilmenite-hematite solid-solution series. It is a wide-bandgap magnetic oxide semiconductor. Electrical resistivity and Seebeck coefficient measurements from room temperature to about 700°C confirm that it retains its p-type nature for the entire temperature range. The direct-current (DC) and alternating-current (AC) properties of these hybrid devices are discussed and their applications identified. It is shown here that such varistor embedded ceramic transistors with many interesting properties and applications can be mass produced using incredibly simple structures. The tuned varistors by themselves can be used for current amplification and band-pass filters. The transistors on the other hand could be used to produce sensors, voltage-controlled current sources, current-controlled voltage sources, signal amplifiers, and low-band-pass filters. We believe that these devices could be suitable for a number of applications in consumer and defense electronics, high-temperature and space electronics, bioelectronics, and possibly also for electronics specific to handheld devices.

Pandey, R. K.; Stapleton, William A.; Sutanto, Ivan; Scantlin, Amanda A.; Lin, Sidney

2014-05-01

207

The measurement of alkaline phosphatase at nanomolar concentration within 70 s using a disposable microelectrochemical transistor.  

PubMed

We report a new approach to the measurement of alkaline phosphatase concentration based on the use of a disposable poly(aniline) microelectrochemical transistor. The measurement is carried out in a two cell configuration in which the poly(aniline) microelectrochemical transistor operates in acid solution and is connected to the alkaline buffer solution containing the analyte by a salt bridge. Disposable microelectrochemical transistors were reproducibly fabricated by electrochemical deposition of poly(aniline) onto photolithographically fabricated gold microband arrays. Using these devices alkaline phosphatase was detected by employing p-aminophenyl phosphate as the substrate for the enzyme and using glucose and glucose oxidase to recycle the p-aminophenol generated upon enzyme catalysed hydrolysis of the phosphate. Recycling the p-aminophenol with glucose and glucose oxidase amplified the detection of alkaline phosphatase approximately tenfold. Using this approach we obtain linear calibration curves for alkaline phosphatase up to 5 nM within 70 s on single use devices. PMID:15219247

Astier, Y; Bartlett, P N

2004-08-01

208

Total Temperature Probe Buffer Amplifier.  

National Technical Information Service (NTIS)

The elimination of undesirable thermally induced changes of electrical characteristics of signal components is accomplished three operational amplifier circuits. The first operational amplifier provides electrical power to a system critical component and ...

W. E. Ott

1984-01-01

209

A pH sensor with a double-gate silicon nanowire field-effect transistor  

NASA Astrophysics Data System (ADS)

A pH sensor composed of a double-gate silicon nanowire field-effect transistor (DG Si-NW FET) is demonstrated. The proposed DG Si-NW FET allows the independent addressing of the gate voltage and hence improves the sensing capability through an application of asymmetric gate voltage between the two gates. One gate is a driving gate which controls the current flow, and the other is a supporting gate which amplifies the shift of the threshold voltage, which is a sensing metric, and which arises from changes in the pH. The pH signal is also amplified through modulation of the gate oxide thickness.

Ahn, Jae-Hyuk; Kim, Jee-Yeon; Seol, Myeong-Lok; Baek, David J.; Guo, Zheng; Kim, Chang-Hoon; Choi, Sung-Jin; Choi, Yang-Kyu

2013-02-01

210

Paper field effect transistor  

NASA Astrophysics Data System (ADS)

In this paper we report the use of a sheet of cellulose fiber-based paper as the dielectric layer used in oxide based semiconductor thin film field-effect transistors (FETs). In this new approach we are using the cellulose fiber-based paper in an "interstrate" structure since the device is build on both sides of the cellulose sheet. Such hybrid FETs present excellent operating characteristics such as high channel saturation mobility (>30 cm2/Vs), drain-source current on/off modulation ratio of approximately 104, near-zero threshold voltage, enhancement n-type operation and sub-threshold gate voltage swing of 0.8 V/decade. The cellulose fiber-based paper FETs characteristics have been measured in air ambient conditions and present good stability. The obtained results outpace those of amorphous Si TFTs and rival with the same oxide based TFTs produced on either glass or crystalline silicon substrates. The compatibility of these devices with large-scale/large-area deposition techniques and low cost substrates as well as their very low operating bias delineates this as a promising approach to attain high-performance disposable electronics like paper displays, smart labels, smart packaging, RFID and point-of-care systems for self analysis in bio-applications, among others.

Fortunato, E.; Correia, Nuno; Barquinha, Pedro; Costa, Cláudia; Pereira, Luís; Gonçalves, Gonçalo; Martins, Rodrigo

2009-02-01

211

Thermal transistor: Heat flux switching and modulating  

Microsoft Academic Search

Thermal transistor is an efficient heat control device which can act as a heat switch as well as a heat modulator. In this paper, we study systematically one-dimensional and two-dimensional thermal transistors. In particular, we show how to improve significantly the efficiency of the one-dimensional thermal transistor. The study is also extended to the design of two-dimensional thermal transistor by

Wei Chung Lo; Lei Wang; Baowen Li

2008-01-01

212

Metamorphic materials for indium arsenide transistors  

Microsoft Academic Search

To improve on both the high frequency and low-power aspects of the III-V semiconductor microwave transistor (by definition, the microwave transistor operates at frequencies above 1 GHz), InAs or a related high indium content alloy is incorporated in the base layer of the heterojunction bipolar transistor (HBT) and the channel layer of the high electron mobility transistor (HEMT). These devices

Atif M. Noori

2006-01-01

213

Proton-induced damage in JFET transistors and charge preamplifiers on high-resistivity silicon  

Microsoft Academic Search

The results discussed in this paper are relevant to junction field effect transistors (JFETs) and JFET-based charge sensitive amplifiers fabricated in a detector compatible process. Such structures were irradiated with 27 MeV protons to evaluate the suitability of the technology for space applications and high-energy physics experiments from the standpoint of radiation tolerance. The process investigated in this work, originally

G. F. D. Betta; Massimo Manghisoni; Lodovico Ratti; Valerio Re; Valeria Speziali; Gianluca Traversi; Andrea Candelori

2004-01-01

214

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

215

Ultrahigh speed modulation-doped field-effect transistors: a tutorial review  

Microsoft Academic Search

A tutorial review on the modulation-doped field-effect transistor (MODFET) and its application to ultra-low-noise, medium-power, and ultra-wide-band traveling-wave amplifiers as well as ultra-high-speed digital logic circuits is presented. It is believed that with further advances in material growth and device scaling significant improvements in cutoff frequencies, switching speed, noise, and power will be achieved in the near future

L. D. Nguyen; LAWRENCE E. LARSON; UMESH K. MISHRA

1992-01-01

216

Amplifying genetic logic gates.  

PubMed

Organisms must process information encoded via developmental and environmental signals to survive and reproduce. Researchers have also engineered synthetic genetic logic to realize simpler, independent control of biological processes. We developed a three-terminal device architecture, termed the transcriptor, that uses bacteriophage serine integrases to control the flow of RNA polymerase along DNA. Integrase-mediated inversion or deletion of DNA encoding transcription terminators or a promoter modulates transcription rates. We realized permanent amplifying AND, NAND, OR, XOR, NOR, and XNOR gates actuated across common control signal ranges and sequential logic supporting autonomous cell-cell communication of DNA encoding distinct logic-gate states. The single-layer digital logic architecture developed here enables engineering of amplifying logic gates to control transcription rates within and across diverse organisms. PMID:23539178

Bonnet, Jerome; Yin, Peter; Ortiz, Monica E; Subsoontorn, Pakpoom; Endy, Drew

2013-05-01

217

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

218

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

219

Longitudinal space charge amplifier  

NASA Astrophysics Data System (ADS)

Longitudinal space charge (LSC) driven microbunching instability in electron beam formation systems of X-ray FELs is a recently discovered effect hampering beam instrumentation and FEL operation. The instability was observed in different facilities in infrared and visible wavelength ranges. In this paper we propose to use such an instability for generation of vacuum ultraviolet (VUV) and X-ray radiation. A typical longitudinal space charge amplifier (LSCA) consists of few amplification cascades (drift space plus chicane) with a short undulator behind the last cascade. If the amplifier starts up from the shot noise, the amplified density modulation has a wide band, on the order of unity. The bandwidth of the radiation within the central cone is given by inverse number of undulator periods. A wavelength compression could be an attractive option for LSCA since the process is broadband, and a high compression stability is not required. LSCA can be used as a cheap addition to the existing or planned short-wavelength FELs. In particular, it can produce the second color for a pump-probe experiment. It is also possible to generate attosecond pulses in the VUV and X-ray regimes. Some user experiments can profit from a relatively large bandwidth of the radiation, and this is easy to obtain in LSCA scheme. Finally, since the amplification mechanism is broadband and robust, LSCA can be an interesting alternative to self-amplified spontaneous emission free electron laser (SASE FEL) in the case of using laser-plasma accelerators as drivers of light sources.

Schneidmiller, E. A.; Yurkov, M. V.

2013-05-01

220

Helical Fiber Amplifier  

SciTech Connect

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

221

Saturated Operational Amplifier  

NSDL National Science Digital Library

This animated gif illustrates the changing voltages when an operational amplifier (op-amp) becomes saturated. This animation would be useful for visually respresenting Finley's law. Voltages and parts of the circuit of this 3-D animated gif are highlighted with different colors. Current is displayed by green arrows indicating directional flow. The animation requires a Web browser or other video player software capable of displaying gif animations.Other 3-D Circuit Animations can be seen here.

2009-11-27

222

Bio-organic field effect transistors  

Microsoft Academic Search

This paper reports on the use of new DNA-based biopolymers as the semiconducting layer in field effect transistors. Thin-film field effect transistor (FET) structures are fabricated with two different DNA-biopolymers as semiconductor layers, and two different field effect transistor structures are studied. Current voltage characteristics of the FETs show that the devices are operating in depletion mode.

Carrie M. Bartsch; Guru Subramanyam; James G. Grote; Kristi M. Singh; Rajesh R. Naik; Birendra Singh; Niyazi S. Sariciftci

2007-01-01

223

Programmable, automated transistor test system  

NASA Technical Reports Server (NTRS)

A programmable, automated transistor test system was built to supply experimental data on new and advanced power semiconductors. The data will be used for analytical models and by engineers in designing space and aircraft electric power systems. A pulsed power technique was used at low duty cycles in a nondestructive test to examine the dynamic switching characteristic curves of power transistors in the 500 to 1000 V, 10 to 100 A range. Data collection, manipulation, storage, and output are operator interactive but are guided and controlled by the system software.

Truong, L. V.; Sundburg, G. R.

1986-01-01

224

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

225

Beyond G-band : a 235 GHz InP MMIC amplifier  

NASA Technical Reports Server (NTRS)

We present results on an InP monolithic millimeter- wave integrated circuit (MMIC) amplifier having 10-dB gain at 235 GHz. We designed this circuit and fabricated the chip in Northrop Grumman Space Technology's (NGST) 0.07- m InP high electron mobility transistor (HEMT) process. Using a WR3 (220-325 GHz) waveguide vector network analyzer system interfaced to waveguide wafer probes, we measured this chip on-wafer for -parameters. To our knowledge, this is the first time a WR3 waveguide on-wafer measurement system has been used to measure gain in a MMIC amplifier above 230 GHz.

Dawson, Douglas; Samoska, Lorene; Fung, A. K.; Lee, Karen; Lai, Richard; Grundbacher, Ronald; Liu, Po-Hsin; Raja, Rohit

2005-01-01

226

Cryogenic Design of the Deep Space Network Large Array Low-Noise Amplifier System  

NASA Astrophysics Data System (ADS)

This article describes the cryogenic design and performance of a prototype low-noise amplifier (LNA) system for the Deep Space Network (DSN) Large Array task. The system is used to cool a dual-frequency feed system equipped with high-electron mobility transistor (HEMT) low-noise amplifiers and the associated support electronics. The LNA/feed system operates at a temperature under 18 K. The system is designed to be manufactured at minimum cost. The design considerations, including the cryocooler to be used, vacuum system, microwave interconnects, mechanical components, and radiation shielding, are discussed.

Britcliffe, M. J.; Hanson, T. R.; Franco, M. M.

2004-05-01

227

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

228

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

229

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

230

Noise Minimization of MOSFET Input Charge Amplifiers Based on and Models  

Microsoft Academic Search

The optimization of the noise performance of integrated complementary metal-oxide semiconductor (CMOS) charge amplifiers is studied in detail considering accurate 1\\/f noise modeling for the input metal-oxide semiconductor field-effect transistor (MOSFET) biased in a strong inversion-saturation region. This paper aims to generalize and correct previously published analyses which have been based on two limiting and sometimes not applicable assumptions: a

Giuseppe Bertuccio; Stefano Caccia

2009-01-01

231

Improvement of Intermodulation Distortion Asymmetry Characteristics With Wideband Microwave Signals in High Power Amplifiers  

Microsoft Academic Search

This paper presents the improvement techniques of intermodulation-distortion asymmetries with wide carrier-spacing signals in L\\/S-band high power amplifiers. We proposed a novel circuit technique to directly connect LC series resonant circuits to the gate and drain electrodes of the transistor die in a package for baseband terminations with a wide frequency range. By applying this circuit technique to a 28-V

Isao Takenaka; Kohji Ishikura; Hidemasa Takahashi; Kouichi Hasegawa; Kazunori Asano; Naotaka Iwata

2008-01-01

232

Miller compensation using current buffers in fully differential CMOS two-stage operational amplifiers  

Microsoft Academic Search

Several Miller compensation schemes using a current buffer in series with the compensation capacitor to modify the right-half-plane zero in fully differential two-stage CMOS operational amplifiers are analyzed. One scheme uses a current mirror as a current buffer, while the rest use a common-gate transistor as a current buffer. The gain transfer functions are derived for each topology, and approximate

Paul J. Hurst; Stephen H. Lewis; John P. Keane; Farbod Aram; Kenneth C. Dyer

2004-01-01

233

An overview of feed-forward design techniques for high-gain wideband operational transconductance amplifiers  

Microsoft Academic Search

In this paper, feed-forward techniques are revised and used for the design of high-frequency operational transconductance amplifiers (OTA). For the same power consumption and similar transistor dimensions, the two- and three-path folded-cascode OTA's present both smaller settling error and faster response as compared to the typical folded-cascode topology. Also, a no-capacitor feed-forward (NCFF) compensation which uses a high-frequency pole-zero doublet

Bharath Kumar Thandri; José Silva-martinez

2006-01-01

234

Advances on GaN based switch mode amplifiers for communication applications  

Microsoft Academic Search

This paper presents the design and implementation of a switch mode power amplifier as a building block for a purely digital transmitter chain for communication applications using high-power Gallium Nitride (GaN) monolithic microwave integrated circuits (MMICs) with high electronic mobility transistors (HEMTs). For square-wave excitation the measured output power and drain efficiency are 5 W and 64 %, respectively, enabling

Ulf Schmid; Rolf Reber; Sebastien Chartier; Wilfried Grabherr; Ralf Leberer; Martin Oppermann

2011-01-01

235

Bias Power Supply Design for a Cryogenic HEMT Low Noise Amplifier  

Microsoft Academic Search

High Electronic Mobility Transistors (HEMT) are widely used in high sensitivity (low noise) radio astronomy receivers. Cooling a HEMT-based amplifier to 15K decreases the noise temperature by a factor of ten (and increases gain by about 3dB) compared to room temperature values. But only under the specific bias condition, the HEMT can obtain the optimal low noise, high gain and

Jiang Xu; Zheng-Wen Sun

2008-01-01

236

Cryogenic indium-phosphide HEMT low-noise amplifiers at V-band  

Microsoft Academic Search

Indium-phosphide (InP) high electron-mobility transistors potentially have the lowest noise at frequencies below 100 GHz, especially when cryogenically cooled. We have designed monolithically integrated InP millimeter-wave low-noise amplifiers (LNAs) for the European Space Agency (ESA) science Planck mission. The Planck LNA's design goal for noise temperature is 35 K at the ambient temperature of 20 K. The operation bandwidth is

J. M. Tanskanen; P. Kangaslahti; H. Ahtola; P. Jukkala; T. Karttaavi; M. Lahdes; J. Varis; J. Tuovinen

2000-01-01

237

Compact InP HBT Power Amplifiers Using Integrated Thick BCB Dielectrics  

Microsoft Academic Search

An indium-phosphide (InP) double-heterojunction bipolar transistor (DHBT) process for compact millimeter-wave power amplifier MMICs has been developed with integrated 15 mum thick layers of BCB dielectric. The thick BCB layers provide low-loss millimeter-wave transmission lines with much smaller dimensions compared to conventional microstrip placed directly on the semiconductor substrate. A single layer BCB process with two metal layers is used

J. B. Hacker; Wonill Ha; C. Hillman; M. Urteaga; R. Pierson; B. Brar

2007-01-01

238

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

239

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

240

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

241

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

242

Tunable Graphene Single Electron Transistor  

Microsoft Academic Search

We report electronic transport experiments on a graphene single electron transistor. The device consists of a graphene island connected to source and drain electrodes via two narrow graphene constrictions. It is electrostatically tunable by three lateral graphene gates and an additional back gate. The tunneling coupling is a strongly nonmonotonic function of gate voltage indicating the presence of localized states

C. Stampfer; E. Schurtenberger; F. Molitor; J. Güttinger; T. Ihn; K. Ensslin

2008-01-01

243

Microwave Silicon Permeable Base Transistor.  

National Technical Information Service (NTIS)

Silicon permeable base transistors (SiPBTs) have been fabricated, exhibiting a maximum available gain at 2 GHz of 11 dB and a 6 dB/octave decrement leading to a maximum frequency of oscillation (fmax) of 10 GHz. These SiPBTs differ in structural detail fr...

D. D. Rathman N. P. Economou D. J. Silversmith R. W. Mountain S. M. Cabral

1982-01-01

244

Charge separation for bipolar transistors  

Microsoft Academic Search

The effect of net positive oxide trapped charge and surface recombination velocity on excess base current in BJTs (bipolar junction transistors) is identified. Although the interaction of these two radiation-induced defects is physically complex, simple approaches for estimating these quantities from measured BJT characteristics are presented. The oxide charge is estimated using a transition voltage in the plot of excess

S. L. Kosier; R. D. Schrimpf; R. N. Nowlin; D. M. Fleetwood; M. Delaus; R. L. Pease; W. E. Combs; A. Wei; F. Chai

1993-01-01

245

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

246

Camel Gate Field Effect Transistors.  

National Technical Information Service (NTIS)

An alternative field effect transistor (FET) structure to the junction FET (JFET) and the metal-semiconductor FET (MESFET), the camel gate FET (CAMFET), is described. This device uses the voltage-variable depletion width of a camel disode for modulating t...

R. E. Thorne

1983-01-01

247

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

248

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

249

Terahertz wave parametric amplifier.  

PubMed

The importance of terahertz (THz) wave techniques has been demonstrated in various fields, and the range of applications is now expanding rapidly. However, the practical implementation of THz science to solve the real-world problems is restricted due to the lack not only of convenient high power THz wave emitters and sensitive detectors but also of efficient quasi-optical active devices such as amplifiers. In this work, we demonstrate the direct amplification of THz waves in room temperature using magnesium oxide-doped lithium niobate (MgO:LiNbO3) crystals as the nonlinear gain medium. The input THz wave is injected as a seed beam along with the pump beam into the nonlinear crystal and it is amplified by the optical parametric process. We report gain in excess of 30 dB with an input THz pulse energy of less than 1 pJ. We believe that this demonstration will contribute to the convenience and further applicability of THz frequency techniques. PMID:24690860

Tripathi, Saroj R; Taira, Yuusuke; Hayashi, Shin'ichiro; Nawata, Kouji; Murate, Kousuke; Minamide, Hiroaki; Kawase, Kodo

2014-03-15

250

Optical absorptions of polyfluorene transistors  

NASA Astrophysics Data System (ADS)

Conjugated polymers are a promising class of materials for organic electronics. While the progress in device performance is impressive, the basics of charge transport still pose many open questions. Specifically, conduction at the comparatively rough polymer-polymer interface in an all-polymer field-effect transistor is expected to be different from a sharp interface with an inorganic dielectric, such as silicon dioxide. In this work, charge modulation spectroscopy (CMS) is used to study the optical absorptions in the presence of charges in situ in the transistor structure. This allows direct observation of the charge carriers in the operational device via their spectroscopic signature; the technique is by design very sensitive to the properties of the semiconductor-dielectric interface. The semiconducting copolymer poly( 9,9' -dioctyl-fluorene-co-bithiophene) (F8T2) is incorporated into a top-gate thin-film transistor structure with a polymer dielectric layer deposited by spin coating and inkjet-printed polymer electrodes. A prominent charge-induced absorption at 1.65eV is observed as well as a shoulder at 1.3eV and a tail extending toward the absorption edge. The bias dependence of the CMS signature confirms that intermixing of the polymer layers is minimal, as expected from the excellent transistor characteristics. Polarization-dependent CMS measurements on aligned transistors show that the main feature at 1.65eV is strongly polarized whereas the shoulder is unpolarized. This observation, as well as further experimental evidence, lead to the conclusion that while the main absorption is attributable to the intrinsic, polaronic absorption in F8T2, the shoulder is likely to originate from a defect state.

Deng, Yvonne Y.; Sirringhaus, Henning

2005-07-01

251

Sensor Amplifier for the Venus Ground Ambient  

NASA Technical Reports Server (NTRS)

Previous Venus Landers employed high temperature pressure vessels, with thermally protected electronics, to achieve successful missions, with a maximum surface lifetime of 127 minutes. Extending the operating range of electronic systems to the temperatures (480 C) and pressures (90 bar) of the Venus ground ambient would significantly increase the science return of future missions. Toward that end, the current work describes the innovative design of a sensor preamplifier, capable of working in the Venus ground ambient and designed using commercial components (thermionic vacuum tubes, wide band gap transistors, thick film resistors, advanced high temperature capacitors, and monometallic interfaces) To identify commercial components and electronic packaging materials that are capable of operation within the specified environment, a series of active devices, passive components, and packaging materials were screened for operability at 500C, assuming a 10x increase in the mission lifetime. In addition. component degradation as a function of time at 500(deg)C was evaluated. Based on the results of these preliminary evaluations, two amplifiers were developed.

DelCastillo, Linda Y.; Johnson, Travis W.; Hatake, Toshiro; Mojarradi, Mohammad M.; Kolawa, Elizabeth A.

2006-01-01

252

SQUID linear amplifier circuit simulations  

SciTech Connect

This paper presents numerical simulations of a single stage of a linear SQUID amplifier. The amplifier stage is fabricated in thin film technology, and consists of two asymmetric SQUIDs placed in the push-pull configuration. It was found that the Q of the tank circuit formed by SQUID inductance and a parasitic strip-line capacitance must be reduced to unity to avoid hysteretic operation. A load line analysis has determined the amplifier operating point and SQUID inductance which yield optimum linearity.

Gershenson, M.; Hastings, R.; Schneider, R.; Sorensen, E.; Sweeny, M.

1983-09-01

253

Dynamical theory of polariton amplifiers.  

PubMed

We present the theory of the dynamics of the polariton amplifier in the region of small polariton densities. We give an analytical solution for the polariton condensate density matrix and show that the formation of a coherent quantum state is possible. Once the condensate is formed, the coherence becomes macroscopically long living. Polariton amplifier represents, therefore, an optical memory element, where the input weak coherent signal can be amplified and kept. PMID:14611482

Rubo, Yuri G; Laussy, F P; Malpuech, G; Kavokin, A; Bigenwald, P

2003-10-10

254

Experimental investigation on wideband intermodulation distortion compensation characteristics of 3.5GHz band 140-W class feed-forward power amplifier employing GaN HEMTs  

Microsoft Academic Search

This paper presents an experimental investigation on the wideband intermodulation distortion compensation characteristics of a 3.5-GHz feed-forward power amplifier for mobile base stations. The fabricated 3.5-GHz band 140-W class feed-forward power amplifier employing gallium nitride high electron mobility transistors (GaN HEMTs) achieves the intermodulation distortion compensation bandwidth of 160 MHz at the output power of 12.5 W and the adjacent

Yasunori Suzuki; Junya Ohkawara; Shoichi Narahashi

2010-01-01

255

Experimental investigation of 3-W class-AB cryogenically-cooled amplifier employing GaN HEMT for front end receivers of mobile base stations  

Microsoft Academic Search

This paper presents experimental results of a 2-GHz band gallium nitride high electron mobility transistor (GaN HEMT) amplifier cryogenically-cooled to 60K as a part of the cryogenic receiver front end (CRFE) for mobile base station receivers. At a temperature of 60K, the GaN HEMT amplifier attains the maximum power added efficiency of 62%, the saturation output power of 35dBm, the

Y. Suzuki; S. Narahashi; T. Nojima

2008-01-01

256

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

257

Reflex ring laser amplifier system  

SciTech Connect

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, M.A.

1985-10-22

258

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

259

The Microstrip SQUID Amplifier: Searching for the Axion  

NASA Astrophysics Data System (ADS)

The axion detector [1] at LLNL 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 the amplifier was a HEMT (High Electron Mobility Transistor) with a noise temperature TN of 1.7 K. Thus, the system noise temperature Ts was 3.2 K. In an attempt to achieve significantly lower noise temperatures, we fabricated amplifiers based on the dc SQUID [2] (Superconducting QUantum Interference Device). The theory [3] for SQUID amplifiers with a resonant input circuit predicts that an optimized device at sufficiently low temperatures should be quantum limited, that is, TN = hf/k at frequency f. To extend the operating frequency to the gigahertz range, we developed the Microstrip SQUID Amplifier (MSA) in which the input coil forms a microstrip with the SQUID washer [4, 5]. 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 [6] of an MSA in which the resistive shunts of the junctions were coupled to cooling fins to reduce hot electron effects [7]. At 0.62 GHz, we achieved a minimum noise temperature TN = 48+/-5mK for a bath temperature of 50 mK and at a frequency 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 Ts2, replacing the HEMT with a SQUID and cooling the cavity to 50 mK potentially reduces the scan time by three orders of magnitude.

Clarke, John

2009-12-01

260

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

261

Quantum-well-base heterojunction bipolar light-emitting transistor  

NASA Astrophysics Data System (ADS)

This letter reports the enhanced radiative recombination realized by incorporating InGaAs quantum wells in the base layer of light-emitting InGaP/GaAs heterojunction bipolar transistors (LETs) operating in the common-emitter configuration. Two 50 Å In1-xGaxAs (x=85%) quantum wells (QWs) acting, in effect, as electron capture centers (``traps'') are imbedded in the 300 Å GaAs base layer, thus improving (as a ``collector'' and recombination center) the light emission intensity compared to a similar LET structure without QWs in the base. Gigahertz operation of the QW LET with simultaneously amplified electrical output and an optical output with signal modulation is demonstrated.

Feng, M.; Holonyak, N.; Chan, R.

2004-03-01

262

Flexible organic transistor memory devices.  

PubMed

The flexible nonvolatile organic memory devices were developed on the plastic substrates based on the organic thin-film transistors embedding self-assembled gold nanoparticles (Au(NP)). The organic memory devices exhibited good programmable memory characteristics with respect to the program/erase operations, resulting in controllable and reliable threshold voltage shifts. Additionally, the endurance, data retention, and bending cyclic measurements confirmed that the flexible memory devices exhibited good electrical reliability as well as mechanical stability. The memory devices were composed of the solution-processed organic dielectric layers/metallic nanoparticles and the low-temperature processed organic transistors. Therefore, this approach could potentially be applied to advanced flexible/plastic electronic devices as well as integrated organic device circuits. PMID:20578683

Kim, Soo-Jin; Lee, Jang-Sik

2010-08-11

263

All-optical polariton transistor  

NASA Astrophysics Data System (ADS)

Although optical technology provides the best solution for the transmission of information, all-optical devices must satisfy several qualitative criteria to be used as logic elements. In particular, cascadability is difficult to obtain in optical systems, and it is assured only if the output of one stage is in the correct form to drive the input of the next stage. Exciton-polaritons, which are composite particles resulting from the strong coupling between excitons and photons, have recently demonstrated huge non-linearities and unique propagation properties. Here we show that polariton fluids moving in the plane of the microcavity can operate as input and output of an all-optical transistor, obtaining up to 19 times amplification and demonstrating the cascadability of the system. Moreover, the operation as an AND/OR gate is shown, validating the connectivity of multiple transistors in the microcavity plane and opening the way to the implementation of polariton integrated circuits.

Ballarini, D.; de Giorgi, M.; Cancellieri, E.; Houdré, R.; Giacobino, E.; Cingolani, R.; Bramati, A.; Gigli, G.; Sanvitto, D.

2013-04-01

264

A graphene-based hot electron transistor.  

PubMed

We experimentally demonstrate DC functionality of graphene-based hot electron transistors, which we call graphene base transistors (GBT). The fabrication scheme is potentially compatible with silicon technology and can be carried out at the wafer scale with standard silicon technology. The state of the GBTs can be switched by a potential applied to the transistor base, which is made of graphene. Transfer characteristics of the GBTs show ON/OFF current ratios exceeding 10(4). PMID:23488893

Vaziri, Sam; Lupina, Grzegorz; Henkel, Christoph; Smith, Anderson D; Ostling, Mikael; Dabrowski, Jarek; Lippert, Gunther; Mehr, Wolfgang; Lemme, Max C

2013-04-10

265

Pentacene thin film transistors and inverter circuits  

Microsoft Academic Search

Organic thin film transistors and simple electronic circuits have been fabricated using the fused-ring small-molecule aromatic hydrocarbon pentacene as the active material. Carrier field-effect mobilities greater than 0.2 cm2\\/V-s were obtained for thin film transistors fabricated on glass using low-temperature ion-beam deposited silicon dioxide as the gate dielectric and thermally evaporated pentacene as the active material. Using similar transistors, integrated

Hagen Klauk; Yen-Yi Lin; David J. Gundlach; Thomas N. Jackson

1997-01-01

266

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

267

Transverse Bragg resonance laser amplifier  

Microsoft Academic Search

We propose and analyze a new type of optical amplifier that is formed by addition of gain in the periodic cladding of a transverse Bragg resonance waveguide [Opt. Lett. 27, 936 (2002)]. Using the coupled-wave formalism, we calculate the mode profiles, the exponential gain constant, and, for comparison, the gain enhancement compared with those of conventional semiconductor optical amplifiers. In

Amnon Yariv; Yong Xu; Shayan Mookherjea

2003-01-01

268

Deflection amplifier for image dissectors  

NASA Technical Reports Server (NTRS)

Balanced symmetrical y-axis amplifier uses zener-diode level shifting to interface operational amplifiers to high voltage bipolar output stages. Nominal voltage transfer characteristic is 40 differential output volts per input volt; bandwidth, between -3-dB points, is approximately 8 kHz; loop gain is nominally 89 dB with closed loop gain of 26 dB.

Salomon, P. M.

1977-01-01

269

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

270

Ytterbium-doped fiber amplifiers  

Microsoft Academic Search

The ytterbium-doped fiber amplifier offers a number of attractive features, including a broad-gain bandwidth and a high efficiency, due in large part to its freedom from various competing processes seen in other rare-earth dopants. Here we discuss the main features that influence design and possible applications of ytterbium-doped fiber amplifiers

R. Paschotta; J. Nilsson; A. C. Tropper; D. C. Hanna

1997-01-01

271

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

272

Organic field-effect transistors  

Microsoft Academic Search

The paper reviews the recent year publications concerning organic field-effect transistors (OFETs). A lot of works have been\\u000a performed to help understanding the structural and electrical properties of materials used to construct OFETs. It has been\\u000a established that in partially ordered systems, the charge transport mechanism is thermally activated and field-assisted hopping\\u000a transport and the hopping transport between disorder-induced localized

M. J. Ma?achowski; J. ?mija

2010-01-01

273

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

274

Semi-classical modeling of nano-mechanical transistors  

NASA Astrophysics Data System (ADS)

The introduction of vibration-based Nano Electro-Mechanical Transistors (NEMT) opens a new horizon for mechanics in computer science. NEMT working principle is based on an electrical charge shuttle between two electrodes operated by a vibrating conductor body. Advantages of these novel devices would be very low power dissipation, limited influence of external electromagnetic disturbances, and improved thermal resistance. The paper introduces an analytical model for such a device, in which the matching of a mechanical resonator and an electric circuit is studied: the coupling is provided by capacitance effects, electrostatic force and the quantum tunneling. The approach is quasi-classical, describing the quantum phenomena through a non-linear conductance and using a continuous variable for the charges. Through suitably introduced simplifications, the model is reduced to a set of two differential equations in terms of pillar position and charge. These equations represent the simplest model still preserving the basic phenomenology of the investigated system. Numerical simulations show different possible motion regimes, both in the single- and multiple-module configurations, the latter able to reproduce the conventional transistor functionality. This opens the way to mechanical voltage-driven switches or amplifiers.

Scorrano, Alessandro; Carcaterra, Antonio

2013-08-01

275

All-Optical Transistor Action in Photonic Band Gap Materials  

NASA Astrophysics Data System (ADS)

We describe all-optical transistor action in photonic band gap materials doped with active atoms. In the presence of a photonic band gap (PBG) material, a coherent laser beam with the frequency slightly detuned from the resonant atomic transition frequency can drive a collection of two-level atoms to an almost totally inverted state, a phenomenon strictly forbidden in ordinary vacuum. By changing the laser field intensity in the neighborhood of a threshold value, it is possible to drive the atomic system through a transition from states in which the atoms populate preferentially the ground level to almost totally inverted states. In this process, the atomic system switches from a passive medium (highly absorptive) to a active medium (highly amplifying). The switching action in a PBG material is not associated with operating near a narrow cavity resonance with conventional trade-off between switching time and switching threshold intensity. Rather it is associated with an abrupt discontinuity in the engineered broad band electromagnetic density of states of the PBG material. We demonstrate all-optical transistor action in PBG materials by analyzing the absorption spectrum of a second probe laser beam and we show that the probe beam experience a substantial differential gain by slight intensity modulations in the control laser field.

Florescu, Marian; John, Sajeev

2003-02-01

276

Radiation effects on junction field-effect transistors (JFETS), MOSFETs, and bipolar transistors, as related to SSC circuit design.  

National Technical Information Service (NTIS)

Some results of radiation effects on selected junction field-effect transistors, MOS field-effect transistors, and bipolar junction transistors are presented. The evaluations include dc parameters, as well as capacitive variations and noise evaluations. T...

E. J. Kennedy G. T. Alley C. L. Britton P. L. Skubic B. Gray

1990-01-01

277

Fluid pressure amplifier and system  

NASA Technical Reports Server (NTRS)

A flueric beam-deflection amplifier and a method of controlling the same are described. Either a single or a series of cascaded fluid amplifier units are provided and each one of which may include the usual power nozzle, control nozzles, outlet passages and vent passages. All vent passages of each fluid amplifier unit lead to an enclosed vent outlet chamber which is connected to the ambient environment or to a return manifold through a variably restricted passage. To control the fluid amplifier unit, power and control stream pressures are first established, after which the restricted passage is reduced to regulate the input bias, the gain and the input impedance of the fluid amplifier unit.

Garner, H. D.; Hellbaum, R. F. (inventors)

1973-01-01

278

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

279

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

280

JANTX2N2369A transistor  

NASA Technical Reports Server (NTRS)

Report describes effects of power and temperature overstress on National Semiconductor and Raytheon transistors. Good junction quality was maintained. Gain losses predominated. Other failures are reported.

1980-01-01

281

A programmable 1.5 V CMOS class-AB operational amplifier with hybrid nested Miller compensation for 120 dB gain and 6 MHz UGF  

Microsoft Academic Search

Traditionally, CMOS operational amplifiers apply cascoding techniques to ensure an acceptable gain with a minimal number of gain stages. The use of cascode transistors, however, limits the lowest supply voltage of a CMOS op amp. Lowering the threshold voltage of the MOS process, a development already initiated by many VLSI processing facilities, does not lead to a lower minimum supply

Ruud G. H. Eschauzier; Ron Hogervorst; Johan H. Huijsing

1994-01-01

282

Low-noise wide-band amplifiers for stochastic beam cooling experiments  

SciTech Connect

Noise characteristics of the continuous-wave wide-band amplifier systems for stochastic beam cooling experiments are presented. Also, the noise performance, bandwidth capability and gain stability of components used in these amplifiers are summarized and compared in the 100 MHz to 40 GHz frequency range. This includes bipolar and field-effect transistors, parametric amplifier, Schottky diode mixer and maser. Measurements of the noise characteristics and scattering parameters of variety GaAs FETs as a function of ambient temperature are also given. Performance data and design information are presented on a broadband 150-500 MHz preamplifier having noise temperature of approximately 35/sup 0/K at ambient temperature of 20/sup 0/K. An analysis of preamplifier stability based on scattering parameters concept is included.

Leskovar, B.; Lo, C.C.

1982-09-05

283

Multigate transistors as the future of classical metal-oxide-semiconductor field-effect transistors.  

PubMed

For more than four decades, transistors have been shrinking exponentially in size, and therefore the number of transistors in a single microelectronic chip has been increasing exponentially. Such an increase in packing density was made possible by continually shrinking the metal-oxide-semiconductor field-effect transistor (MOSFET). In the current generation of transistors, the transistor dimensions have shrunk to such an extent that the electrical characteristics of the device can be markedly degraded, making it unlikely that the exponential decrease in transistor size can continue. Recently, however, a new generation of MOSFETs, called multigate transistors, has emerged, and this multigate geometry will allow the continuing enhancement of computer performance into the next decade. PMID:22094690

Ferain, Isabelle; Colinge, Cynthia A; Colinge, Jean-Pierre

2011-11-17

284

Fundamentals of Electronics. Volume 2. Power Supplies and Amplifiers.  

National Technical Information Service (NTIS)

Contents: Power transformers; Electron tube rectifier circuits; Filter circuits; Regulator circuits; Triode amplifiers; Tetrode and pentode amplifiers; Paraphase amplifier circuits; Audio power amplifier; Decibles, microphones, and speakers.

1965-01-01

285

Operational Transconductance Amplifier Based Two-Stage Differential Charge Amplifiers  

Microsoft Academic Search

\\u000a A novel approach to the design of high-performance operational-amplifier-based differential charge amplifiers is proposed.\\u000a It is based on a two-stage topology: The first stage performs a differential measurement to single ended signal conversion,\\u000a providing a common mode rejection that only depends on the matching between two resistors; the second stage filters the signal.\\u000a These novel topologies that are based on

Dinesh. B. Bhoyar; Bharati Y. Masram

2010-01-01

286

Cryogenic Low Noise Amplifier with GaAs JFETs  

NASA Astrophysics Data System (ADS)

A SONY n-type GaAs junction field effect transistor (JFET) can operate at deep cryogenic temperatures without exhibiting kink phenomena or hysteresis in its I-V characteristics. Further the GaAs JFET has small gate leakage currents(<4.6×10-19A) and a minute input capacitance (0.037 pF). Moreover, even though the gate terminal of a JFET is surrounded by high-impedance materials, the noise level does not increase and a low noise level of ~500 nV/Hz1/2 at 1 Hz with low power dissipation (<1 ?W) was achieved. We are currently developing operational amplifiers (Op-Amps) and digital modules for cryogenically cooled high-sensitivity photodetection systems. The GaAs Op-Amp with an open loop gain of 2000 at a power dissipation of 6.5 ?W has been developed.

Fujiwara, Mikio; Nagata, Hirohisa; Hibi, Yasunori; Matsuo, Hiroshi; Sasaki, Masahide

2009-12-01

287

SEMICONDUCTOR INTEGRATED CIRCUITS: A 4 W K-band GaAs MMIC power amplifier with 22 dB gain  

NASA Astrophysics Data System (ADS)

A 4 W K-band AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) monolithic microwave integrated circuit (MMIC) high power amplifier (PA) is reported. This amplifier is designed to fully match for a 50 ? input and output impedance based on the 0.15 ?m power PHEMT process. Under the condition of 5.6 V and 2.6 A DC bias, the amplifier has achieved a 22 dB small-signal gain, better than a 13 dB input return loss, and 36 dBm saturation power with 25% PAE from 19 to 22 GHz.

Zhengliang, Huang; Faxin, Yu; Yao, Zheng

2010-03-01

288

Logic gates with a single graphene transistor  

Microsoft Academic Search

The operation of four basic two-input logic gates fabricated with a single graphene transistor is demonstrated. Single-transistor operation is obtained in a circuit designed to exploit the charge neutrality point of graphene to perform Boolean logic. The type of logic function is selected by offset of the input digital signals. The merits and limitations of the fabricated gates are assessed

Roman Sordan; Floriano Traversi; Valeria Russo

2009-01-01

289

UHF power transistors and Lecher line oscillators  

NASA Astrophysics Data System (ADS)

The construction of a transistor oscillator for Lecher, line and radiation demonstrations is described. The difficulties caused by the replacement of valves by transistors in this apparatus are specified, and a method for determining the impedance of the Lecher line is presented.

Howes, R. W.

1980-01-01

290

Uninterruptible Transistor-Inverter Power Supply.  

National Technical Information Service (NTIS)

A standard line of transistor-inverter power supplies with an unprecedented 500kVA maximum output has been developed. The main features include the use of transistors in the inverter section, eliminating the need for a commutation circuit; incorporation o...

Y. Shikano T. Morikawa T. Nakamura H. Wataka T. Kaneko

1983-01-01

291

Polycrystalline Diamond Junction Field Effect Transistors (JFETS).  

National Technical Information Service (NTIS)

The overall objective of this work is to develop a diamond junction field effect transistor (JFET) technology. The JFET transistor design is an approach that takes advantage of diamonds large bandgap and utilizes this property to help overcome the lack of...

D. Moyer M. Landstrass

1990-01-01

292

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

293

Controlling Transistor Temperature During Burn-In  

NASA Technical Reports Server (NTRS)

Boiling refrigerant provides simple temperature control for newly manufactured power transistors. Heat-transfer liquid is Fluorinert FC-77 (or equivalent). Liquid boils at 100 degrees C, which is specified temperature at which transistor cases should be maintained during burn-in with this technique.

Scott, B. C.

1986-01-01

294

Radiation Hard Silicon Nanowire Field Effect Transistors  

Microsoft Academic Search

Silicon nanowire-based transistors were fabricated and tested for their radiation hardness by exposure to Co60 X-ray radiation at doses ranging from 50-250 kRad. Minor degradation of the transistor characteristics was observed at 250 kRad. Our results show the inherent radiation hardness of nanowire devices.

L. Tsakalakos; P. Losee; J. Balch; A. L. Bogorad; W. J. Taft; J. J. Likar; R. Herschitz

2008-01-01

295

CADAT field-effect-transistor simulator  

NASA Technical Reports Server (NTRS)

CADAT field-effect transistor simulator (FETSIM) analyzes dc and transient behavior of metal-oxide-semiconductor (MOS) circuits. Both N-MOS and P-MOS transistor configurations in either bulk of silicon-on-sapphire (SOS) technology and almost any combination of R/C elements are analyzed.

1981-01-01

296

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.

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

2009-01-01

297

All-optical transistor using a photonic-crystal cavity with an active Raman gain medium  

NASA Astrophysics Data System (ADS)

We propose a design of an all-optical transistor based on a one-dimensional photonic-crystal cavity doped with a four-level N-type active Raman gain medium. The calculated results show that in a photonic-crystal cavity of this kind transmission and reflection of the probe (Raman) beam are strongly dependent on the optical switching power. Transmission and reflection of the probe beam can be greatly amplified or attenuated. Therefore the optical switching field can serve as a gate field of the transistor to effectively control propagation of the weak probe field. It is shown that the group velocity of the probe pulse can be controlled in the range from subluminal (slow light) to superluminal (fast light).

Arkhipkin, V. G.; Myslivets, S. A.

2013-09-01

298

Magnetoamplification in a bipolar magnetic junction transistor.  

PubMed

We have demonstrated the first bipolar magnetic junction transistor using a dilute magnetic semiconductor. For an InMnAs p-n-p transistor magnetoamplification is observed at room temperature. The observed magnetoamplification is attributed to the magnetoresistance of the magnetic semiconductor InMnAs heterojunction. The magnetic field dependence of the transistor characteristics confirm that the magnetoamplification results from the junction magnetoresistance. To describe the experimentally observed transistor characteristics, we propose a modified Ebers-Moll model that includes a series magnetoresistance attributed to spin-selective conduction. The capability of magnetic field control of the amplification in an all-semiconductor transistor at room temperature potentially enables the creation of new computer logic architecture where the spin of the carriers is utilized. PMID:20867602

Rangaraju, N; Peters, J A; Wessels, B W

2010-09-10

299

Amplifier arrays for CMB polarization  

NASA Technical Reports Server (NTRS)

Cryogenic low noise amplifier technology has been successfully used in the study of the cosmic microwave background (CMB). MMIC (Monolithic Millimeter wave Integrated Circuit) technology makes the mass production of coherent detection receivers feasible.

Gaier, Todd; Lawrence, Charles R.; Seiffert, Michael D.; Wells, Mary M.; Kangaslahti, Pekka; Dawson, Douglas

2003-01-01

300

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

301

Techniques of microwave noise measurement on cooled transistors  

NASA Astrophysics Data System (ADS)

Cooled low-noise microwave field effect transistor (FET) amplifiers are widely used in radio telescopes, satellite earth stations, and radar systems to minimize noise added to the signal by the receiver. In designing these amplifiers, the noise parameters of the FETs must be known. It is hard to obtain these parameters, especially at cryogenic temperatures. A load having an electronically controlled reflection coefficient (RC) and noise temperature was built and used to measure the noise parameters of a GaAs FET at 12 K at frequencies in the 1.2-1.6 GHz range. The electronic load simplified the measurement of noise parameters at cryogenic temperatures because its RC was adjusted from outside the cooling apparatus, and the RCs were repeatable. A number of novel techniques for measuring noise and for estimating the noise parameters of a noise measurement receiver and of the device under test were developed. Singular value decomposition was used to improve and analyze noise parameter estimation by least squares fitting. The measurement errors due to frequency errors and non-zero noise power measurement bandwidth were analyzed. A new notation was introduced to simplify the analysis of noisy linear circuits and was used to develop cascading and de-embedding equations for noisy linear two-ports, and was also used to develop some of the new measurement techniques.

Valk, Eric C.

302

High current CMOS operational amplifier  

Microsoft Academic Search

This paper describes a low voltage CMOS operational amplifier, which is capable of driving heavy resistive and capacitive loads. Robust and power efficient compensation is achieved by using Miller compensation together with a high bandwidth stage. Measurements show that the amplifier achieves 5.7 MHz unity gain frequency and 61° phase margin when driving 1nF||1k? load, while drawing 2.4mA from 1.5V

Mikko Loikkanen; Juha Kostamovaara

2005-01-01

303

Inductive Single-Electron Transistor  

NASA Astrophysics Data System (ADS)

We demonstrate a sensitive method of charge detection based on radio-frequency readout of the Josephson inductance of a superconducting single-electron transistor. Charge sensitivity 1.4×10-4 e/?(Hz), limited by a preamplifier, is achieved in an operation mode which takes advantage of the nonlinearity of the Josephson potential. Owing to reactive readout, our setup has more than 2orders of magnitude lower dissipation than the existing method of radio-frequency electrometry. With an optimized sample, we expect uncoupled energy sensitivity below ? in the same experimental scheme.

Sillanpää, Mika A.; Roschier, Leif; Hakonen, Pertti J.

2004-08-01

304

Inductive single-electron transistor.  

PubMed

We demonstrate a sensitive method of charge detection based on radio-frequency readout of the Josephson inductance of a superconducting single-electron transistor. Charge sensitivity 1.4 x 10(-4) e/square root Hz, limited by a preamplifier, is achieved in an operation mode which takes advantage of the nonlinearity of the Josephson potential. Owing to reactive readout, our setup has more than 2 orders of magnitude lower dissipation than the existing method of radio-frequency electrometry. With an optimized sample, we expect uncoupled energy sensitivity below variant Planck's over h in the same experimental scheme. PMID:15323652

Sillanpää, Mika A; Roschier, Leif; Hakonen, Pertti J

2004-08-01

305

A 1.2 V Broadband Low Noise Fully Differential Amplifier in a 65 nm CMOS Technology  

Microsoft Academic Search

Abstract—A fully differential operational,amplifier in a 65nm CMOS technology is presented. It is designed for low power, low noise and,high bandwidth,applications. Transistors in a 65 nm CMOS technology,suffer from,increased,short channel,effects and noise contribution. Nevertheless, thermal noise density as low as 5nV\\/ p Hz and a 1 \\/f-corner Frequency,below 1MHz are achieved. The operational amplifier has a gain of 96dB consuming

Stefan Kaehlert; Tobias D. Werth; Ralf Wunderlich; Stefan Heinen

306

Millimeter-wave, cryogenically-coolable amplifiers using AlInAs\\/GaInAs\\/InP HEMTs  

Microsoft Academic Search

The cryogenic performance of AlInAs\\/GaInAs\\/InP 0.1- mu m high-electron-mobility transistors (HEMTs) is reported. Collapse-free DC operation is observed down to the ambient temperature of 18 K. The application of these devices to Q- and E-band low-noise, cryogenically coolable amplifiers is demonstrated. The measured noise temperature of 15 K (noise figure of 0.2 dB) for a multistage 40-45-GHz amplifier with 33

M. W. Pospieszalski; W. J. Lakatosh; R. Lai; K. L. Tan; D. C. Streit; P. H. Liu; R. M. Dia; J. Velebir

1993-01-01

307

AlGaN\\/GaN HFET power amplifier integrated with microstrip antenna for RF front-end applications  

Microsoft Academic Search

A high-efficiency and compact AlGaN\\/GaN heterojunction field-effect transistor (HFET) power amplifier integrated with a microstrip antenna at 7.25 GHz is presented for RF front-end circuit applications. A microstrip circular sector antenna is employed as both a radiator and frequency-dependent output load. Higher order harmonics from the HFET in nonlinear operation are reactively terminated because of the harmonic termination characteristic of

Younkyu Chung; Cynthia Y. Hang; Shujun Cai; Yongxi Qian; Cheng P. Wen; Kang L. Wang; Tatsuo Itoh

2003-01-01

308

Impedance optimization of linearizer to suppress intermodulation distortion in 2.45GHz SiGe WLAN power amplifier  

Microsoft Academic Search

An RF power amplifier (PA) for IEEE 802.11g WLAN terminals is implemented with 33 GHz-fT, 0.8-mum-SiGe bipolar technology. This paper demonstrates a linearizer consisting of a varactor diode and a base-emitter junction diode of a bias transistor. Intermodulation distortion (IMD) is suppressed by optimized impedance of the linearizer. The reactance of the varactor diode is minimized at low output power

Ji Hoon Kim; Ki Young Kim; Seung Hwan Won; Jae Jin Lee; Yun Hwi Park; Yul Kyo Jung; Seok Tae Kim; Chul Soon Park

2006-01-01

309

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

310

Voltage regulator for battery power source. [using a bipolar transistor  

NASA Technical Reports Server (NTRS)

A bipolar transistor in series with the battery as the control element also in series with a zener diode and a resistor is used to maintain a predetermined voltage until the battery voltage decays to very nearly the predetermined voltage. A field effect transistor between the base of the bipolar transistor and a junction between the zener diode and resistor regulates base current of the bipolar transistor, thereby regulating the conductivity of the bipolar transistor for control of the output voltage.

Black, J. M. (inventor)

1979-01-01

311

High-performance vertical organic transistors.  

PubMed

Vertical organic thin-film transistors (VOTFTs) are promising devices to overcome the transconductance and cut-off frequency restrictions of horizontal organic thin-film transistors. The basic physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self-assembly processes which impedes a future large-area production. In this contribution, high-performance vertical organic transistors comprising pentacene for p-type operation and C60 for n-type operation are presented. The static current-voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self-assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high-performance applications of organic transistors. PMID:23637074

Kleemann, Hans; Günther, Alrun A; Leo, Karl; Lüssem, Björn

2013-11-11

312

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

313

Reflex ring laser amplifier system  

DOEpatents

The invention is a method and apparatus for providing a reflex ring laser system for amplifying an input laser pulse. The invention is particularly useful in laser fusion experiments where efficient production of high-energy and high power laser pulses is required. The invention comprises a large aperture laser amplifier in an unstable ring resonator which includes a combination spatial filter and beam expander having a magnification greater than unity. An input pulse is injected into the resonator, e.g., through an aperture in an input mirror. The injected pulse passes through the amplifier and spatial filter/expander components on each pass around the ring. The unstable resonator is designed to permit only a predetermined number of passes before the amplified pulse exits the resonator. On the first pass through the amplifier, the beam fills only a small central region of the gain medium. On each successive pass, the beam has been expanded to fill the next concentric non-overlapping region of the gain medium.

Summers, M.A.

1983-08-31

314

Inverting amplifier genetic circuit performance.  

PubMed

A synthetic genetic circuit has been designed whose topology and function echo those of an electronic inverting amplifier. Several variants of this circuit have been built in our laboratory. This paper reports on the testing of one of these variants and contributes to the field both in terms of evaluating the specific amplifier performance and in terms of providing a methodology for performance evaluation of analog genetic circuits. An input source was created and partially calibrated. It was then used to test the circuit through both fluorometer measurements and flow cytometry. In the discussion, consideration is given to cellular loading by the synthetic circuits and the resulting impact on circuit performance. Models developed earlier are compared with the experimental results. The circuit does indeed perform as an inverting amplifier. PMID:17947009

Nagaraj, S; Davies, S W

2006-01-01

315

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

316

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

317

Laser system using regenerative amplifier  

DOEpatents

High energy laser system is disclosed using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output. 10 figs.

Emmett, J.L.

1980-03-04

318

Quantum optical state comparison amplifier.  

PubMed

It is a fundamental principle of quantum theory that an unknown state cannot be copied or, as a consequence, an unknown optical signal cannot be amplified deterministically and perfectly. Here we describe a protocol that provides nondeterministic quantum optical amplification in the coherent state basis with high gain and high fidelity and which does not use quantum resources. The scheme is based on two mature quantum optical technologies: coherent state comparison and photon subtraction. The method compares favorably with all previous nondeterministic amplifiers in terms of fidelity and success probability. PMID:24313486

Eleftheriadou, Electra; Barnett, Stephen M; Jeffers, John

2013-11-22

319

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

320

High Performance Vertical Organic Field Effect Transistors.  

National Technical Information Service (NTIS)

This is a productive research project (12 papers in three years) aiming to understand the potential of conjugated polymer in a wide range of organic electronic devices - vertical transistors,solar cells and photodetectors, memory devices, as well as graph...

Y. Yang

2010-01-01

321

JAN transistor and diode characterization test program  

NASA Technical Reports Server (NTRS)

A statistical summary of electrical characterization was performed on JAN diodes and transistors. Parameters are presented with test conditions, mean, standard deviation, lowest reading, 10% point, 90% point and highest reading.

Takeda, H.

1977-01-01

322

Suspended Carbon Nanotube Field Effect Transistor.  

National Technical Information Service (NTIS)

The invention provides a carbon nanotube field effect transistor including a nanotube having a length suspended between source and drain electrodes. A gate dielectric material coaxially coats the suspended nanotube length and at least a portion of the sou...

H. Peng J. A. Golovchenko

2005-01-01

323

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

324

A CMOS class-A 65nm power amplifier for 60 GHz applications  

Microsoft Academic Search

A millimeter-wave power amplifier (PA) implemented in a 65 nm CMOS process with 8-metal layers and transistor fT\\/fMAX of 160\\/200 GHz is reported. The PA operates from a 1.2 V supply voltage. A power gain of 13.4 dB, an output P1dB of 12.2 dBm with 7.6 % PAE and a saturated output power of 13.8 dBm at 58 GHz are

T. Quemerais; L. Moquillon; S. Pruvost; J.-M. Fournier; P. Benech; N. Corrao

2010-01-01

325

Flicker Noise in Bilayer Graphene Transistors  

Microsoft Academic Search

We present results of the experimental investigation of the low-frequency noise in bilayer graphene transistors. The back-gated devices were fabricated using the electron beam lithography and evaporation. The charge neutrality point for the transistors was around +10 V. The noise spectra at frequencies f > 10-100 Hz were of the 1\\/f type with the spectral density on the order of

Qinghui Shao; Guanxiong Liu; Desalegne Teweldebrhan; Alexander A. Balandin; S. Roumyantesv; Michael S. Shur; Dong Yan

2009-01-01

326

Gold nanoparticle-pentacene memory transistors  

Microsoft Academic Search

We demonstrate an organic memory-transistor device based on a pentacene-gold nanoparticles active layer. Gold (Au) nanoparticles are immobilized on the gate dielectric (silicon dioxide) of a pentacene transistor by an amino-terminated self-assembled monolayer. Under the application of writing and erasing pulses on the gate, large threshold voltage shift (22 V) and on\\/off drain current ratio of ~3×104 are obtained. The

Christophe Novembre; David Guérin; Kamal Lmimouni; Christian Gamrat; Dominique Vuillaume

2008-01-01

327

Integrating transistors on high-ohmic silicon  

Microsoft Academic Search

This paper presents a compatible technology for integrating both radiation detectors and transistors on the same high-ohmic silicon substrate. Using this technology, chips have been fabricated containing a number of test transistors (MOSFETs) with different geometries. Measurements on the devices showed a threshold voltage between 0 and -3 V, and a transconductance between 25 muA\\/V and 1.25 mA\\/V for aspect

S. E. Wouters; S. A. Audet; M. H. Kim; E. M. Schooneveld

1990-01-01

328

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

329

Thermal Design of Multifinger Bipolar Transistors  

Microsoft Academic Search

In this paper, design guidelines are provided to improve the thermal stability of three- and four-finger bipolar transistors. Experiments and simulations are first performed on silicon-on-glass (SOG) three-finger bipolar junction transistors (BJTs) with self-heating and mutual thermal resistances varying in a large range of values, depending on the silicon area, presence of heat spreaders, isolation, and distance between fingers. To

Luigi La Spina; Vincenzo d'Alessandro; Salvatore Russo; Lis K. Nanver

2010-01-01

330

Refined Transistor Model For Simulation Of SEU  

NASA Technical Reports Server (NTRS)

Equivalent base resistance added. Theoretical study develops equations for parameters of Gummel-Poon model of bipolar junction transistor: includes saturation current, amplification factors, charging times, knee currents, capacitances, and resistances. Portion of study concerned with base region goes beyond Gummel-Poon analysis to provide more complete understanding of transistor behavior. Extended theory useful in simulation of single-event upset (SEU) caused in logic circuits by cosmic rays or other ionizing radiation.

Zoutendyk, John A.; Benumof, Reuben

1988-01-01

331

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

332

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

333

Pressure sensitive organic field effect transistor  

NASA Astrophysics Data System (ADS)

Thin films of organic semiconductor copper phthalocyanine (CuPc) and Al were deposited in sequence by vacuum evaporation on a glass substrate with Ag source and drain electrodes. The effect of pressure on the properties of the fabricated field effect transistor (FET) with metal (aluminum) - semiconductor (copper phthalocyanine) Schottky junction was investigated. It was observed that the drain-source resistance of this organic field effect transistor (OFET) decreased with pressure.

Karimov, Kh. S.; Saleem, M.; Mahroof-Tahir, M.; Khan, T. A.; Khan, Adam

2010-11-01

334

Shaping Transistor Leads for Better Solder Joints  

NASA Technical Reports Server (NTRS)

Special lead-forming tool puts step in leads of microwave power transistors without damaging braze joints that fasten leads to package. Stepped leads are soldered to circuit boards more reliably than straight leads, and stress on brazes is relieved. Lead-forming hand-tool has two parts: a forming die and an actuator. Spring-loaded saddle is adjusted so that when transistor package is placed on it, leads rest on forming rails.

Mandel, H.; Dillon, J. D.

1982-01-01

335

CONTUNT: Thin SOI control tunneling transistor  

NASA Astrophysics Data System (ADS)

A tunneling transistor (CONTUNT) compatible with ultra-thin SOI technology is presented. The gate controls the long depletion region of the drain p-n + junction when the longitudinal component of the electric field becomes large enough to enable interband tunneling. The drain tunnel current strongly depends on the gate voltage. Our analytical model shows that the transistor transconductance and frequency of operation can reach about 1 (A/V)/mm and 1 THz, respectively.

Dobrovolsky, V.; Rossokhaty, V.; Cristoloveanu, S.

2006-05-01

336

Simulation study of SOI four gate transistor  

Microsoft Academic Search

The structure of silicon-on-insulator (SOI) four-gate transistor (G4-FET) and its different parameters for different biasing conditions are studied. A G4-FET simulation model was developed by Silvaco\\/Atlas 3-D simulator which incorporates non-ideal effects like concentration dependent mobility, Shockley-Read-Hall recombination, Auger recombination, bandgap narrowing effect. This model can be useful in measuring parameters dependency of a SOI four gate transistor.

Bishwajit Debnath; M. Sariful Islam; Samantha Lubaba Noor; Muhsiul Hassan; A. F. M. Saniul Haq; M. Ziaur Rahman Khan

2012-01-01

337

Development of High Sensitive Senor System by Use of Immobilized Enzyme and Its Analytical Application: Preparation of Enzyme FET (Field Effect Transistor) Electrode Responding to Redox Potential and Its Characteristics,  

National Technical Information Service (NTIS)

In order to amplify the applicability of chemical sensor using field effect transistor (FET), oxidation/reduction FET electrode (Redox-FET) and enzyme FET electrode which combined specificities of Redox-FET and enzyme were made and the following results w...

T. Wasa T. Yao M. Ueno

1988-01-01

338

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

339

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.

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

2010-01-01

340

Tunnel diode amplifier SGEMP response  

Microsoft Academic Search

The paper discusses the SGEMP response of an X-band tunnel diode amplifier design in a flash X-ray environment due to particular cavity design characteristics. SGEMP currents are not limited, and thus can result in tunnel diode damage because of its low burnout energy threshold. Eight diodes were damaged due to SGEMP and their damage threshold energies were calculated, using tunnel

J. L. Andrews; D. H. Swant; B. L. Beers

1979-01-01

341

Tunnel Diode Amplifier SGEMP Response  

Microsoft Academic Search

An X-band tunnel diode amplifier (TDA) has been studied for SGEMP response. This study has involved analytical modeling and predictions, tunnel diode electrical pulsing to develop damage statistics, and experimental measurements in an 800 kvp flash X-ray environment. In contrast to photocurrent limited TREE response, significant SGEMP replacement currents can flow through the tunnel diode. This response is associated with

J. L. Andrews; D. H. Swant; B. L. Beers

1979-01-01

342

Graphene terahertz sources and amplifiers  

Microsoft Academic Search

Plasmons in population inverted graphene can experience extremely large gain through the process of stimulated emission at terahertz frequencies. The large gain values and the small plasmon wavelengths can lead to compact terahertz plasmon lasers and amplifiers that are only a few microns in size. We present optical and terahertz spectroscopy results for carrier relaxation and recombination dynamics in graphene

F. Rana; P. A. George; J. H. Strait; J. Dawlaty

2008-01-01

343

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

344

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.

2014-01-01

345

Cryogenic amplifier for shot noise measurement at 20 mK  

NASA Astrophysics Data System (ADS)

We developed a shot noise measurement system for mesoscopic conductors (typical resistance h/2e2 = 12.9 k?) at very low temperature (~20 mK). To realize required high-resolution measurement, we made a high-electron-mobility-transistor (HEMT)-based cryogenic amplifier working at a target frequency range (~2.5 MHz), whose gain flatness and input voltage noise were carefully tuned. We can suppress the 1/f noise of the amplifier by using two HEMTs in parallel. The performance of the noise measurement system at 20 mK was demonstrated for a quantum point contact with high experimental accuracy below 10-29 A2/Hz.

Arakawa, Tomonori; Nishihara, Yoshitaka; Maeda, Masahiro; Norimoto, Shota; Kobayashi, Kensuke

2013-10-01

346

The Bipolar Field-Effect Transistor: VII. The Unipolar Current Mode for Analog-RF Operation (Two-MOS-Gates on Pure-Base)  

NASA Astrophysics Data System (ADS)

This paper reports the DC steady-state current-voltage and conductance-voltage characteristics of a Bipolar Field-Effect Transistor (BiFET) under the unipolar (electron) current mode of operation, with bipolar (electron and hole) charge distributions considered. The model BiFET example presented has two MOS-gates on the two surfaces of a thin pure silicon base layer with electron and hole contacts on both edges of the thin base. The hole contacts on both edges of the thin pure base layer are grounded to give zero hole current. This 1-transistor analog-RF Basic Building Block nMOS amplifier circuit, operated in the unipolar current mode, complements the 1-transistor digital Basic Build Block CMOS voltage inverter circuit, operated in the bipolar-current mode just presented by us.

Binbin, Jie; Chih-Tang, Sah

2009-03-01

347

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

348

Highly stable biased amplifier and stretcher system  

NASA Technical Reports Server (NTRS)

Amplifier and stretcher system, which minimizes thermal effects and compensates for repetition-rate effects, maintains resolution levels in spectrum analysis. An additional inverting amplifier is used in the system to provide a noiseless charge restorer.

Roddick, R. G.

1970-01-01

349

Magnetic Bubble Traveling-Wave Amplifier.  

National Technical Information Service (NTIS)

A theoretical investigation is presented that exploits the magnetic bubble phenomena for producing a new type of traveling-wave amplifier (TWA) called the Magnetic Bubble Traveling-Wave Amplifier (MBTWA). The theoretical analysis follows the method used b...

L. J. Jasper

1979-01-01

350

Unconditionally Stable Microwave Si-IMPATT Amplifiers.  

National Technical Information Service (NTIS)

The purpose of this investigation has been the development of an improved understanding of the design and analysis of microwave reflection amplifiers employing the negative resistance property of the IMPATT devices. Unconditionally stable amplifier circui...

M. M. Seddik

1986-01-01

351

Power amplifier linearization using cubic spline interpolation  

Microsoft Academic Search

An adaptive RF power amplifier linearization technique is presented. The demodulated amplifier output is compared with the baseband input signal to estimate the amplifier's AM-AM and AM-PM characteristics, using cubic spline interpolation. The input signal is predistorted using these estimated characteristics to compensate for the amplifier's nonlinearity. The proposed technique has nearly 14 dB better suppression of the intermodulation products

Anit Lohtia; Paul A. Goud; Colin G. Englefield

1993-01-01

352

Light amplification in polymer field effect transistor structures  

NASA Astrophysics Data System (ADS)

The amplified spontaneous emission (ASE) of optically pumped films of poly(2-(2',5'-bis(octyloxy)benzene)-1,4-phenylenevinylene (BOP-PPV) was studied in structures comprising a gate electrode, a thin film of gate insulator material (SiO2) and the polymer film as luminescent semiconducting layer (i.e. a field effect transistor without the source and drain electrodes). The influences of different gate electrodes on the threshold and the wavelength of the amplified emission were measured for variable thickness of the gate insulator. An exponential increase in ASE threshold (It) with decreasing separation between electrode and polymer layer was observed. In structures with 200 nm SiO2 gate insulator, It=300 kW/cm2 with an n-Si gate electrode and 200 kW/cm2 with Au electrode (100 nm thick). Compared to the same polymer film on pure SiO2 (It=2 kW/cm2), this increase results from waveguide losses in the nearby gate electrode. With an indium-tin-oxide (ITO) gate electrode (140 nm thick) on glass, again with a 200 nm SiO2 gate insulator, It=30 kW/cm2. The ITO electrode acts as a second waveguide, and the light is distributed into two modes. The observed wavelength shift and the increasing It with decreasing SiO2 thickness result from this mode structure. When the thickness of the ITO electrode is less than 60 nm, the mode traveling mainly in the ITO is cutoff, and a single waveguide structure is formed with an associated reduction in It. For an ITO thickness of 12 nm, It=4 kW/cm2, only two times bigger than that observed in a pure BOP-PPV film on fused silica.

Pauchard, Marc; Swensen, James; Moses, Daniel; Heeger, Alan J.; Perzon, Erik; Andersson, Mats R.

2003-09-01

353

Doped organic transistors operating in the inversion and depletion regime  

NASA Astrophysics Data System (ADS)

The inversion field-effect transistor is the basic device of modern microelectronics and is nowadays used more than a billion times on every state-of-the-art computer chip. In the future, this rigid technology will be complemented by flexible electronics produced at extremely low cost. Organic field-effect transistors have the potential to be the basic device for flexible electronics, but still need much improvement. In particular, despite more than 20 years of research, organic inversion mode transistors have not been reported so far. Here we discuss the first realization of organic inversion transistors and the optimization of organic depletion transistors by our organic doping technology. We show that the transistor parameters—in particular, the threshold voltage and the ON/OFF ratio—can be controlled by the doping concentration and the thickness of the transistor channel. Injection of minority carriers into the doped transistor channel is achieved by doped contacts, which allows forming an inversion layer.

Lüssem, Björn; Tietze, Max L.; Kleemann, Hans; Hoßbach, Christoph; Bartha, Johann W.; Zakhidov, Alexander; Leo, Karl

2013-11-01

354

Ion Implanted High Microwave Power Indium Phosphide Transistors.  

National Technical Information Service (NTIS)

Indium phosphide (InP) metal-insulator-semiconductor field-effect transistors (MISFETs) have demonstrated substantially higher output power density at microwave frequencies compared to gallium arsenide metal-semiconductor field-effect transistors (MESFETs...

R. Nguyen

1989-01-01

355

Design of hysteresis circuits using differential amplifiers  

NASA Technical Reports Server (NTRS)

Design equations for hysteresis circuit are based on the following assumptions: amplifier input impedance is larger than source impedance; amplifier output impedance is less than load impedance; and amplifier switches state when differential input voltage is approximately zero. Circuits are designed to any given specifications.

Cooke, W. A.

1971-01-01

356

Quasi-Optical Constrained Lens Amplifiers.  

National Technical Information Service (NTIS)

A major goal in the field of quasi-optics is to increase the power available from solid state sources by combining the power of individual devices in free space, as demonstrated with grid oscillators and grid amplifiers. Grid amplifiers and most amplifier...

J. S. Schoenberg

1995-01-01

357

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

358

Modeling erbium-doped fiber amplifiers  

Microsoft Academic Search

Erbium-doped fiber amplifiers are modeled using the propagation and rate equations of a homogeneous two-level laser medium. Numerical methods are used to analyze the effects of optical modes and erbium confinement on amplifier performance, and to calculate both the gain and amplified spontaneous emission (ASE) spectra. Fibers with confined erbium doping are completely characterized from easily measured parameters: the ratio

C. Randy Giles; Emmanuel Desurvire

1991-01-01

359

The operational amplifier in linear active networks  

Microsoft Academic Search

In this article the two-port characteristics, the gain stability, and the sensitivity of the nonideal operational amplifier are presented. A unified approach is taken to cover both the inverting and the noninverting modes of amplifier operation. Some of the sensitivity aspects pertaining to network synthesis using operational amplifiers are also discussed.

G. S. Moschytz

1970-01-01

360

Erbium-doped fiber amplifiers: linear approximations  

Microsoft Academic Search

In this paper, we show that there is a simple linear model for an erbium-doped fiber amplifier. Specifically, we show that the amplifier gain, raised to a wavelength-dependent power, is strongly linear with respect to the amplifier-induced increase in signal power

I. M. I. Habbab; A. A. M. Saleh; P. K. Runge

1995-01-01

361

Nonlinear predistortion for dynamic power amplifiers linearization  

Microsoft Academic Search

Signal predistortion is suitable for linearizing amplifier nonlinearity in high speed wireless applications. Volterra series provide an input-output relationship for nonlinear system with memory. The paper presents a new digital predistortion approach for the power amplifier linearization when we use the Volterra series for dynamic nonlinear modeling of the power amplifier comportment. The major advantage of the method is that

Ovidiu Leulescu; Teodor Petrescu

2005-01-01

362

Two stage double layer microstrip spatial amplifiers  

Microsoft Academic Search

Several two stage spatial amplifiers are presented. The amplifiers were constructed on double layer back to back microstrip circuits with a shared ground plane. The ground plane provides an effective isolation between the receiving antenna array and the transmitting antenna array. Furthermore, it serves as a heat sink in high-power amplifier design. The coupling between the two stages is accomplished

Toni Ivanov; Arnir Mortazawi

1995-01-01

363

Amplifier pumping optimization (in French)  

NASA Astrophysics Data System (ADS)

Slabs in NIF/LMJ large-aperture amplifiers are set at Brewster angle between two lamp arrays. A 2D+ ray-trace code is used to predict pump and gain coefficients profiles in the aperture. Code predictions, in good agreement with experimental results, show the high decay rate due to amplification of spontaneous emission leads to a strong depletion of the stored energy on the edges of the slabs. To compensate for this roll-off, shaped reflectors were calculated at CEL-V, using a dedicated routine added to the ray-trace code. They were fabricated and tested on the modified beamlet amplifier at LLNL. Numerical and experimental results agree to show that it is possible to redirect light using shaped reflectors, and that directing the pump radiation towards the edges of the aperture leads to a more uniform gain.

Le Touze, Geoffroy; Cabourdin, Olivier; Guenet, Mireille; Mengue, J. F.; Jancaitis, Kenneth S.; Rotter, Mark D.

1997-12-01

364

Operational Amplifiers Animation/Presentation  

NSDL National Science Digital Library

This presentation, by Arizona State University, addresses operational amplifiers; their structure, construction and applications of the technology. The site is broken down into ten sections; these are: an introduction, terminal connections, op-amp internals, ideal op-amp equations, circuit analysis example, voltage follower, inverting configuration, non-inverting configuration, differentiators, and integrators. Overall, the site is flashy, but still informative presentation of this technology.

Holbert, Keith E.

2010-03-18

365

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

366

338-GHz Semiconductor Amplifier Module  

NASA Technical Reports Server (NTRS)

Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers.

Samoska, Lorene A.; Gaier, Todd C.; Soria, Mary M.; Fung, King Man; Rasisic, Vesna; Deal, William; Leong, Kevin; Mei, Xiao Bing; Yoshida, Wayne; Liu, Po-Hsin; Uyeda, Jansen; Lai, Richard

2010-01-01

367

Sub-100 nm channel length graphene transistors  

PubMed Central

Here we report high performance sub-100 nm channel length grapheme transistors fabricated using a self-aligned approach. The graphene transistors are fabricated using a highly-doped GaN nanowire as the local gate, with the source and drain electrodes defined through a self-aligned process and the channel length defined by the nanowire size. This fabrication approach allows the preservation of the high carrier mobility in graphene, and ensures nearly perfect alignment between source, drain, and gate electrodes. It therefore affords transistor performance not previously possible. Graphene transistors with 45–100 nm channel lengths have been fabricated with the scaled transconductance exceeding 2 mS/µm, comparable to the best performed high electron mobility transistors with similar channel lengths. Analysis of and the device characteristics gives a transit time of 120–220 fs and the projected intrinsic cutoff transit frequency (fT) reaching 700–1400 GHz. This study demonstrates the exciting potential of graphene based electronics in terahertz electronics.

Liao, Lei; Bai, Jingwei; Cheng, Rui; Lin, Yungchen; Jiang, Shan; Qu, Yongquan; Huang, Yu; Duan, Xiangfeng

2010-01-01

368

Sub-100 nm channel length graphene transistors.  

PubMed

Here we report high-performance sub-100 nm channel length graphene transistors fabricated using a self-aligned approach. The graphene transistors are fabricated using a highly doped GaN nanowire as the local gate with the source and drain electrodes defined through a self-aligned process and the channel length defined by the nanowire size. This fabrication approach allows the preservation of the high carrier mobility in graphene and ensures nearly perfect alignment between source, drain, and gate electrodes. It therefore affords transistor performance not previously possible. Graphene transistors with 45-100 nm channel lengths have been fabricated with the scaled transconductance exceeding 2 mS/?m, comparable to the best performed high electron mobility transistors with similar channel lengths. Analysis of and the device characteristics gives a transit time of 120-220 fs and the projected intrinsic cutoff frequency (f(T)) reaching 700-1400 GHz. This study demonstrates the exciting potential of graphene based electronics in terahertz electronics. PMID:20815334

Liao, Lei; Bai, Jingwei; Cheng, Rui; Lin, Yung-Chen; Jiang, Shan; Qu, Yongquan; Huang, Yu; Duan, Xiangfeng

2010-10-13

369

Theory and application of dual-transistor charge separation analysis  

Microsoft Academic Search

The authors describe a dual-transistor charge separation method to evaluate the radiation response of MOS transistors. This method requires that n- and p-channel transistors with identically processed oxides be irradiated under identical conditions at the same oxide electric fields. Combining features of single-transistor midgap and mobility methods, the authors show how one may determine threshold voltage shifts due to oxide-trapped

D. M. Fleetwood; J. R. Schwank; P. S. Winokur; F. W. Sexton; M. R. Shaneyfelt

1989-01-01

370

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

371

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

1994-01-01

372

Advances in organic transistor-based biosensors: from organic electrochemical transistors to electrolyte-gated organic field-effect transistors.  

PubMed

Organic electronics have, over the past two decades, developed into an exciting area of research and technology to replace classic inorganic semiconductors. Organic photovoltaics, light-emitting diodes, and thin-film transistors are already well developed and are currently being commercialized for a variety of applications. More recently, organic transistors have found new applications in the field of biosensors. The progress made in this direction is the topic of this review. Various configurations are presented, with their detection principle, and illustrated by examples from the literature. PMID:21910013

Kergoat, Loïg; Piro, Benoît; Berggren, Magnus; Horowitz, Gilles; Pham, Minh-Chau

2012-02-01

373

Algorithms for automatic transistor sizing in CMOS digital circuits  

Microsoft Academic Search

This paper describes the algorithms for automatic transistor sizing (determination of device width and length) of CMOS digital circuits. In CMOS circuits, since power dissipation is small and not a limiting factor, the sizing algorithm is geared toward minimizing area. The program XTRAS (Xerox TRAnsistor Sizing Program) which determines transistor sizes as well as calculates path delays is described. Equations

William H. Kao; Nader Fathi; Chia-Hao Lee

1985-01-01

374

Sleep Transistor Sizing for Leakage Power Minimization Considering Temporal Correlation  

Microsoft Academic Search

Power gating is one of the most effective ways to reduce leakage power. In this paper, we introduce a new relationship among maximum instantaneous current, IR-drops and sleep transistor networks from a temporal viewpoint. Based on this relationship, we propose an algorithm to reduce the total sizes of sleep transistors in distributed sleep transistor network designs with the consideration of

De-Shiuan Chiou; Yu-Ting Chen; Da-Cheng Juan; Shih-Chieh Chang

2010-01-01

375

Sleep Transistor Sizing for Leakage Power Minimization Considering Charge Balancing  

Microsoft Academic Search

One of the effective techniques to reduce leakage power is power gating. Previously, a distributed sleep transistor network was proposed to reduce the sleep transistor area for power gating by connecting all the virtual ground lines together to minimize the maximum instantaneous current flowing through sleep transistors. In this paper, we propose a new methodology for determining the sizes of

De-Shiuan Chiou; Shih-Hsin Chen; Shih-Chieh Chang

2009-01-01

376

Coarse-Grain MTCMOS Sleep Transistor Sizing Using Delay Budgeting  

Microsoft Academic Search

Power gating is one of the most effective techniques in reducing the standby leakage current of VLSI circuits. In this paper we introduce a new approach for sleep transistor sizing which minimizes the total sleep transistor width for a coarse-grain multi-threshold CMOS circuit assuming a given standard cell and sleep transistor placement. First, the circuit is decomposed into a set

Ehsan Pakbaznia; Massoud Pedram

2008-01-01

377

Coarse-grain MTCMOS sleep transistor sizing using delay budgeting  

Microsoft Academic Search

Power gating is one of the most effective techniques in reducing the standby leakage current of VLSI circuits. In this paper we introduce a new approach for sleep transistor sizing which minimizes the total sleep transistor width for a coarse-grain multi-threshold CMOS circuit assuming a given standard cell and sleep transistor placement. First, the circuit is decomposed into a set

Ehsan Pakbaznia; Massoud Pedram

2008-01-01

378

Discrete transistor measuring and matching using a solid core oven  

NASA Astrophysics Data System (ADS)

This paper presents transistor measurements done at a constant temperature. The aim in this research was to develop a reliable and repeatable method for measuring and searching transistor pairs with similar parameters, as in certain applications it is advantageous to use transistors from the same production batch due to the significant variability in batches from different manufacturers. Transistor manufacturing methods are well established, but due to the large variability in tolerance, not even transistors from the same manufacturing batch have identical properties. Transistors' electrical properties are also strongly temperature-dependent. Therefore, when measuring transistor properties, the temperature must be kept constant. For the measurement process, a solid-core oven providing stable temperature was implemented. In the oven, the base-to-emitter voltage (VBE) and DC-current gain (?) of 32 transistors could be measured simultaneously. The oven's temperature was controlled with a programmable thermostat, which allowed accurate constant temperature operation. The oven is formed by a large metal block with an individual chamber for each transistor to be measured. Isolation of individual transistors and the highly thermally conductive metal core structure prevent thermal coupling between transistors. The oven enables repeatable measurements, and thus measurements between different batches are comparable. In this research study, the properties of over 5000 transistors were measured and the variance of the aforementioned properties was analyzed.

Inkinen, M.; Mäkelä, K.; Vuorela, T.; Palovuori, K.

2013-03-01

379

Microwave multiple-state resonant tunneling bipolar transistors  

Microsoft Academic Search

Fabrication and microwave performance of a multiple-state resonant-tunneling bipolar transistor (RTBT) are presented. This transistor exhibits a maximum DC current gain of 60 at room temperature and a cutoff frequency of 24 GHz. Frequency multiplication by a factor of five has been demonstrated with a single transistor

L. M. Lunardi; S. Sen; F. Capasso; P. R. Smith; D. L. Sivco; A. Y. Cho

1989-01-01

380

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

381

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

382

NIF/LMJ prototype amplifier mechanical design  

SciTech Connect

Amplifier prototypes for the National Ignition Facility and the Laser Megajoule will be tested at Lawrence Livermore National Laboratory. The prototype amplifier, which is an ensemble of modules from LLNL and Centre d`Etudes de Limeil-Valenton, is cassette-based with bottom access for maintenance. A sealed maintenance transfer vehicle which moves optical cassettes between the amplifier and the assembly cleanroom, and a vacuum gripper which holds laser slabs during cassette assembly will also be tested. The prototype amplifier will be used to verify amplifier optical performance, thermal recovery time, and cleanliness of mechanical operations.

Horvath, J.

1996-10-01

383

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

384

Radiofrequency Nanoelectrolytic Debye-Layer Transistor  

NASA Astrophysics Data System (ADS)

A voltage-biased metal immersed in an aqueous electrolyte attracts ions from the solution, causing the accumulation of a diffuse layer of charge close to its surface. This layer is called the Debye-Huckel layer, or double layer. For a non-reactive electrode, the electric double-layer (EDL) presents a capacitive electrical impedance, which depends non-linearly on the voltage applied across it. We present a novel transistor whose transduction element is the EDL capacitance, which allows electronic gating of a 50 MHz signal at frequencies close to 1 MHz. The transistor comprises three terminals: a pair of nanofabricated interdigitated electrodes (IDEs) embedded in an electrolyte-filled microfluidic channel, and a third, gating Ag/AgCl electrode in the same fluid volume. We demonstrate direct gating of the transistor with the Debye layer, and make use of the device to measure the voltage dependence of the EDL capacitance over a broad range of electrode bias.

Fraikin, Jean-Luc; Requa, Michael; Stanton, Michael; Cleland, Andrew

2009-03-01

385

A heteroepitaxial perovskite metal-base transistor  

NASA Astrophysics Data System (ADS)

‘More than Moore’ captures a concept for overcoming limitationsin silicon electronics by incorporating new functionalitiesin 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, Takeaki; Hikita, Yasuyuki; Hwang, Harold Y.

2011-03-01

386

High Performance Airbrushed Organic Thin Film Transistors  

SciTech Connect

Spray-deposited poly-3-hexylthiophene (P3HT) transistors were characterized using electrical and structural methods. Thin-film transistors with octyltrichlorosilane treated gate dielectrics and spray-deposited P3HT active layers exhibited a saturation regime mobility as high as 0.1 cm{sup 2} V{sup -1} s{sup -1}, which is comparable to the best mobilities observed in high molecular mass P3HT transistors prepared using other methods. Optical and atomic force microscopy showed the presence of individual droplets with an average diameter of 20 {micro}m and appreciable large-scale film inhomogeneities. Despite these inhomogeneities, near-edge x-ray absorption fine structure spectroscopy of the device-relevant channel interface indicated excellent orientation of the P3HT.

Chan, C.; Richter, L; Dinardo, B; Jaye, C; Conrad, B; Ro, H; Germack, D; Fischer, D; DeLongchamp, D; Gunlach, D

2010-01-01

387

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

388

HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS.  

SciTech Connect

Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department.

BEN-ZVI, ILAN, DAYRAN, D.; LITVINENKO, V.

2005-08-21

389

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

390

Operation of Graphene Transistors at GHz Frequencies  

Microsoft Academic Search

Top-gated graphene transistors operating at high frequencies (GHz) have been\\u000afabricated and their characteristics analyzed. The measured intrinsic current\\u000again shows an ideal 1\\/f frequency dependence, indicating an FET-like behavior\\u000afor graphene transistors. The cutoff frequency fT is found to be proportional\\u000ato the dc transconductance gm of the device. The peak fT increases with a\\u000areduced gate length, and

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

2008-01-01

391

Superconductive magnetoelectric field-effect transistor  

NASA Astrophysics Data System (ADS)

A transistor-like three-terminal superconducting device-the superconductive magnetoelectric field-effect transistor (SMET)-is described. The SMET represents a field-controlled Josephson device with its control based on the magnetoelectric effect. The device is characterized by a very high input-output isolation because the input is strictly voltage-controlled. As such, it may be useful for interconnecting voltage-controlled semiconductor electronics with current-controlled superconducting devices. The design considerations are reviewed, and preliminary experimental results are presented. Possible other practical applications are also discussed.

Hsiang, Thomas Y.; Sobolewski, Roman

1989-05-01

392

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

393

Premature switching in graphene Josephson transistors  

NASA Astrophysics Data System (ADS)

We investigate electronic transport in single layer graphene coupled to superconducting electrodes. In these Josephson transistors, we observe significant suppression in the critical current Ic and large variations in the product IcRn in comparison to theoretical predictions in the ballistic limit. We show that the depression of Ic can be explained by premature switching in underdamped Josephson junctions described within the resistively and capacitively shunted junction (RCSJ) model. By considering the effect of premature switching and dissipation, the calculated gate dependence of product IcRn agrees with experimental data. Our discovery underscores the crucial role of thermal fluctuations in electronic transport in graphene Josephson transistors.

Miao, Feng; Bao, Wenzhong; Zhang, Hang; Lau, Chun Ning

2009-07-01

394

An electrochemical transistor using a solid electrolyte  

NASA Astrophysics Data System (ADS)

Transistor action has been observed at elevated temperatures (800 C) with a structure composed of two ceramic ZrO2 electrochemical cells separated by an enclosed volume. One cell emits O2 from an ambient atmosphere into the volume (base region) where it is collected and returned to the ambient by the opposing cell. Electrical operation can be understood in terms of the current limitation presented by the Pt cathode of the collector cell. Small signal voltage, current, and power amplification are observed with a frequency response limited by the double-layer capacity of the collector. This approach to transistor action should be applicable to other solid-electrolyte systems.

Hetrick, R. E.; Vassell, W. C.

1980-09-01

395

Trap-limited transport in rubrene transistors  

NASA Astrophysics Data System (ADS)

The charge carrier mobility in the transport channel of an organic transistor is estimated within the framework of a trap-and-release model. The model accounts for the observed dependence of the mobility on the dielectric constant ? of the gate insulator. This dependence is attributed to both the effective mass of the carrier and the energetic depth of transport traps due to interface defects being functions of V. These results are used to describe the critical role of the interface between the organic semiconductor and the dielectric material in governing charge transport in organic transistors.

Konezny, S. J.; Bussac, M. N.; Zuppiroli, L.

2009-12-01

396

High-gain MOS tunnel emitter transistors  

NASA Astrophysics Data System (ADS)

Tunnel emitter transistors (TETs) are promising devices for high-current-density, high-frequency applications. The excellent CMOS compatibility of the TET makes it an ideal candidate to replace the bipolar junction transistors in BiCMOS technology; however, many properties of the TET are still under investigation. In this paper we present TETs with the highest current gain ever reported, 500-800. The effect of oxide quality on device performance is also described, and how the device characteristics can be improved by post-metallization annealing. Finally, we observe enhanced gain due to collector-emitter avalanching.

Aderstedt, Erik; Medugorac, Igor; Lundgren, Per

2002-04-01

397

Ultra low-voltage, rail-to-rail input\\/output stage Operational Transconductance Amplifier (OTA) with high linearity and its application in a GmC filter  

Microsoft Academic Search

This paper presents an ultra low-voltage, rail-to-rail input\\/output stage Operational Transconductance Amplifier (OTA) which uses quasi floating gate input transistors. This OTA works with ±0.3v and consumes 57¿w. It has near zero variation in small\\/large-signal behavior (i.e. transconductance and slew rate) in whole range of the common mode voltage of input signals. Using source degeneration technique for linearity improvement, make

Farzan Rezaei; Seyed Javad Azhari

2010-01-01

398

45 GHz distributed amplifier with a linear 6Vpp output for a 40 Gb\\/s LiNbO3 modulator driver circuit  

Microsoft Academic Search

We developed a coplanar waveguided-type distributed amplifier for a LiNbO3 modulator driver (LN driver) using double-doped AlGaAs\\/InGaAs\\/AlGaAs-pseudomorphic High Electron Mobility Transistors (p-HEMTs). By using a stabilization and impedance control technique, we obtained a 45 GHz bandwidth for coplanar waveguided (CPW) lines with a 600 ?m thick substrate and 54 GHz bandwidth for grounded coplanar waveguided (GCPW) lines with a 75

H. Shigematsu; N. Yoshida; M. Sato; N. Hara; T. Hirose; Y. Watanabe

2001-01-01

399

Charge amplifier with bias compensation  

DOEpatents

An ion beam uniformity monitor for very low beam currents using a high-sensitivity charge amplifier with bias compensation. The ion beam monitor is used to assess the uniformity of a raster-scanned ion beam, such as used in an ion implanter, and utilizes four Faraday cups placed in the geometric corners of the target area. Current from each cup is integrated with respect to time, thus measuring accumulated dose, or charge, in Coulombs. By comparing the dose at each corner, a qualitative assessment of ion beam uniformity is made possible. With knowledge of the relative area of the Faraday cups, the ion flux and areal dose can also be obtained.

Johnson, Gary W. (Livermore, CA)

2002-01-01

400

Inverting Amplifier with Current Input  

NSDL National Science Digital Library

This animated gif illustrates the changing voltages a conventional inverting amplifier when it receives input from a current source rather than a voltage source. Notice that the input resistor does not offer any impedance. Voltages and parts of the circuit of this 3-D animated gif are highlighted with different colors. Current is displayed by green arrows indicating directional flow. The animation requires a Web browser or other video player software capable of displaying gif animations.Other 3-D Circuit Animations can be seen here.

2009-11-23

401

Comparative study of mathematically modelled High Electron Mobility Transistors and silicon nanowire transistors  

Microsoft Academic Search

This work concentrates on the mathematical modeling of High Electron Mobility Transistors (HEMTs). Fermi-Dirac distribution characteristics of HEMTs and Silicon Nano-wire Transistors (SNWTs) were compared. Our mathematical modelling involves study of V-I characteristics, Electric field versus Drift velocity characteristics, 1D electron density versus position characteristics, transconductance versus gate-source voltage characteristics, unity gain cut off frequency versus gate-length characteristics, mobility versus

S. Neema Menon; K. A. Narayanankutty

2011-01-01

402

Field-effect transistor self-electrooptic effect device: integrated photodiode, quantum well modulator and transistor  

Microsoft Academic Search

The authors propose and demonstrate the integration of a photodiode, a quantum-confined Stark-effect quantum-well optical modulator, and a metal-semiconductor field-effect transistor (MESFET) to make a field-effect transistor self-electrooptic effect device. This integration allows optical inputs and outputs on the surface of a GaAs-integrated circuit chip, compatible with standard MESFET processing. To provide an illustration of feasibility, the authors demonstrate signal

D. A. B. Miller; M. D. Feuer; T. Y. Chang; S. C. Shunk; J. E. Henry; D. J. Burrows; D. S. Chemla

1989-01-01

403

Field Effect Transistor Sensitive to Dipolar Molecules.  

National Technical Information Service (NTIS)

A field effect transistor with metal gate suspended above the gate insulator has been fabricated. Fluid samples can freely penetrate into the gap formed between the metal and the insulator. If the molecules carry an electrical dipole, they will alter the ...

G. F. Blackburn M. Levy J. Janata

1983-01-01

404

Premature switching in graphene Josephson transistors  

Microsoft Academic Search

We investigate electronic transport in single layer graphene coupled to superconducting electrodes. In these Josephson transistors, we observe significant suppression in the critical current Ic and large variations in the product IcRn in comparison to theoretical predictions in the ballistic limit. We show that the depression of Ic can be explained by premature switching in underdamped Josephson junctions described within

Feng Miao; Wenzhong Bao; Hang Zhang; Chun Ning Lau

2009-01-01

405

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

406

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

407

Evaporated Silicon Thin-Film Transistors.  

National Technical Information Service (NTIS)

The method of fabrication, the theory and properties of evaporated silicon thin-film transistors are discussed. The device consists of a p-type silicon film (0.5-2 microns thick) on a sapphire substrate, with aluminum source-drain electrodes evaporated on...

C. A. T. Salama L. Young

1966-01-01

408

Evaporated Silicon Thin-Film Transistors.  

National Technical Information Service (NTIS)

Preliminary results on thin-film transistors having evaporated silicon films on sapphire are described. The silicon is evaporated first onto the sapphire substrate and is followed by the aluminum source-drain electrodes. The silicon oxide SiOx insulator i...

C. A. T. Salama L. Young

1965-01-01

409

Transient Response of Graded-Base Transistors.  

National Technical Information Service (NTIS)

Basic transient properties of graded-base transistor have been examined in terms of the minority-carrier distribution in the base region, subject to the restricting conditions of a one-dimensional device geometry and low injection. The mathematical expres...

G. L. Salton

1964-01-01

410

Dynamics of Transistor Negative-Resistance Circuits  

Microsoft Academic Search

A general method is presented for calculating approximately the behavior of many nonlinear circuits by dividing the region of operation into subregions, within each of which the circuit may be considered linear to a good approximation. The method is applied to a high-speed transistor switching circuit as an illustrative example.

B. G. Farley

1952-01-01

411

Transistor sizing for low power CMOS circuits  

Microsoft Academic Search

A direct approach to transistor sizing for minimizing the power consumption of a CMOS circuit under a delay constraint is presented. In contrast to the existing assumption that the power consumption of a static CMOS circuit is proportional to the active area of the circuit, it is shown that the power consumption is a convex function of the active area.

Manjit Borah; Robert Michael Owens; Mary Jane Irwin

1996-01-01

412

Ion-selective organic electrochemical transistors.  

PubMed

Ion-selective organic electrochemical transistors with sensitivity to potassium approaching 50 ?A dec(-1) are demonstrated. The remarkable sensitivity arises from the use of high transconductance devices, where the conducting polymer is in direct contact with a reference gel electrolyte and integrated with an ion-selective membrane. PMID:24862110

Sessolo, Michele; Rivnay, Jonathan; Bandiello, Enrico; Malliaras, George G; Bolink, Henk J

2014-07-01

413

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

414

Individual SWCNT based ionic field effect transistor  

Microsoft Academic Search

Here we report that the ionic current through a single-walled carbon nanotube (SWCNT) can be effectively gated by a perpendicular electrical field from a top gate electrode, working as ionic field effect transistor. Both our experiment and simulation confirms that the electroosmotic current (EOF) is the main component in the ionic current through the SWCNT and is responsible for the

Pei Pang; Jin He; Jae Hyun Park; Predrag Krstic; Stuart Lindsay

2011-01-01

415

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

416

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

417

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

418

Single electron transistor in aqueous media.  

PubMed

A gold nanoparticle necklace array spanning a ?30-micrometer-wide channel shows a robust coulomb blockade effect at room temperature with a threshold of 1V in air. When this device is operated in the aqueous solution, a gain of ?130 fold in conductance is obtained in electrochemical gating, significantly higher than other nanomaterial-based electrochemical transistors. PMID:23653239

Yu, Chichao; Lee, Seung-Woo; Ong, Jason; Moore, David; Saraf, Ravi F

2013-06-11

419

Radiation Damage In Advanced Bipolar Transistors  

NASA Technical Reports Server (NTRS)

Report describes measurements of common-emitter current gains (hFE) of advanced bipolar silicon transistors before, during, and after irradiation with 275-MeV bromine ions, 2.5-MeV electrons, and conductivity rays from cobalt-60 atoms.

Zoutendyk, John A.; Goben, Charles A.; Berndt, Dale F.

1989-01-01

420

Analytical Theory of Graphene Nanoribbon Transistors  

Microsoft Academic Search

Graphene has emerged as one of the most promising materials to address scaling challenges in the post silicon era. A simple model for graphene nanoribbon field-effect transistors (GNRFETs) is developed for treating the effects of edge bond relaxation, the third nearest neighbor interaction, and edge scattering, all of which are pronounced in GNRFETs, but not in carbon nanotube FETs.

Pei Zhao; Mihir Choudhury; Kartik Mohanram; Jing Guo

2008-01-01

421

High Performance Crystalline Organic Transistors and Circuit.  

National Technical Information Service (NTIS)

We have examined the best available small molecule crystalline organic semiconductors as active layers in thin-film transistors. We have optimized the field-induced conductance, a figure of merit that will relate directly to circuit speeds. A simple figur...

A. Dodabalapur

2011-01-01

422

Pressure sensitive organic field effect transistor  

Microsoft Academic Search

Thin films of organic semiconductor copper phthalocyanine (CuPc) and Al were deposited in sequence by vacuum evaporation on a glass substrate with Ag source and drain electrodes. The effect of pressure on the properties of the fabricated field effect transistor (FET) with metal (aluminum) – semiconductor (copper phthalocyanine) Schottky junction was investigated. It was observed that the drain–source resistance of

Kh. S. Karimov; M. Saleem; M. Mahroof-Tahir; T. A. Khan; Adam Khan

2010-01-01

423

X-Ray Inspection of Transistors  

NASA Technical Reports Server (NTRS)

Component holder speeds examination of matched pairs. Transistors are oriented for two perpendicular x-ray views. Second view obtained by simply flipping block around corner near components, while corner remains in contact with film. Procedure allows inspection of up to 50 pairs - two views of each pair - on single x-ray film in same time previously required for 1 unmounted pair.

Hubbard, W. P.

1983-01-01

424

Thermal Noise in Field-Effect Transistors  

Microsoft Academic Search

The limiting noise mechanism in field-effect transistors is thermal noise of the conducting channel. The noise can be represented by a current generator ¿i2 in parallel to the output. The value of i2 is calculated; for zero drain voltage the noise corresponds to thermal noise of the drain conductance, and for other bias conditions the noise at a given gate

A. van der Ziel

1962-01-01

425

High-Frequency Compensation of Transistors.  

National Technical Information Service (NTIS)

If a relatively small collector load resistor is used, so that the gain of a transistor stage is low, the addition of a peaking coil yields substantial improvements in bandwidth or rise time. Still further improvements result from the use of a peaking cap...

S. Deutsch J. G. Corbellini D. L. Greenberg A. M. Horn

1964-01-01

426

Indium Phosphide for High Frequency Power Transistors.  

National Technical Information Service (NTIS)

This report covers the first year of studies aimed at determining the utility of InP for fabricating power microwave field effect transistors (FET). The initial phase of the work was concentrated on developing the technology necessary to complete a power ...

V. L. Wrick G. W. Eldridge R. C. Clarke M. C. Driver

1979-01-01

427

Indium phosphide for high frequency power transistors  

Microsoft Academic Search

This report covers the first year of studies aimed at determining the utility of InP for fabricating power microwave field effect transistors (FET). The initial phase of the work was concentrated on developing the technology necessary to complete a power FET based on current design philosophy. Ion implantation and vapor phase epitaxy (VPE) results are presented as a means for

V. L. Wrick; G. W. Eldridge; R. C. Clarke; M. C. Driner

1979-01-01

428

Trapping Effects in Organic Thin Film Transistors  

Microsoft Academic Search

We report the fabrication of pentacene thin film transistors with a mobility of 2.17 cm2\\/Vs which is challenging amorphous silicon. Next to device mobility, large hysteresis in the IV characteristics has been an obstacle for the design of large organic circuits in the past. It is a key success factor for optimization and widespread application of organic devices to understand

C. Erlen; F. Brunetti; P. Lugli; M. Fiebig; S. Schiefer; B. Nickel

2006-01-01

429

Gate-controlled punch through transistor  

Microsoft Academic Search

Operation of the gate-controlled punch through transistor is demonstrated in this paper. The characteristics of the device are simulated using SILVACO atlas device simulator. This device shows high voltage, high operation frequency, and low noise properties. This punch through device can be used in high power control circuit, and also can be used for fast analog circuits for multiplication, squaring

Xiangli Li; Huadian Pan; Bogdan M. Wilamowski

2003-01-01

430

Integrated ytterbium-Raman fiber amplifier.  

PubMed

An integrated ytterbium-Raman fiber amplifier architecture is proposed for power scaling of a Raman fiber laser. It is an ytterbium (Yb) fiber amplifier seeded with a double or multiple wavelength laser and followed by a passive Raman fiber. The bluest wavelength light gets amplified in the Yb fiber and the power is transferred to redder wavelengths in the following Raman fiber. A proof of principle experiment demonstrates a 300 W all-fiber linearly polarized single mode amplifier at 1120 nm with an optical efficiency of 70%, limited only by available pump power. The amplifier consists of 4 m of Yb-doped fiber and 20 m of germanium-doped fiber, and seeded with a laser emitting at 1070 and 1120 nm. The power evolution of the 1070 and 1120 nm light inside the amplifier is investigated, both numerically and experimentally. The possibility of power scaling to over kilowatt levels is discussed. PMID:24686642

Zhang, Lei; Jiang, Huawei; Cui, Shuzhen; Feng, Yan

2014-04-01

431

A dc amplifier for nuclear particle measurement  

NASA Technical Reports Server (NTRS)

A monolithic preamplifier-postamplifier combination has been developed for use with solid state particle detectors. The direct coupled amplifiers employ interdigitated n-channel JFET's, diodes, and diffused resistors. The circuits developed demonstrate the feasibility of matching the performance of existing discrete component designs. The fabrication procedures for the monolithic amplifier fabrication are presented and the results of measurements on a limited number of sample amplifiers are given.

Macnee, A. B.; Masnari, N. A.

1978-01-01

432

Surpassing the Amplifier Limit for Force Detection  

NASA Astrophysics Data System (ADS)

A force-measuring system composed of a macroscopic harmonic oscillator, mechanical-electrical transducer, and linear amplifier is described and the sensitivity is calculated for a "back-action evasion" mode of operation. It is shown that it is possible to surpass the standard amplifier limit with this device, and the specific requirements to do so are given. These results may also apply to a quantum-limited amplifier and thus give the requirements to perform quantum-nondemolition measurements.

Bocko, Mark F.; Johnson, Warren W.

1982-05-01

433

High power RF amplifier's new nonlinear models  

Microsoft Academic Search

By carefully analysis measured data of power amplifier, this paper presents three new models. Model A uses Saleh function in traditional orthogonal bandpass model to increase accuracy. Model B uses an inverse tangent function to model RF power amplifier's AM-AM nonlinear behavior. Model C uses inverse tangent function in traditional orthogonal bandpass model to model power amplifier's AM-AM and AM-PM

Xing-Bin Zeng; Qian-Miao Hu; Jia-Ming He; Qiu-Ping Tu; Xiao-Jun Yu

2005-01-01

434

Retrodiction for optical attenuators, amplifiers, and detectors  

SciTech Connect

The transformation that an attenuator makes on the state of an optical field is the time reverse of that of an amplifier. Thus predicting the output state for an amplifier is equivalent to retrodicting the input state of an attenuator. We explore the consequences of this equivalence for simple optical quantum communication channels. One counterintuitive consequence is that the mean number of photons sent into an amplifier as retrodicted from a measurement of the number of output photons does not include the contribution of the amplifier noi0008.

Jedrkiewicz, Ottavia; Loudon, Rodney [Department of Electronic Systems Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Jeffers, John [Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

2004-09-01

435

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

436

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 amplifer circuit includes a first operational amplifier with a first feedback loop which includes a second, inverting operational amplifier in a second feedstock 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 is offset by a compensating break point or zero.

Brookshier, W.

1985-02-08

437

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

438

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

439

High Performance Power Amplifiers Utilizing Novel Balun Design Techniques  

NASA Astrophysics Data System (ADS)

In this PhD. research, a new power amplifier architecture is introduced. This work develops the push-pull architecture into a multifunctional matching network and combiner to create a high power, high efficiency, linear power amplifier (PA) that operates over a wide bandwidth. The traditional push-pull architecture uses an input balun to split a single ended signal into a differential signal, amplify it, and recombine it. This new technique realizes this architecture as a planar, hybrid, PA in X band. The first contribution of this work is the development of planar Marchand baluns that operate over a wide bandwidth. An analysis technique is developed and broadside coupled, Marchand baluns in an inhomogeneous medium are employed. These baluns operate over a bandwidth from 5 to 26 GHz with amplitude and phase imbalances less than 0.5 dB and 5 °, respectively. The even and odd mode behavior of the Marchand balun is utilized to provide harmonic matching for the PA. The balun inherently presents an open circuit to common mode signals at its center frequency. This is utilized to match the second harmonic to an open circuit condition. A band-stop filter is used as a harmonic trap to match the third harmonic to a short circuit. This achieves inverse class F matching for high efficiency operation. This network simultaneously acts as a combiner and matching network for high power and efficiency. A prototype PA was fabricated to prove this concept and achieves a saturated output power, Psat, greater than 33 dBm and a power added efficiency, PAE, greater than 62% over the bandwidth from 9.7 to 10.3 GHz. This technique was refined to operate over a wide bandwidth. The harmonic trap was removed and the out-of-band behavior of the balun was used to provide the short circuit matching at the third harmonic. A prototype PA was fabricated that achieved a 1 dB compressed power, P1dB, and PAE greater than 40 dBm and 55% respectively over the band from 8 to 12 GHz. Finally, the technique was extended to combine power from four transistors by the development of a 4-to-1 balun. A prototype PA was fabricated to prove this concept and achieves a P1dB and PAE greater than 43 dBm and 55% over the band from 8 to 12 GHz.

Stameroff, Alexander Nicholas

440

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

441

Optical latches using optical amplifiers  

NASA Astrophysics Data System (ADS)

Optical latches are important for a wide range of applications including communication systems, optical logic systems, optical random access memory (RAM) and encryption. All optical logic operations using quantum dot (QD) based semiconductor optical amplifier (SOA) and Mach-Zehnder interferometer (MZI) have been studied. The building block of an optical latch such as NAND gate has been fabricated and their operation experimentally demonstrated at ~ 80 GHz. A rate equation model has been developed for the QD-SOA-MZI and it has been used to analyze the Boolean logic operation. The model has been used to analyze the Set-Reset (S-R) latch and the D-Flip-Flop (DFF) devices. The DFF is the basic device for building larger logic circuits. The results show that the latches would work to speeds of ~ 250 Gb/s.

Li, Wenbo; Hu, Hongyu; Dutta, Niloy K.

2013-05-01

442

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

443

A single-supply Ku-band 1-W power amplifier MMIC with compact self-bias PHEMTs  

Microsoft Academic Search

In this letter, the design of a self-bias 1.8-mm AlGaAs\\/InGaAs\\/GaAs pseudomorphic high electron mobility transistor with a compact source capacitor for operation in Ku-band frequency is described. Based on the proposed device, a self-bias Ku-band 1-W two-stage power amplifier monolithic microwave integrated circuit (MMIC) is also demonstrated. Under a single bias condition of 8 V and 630 mA, the self-bias

Hong-Zhi Liu; Che-Hung Lin; Chen-Kuo Chu; Hou-Kuei Huang; Mau-Phon Houng; Ching-Hsueh Chang; Chang-Luen Wu; Chian-Sern Chang; Yeong-Her Wang

2006-01-01

444

A low-noise cryogenically-cooled 8–12 GHz HEMT Amplifier for future space applications  

Microsoft Academic Search

A two-stage 8–12 GHz (X-band) cryogenically-cooled Low-Noise Amplifier (LNA) has been developed with a commercial pseudomorphic\\u000a HEMT on AsGa substrate. In a first step, different commercial transistors have been fully characterized from 300 K to 20 K\\u000a using a new method to measure the four noise parameters. Preliminary results have allowed the selection of the best device.\\u000a This enabled the

Corinne Boutez; Paul Crozat; Valérie Danelon; Michel Chaubet; Pascal Febvre; Gérard Beaudin

1997-01-01

445

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

446

A high gain wide dynamic range transimpedance amplifier for optical receivers  

NASA Astrophysics Data System (ADS)

As the front-end preamplifiers in optical receivers, transimpedance amplifiers (TIAs) are commonly required to have a high gain and low input noise to amplify the weak and susceptible input signal. At the same time, the TIAs should possess a wide dynamic range (DR) to prevent the circuit from becoming saturated by high input currents. Based on the above, this paper presents a CMOS transimpedance amplifier with high gain and a wide DR for 2.5 Gbit/s communications. The TIA proposed consists of a three-stage cascade pull push inverter, an automatic gain control circuit, and a shunt transistor controlled by the resistive divider. The inductive-series peaking technique is used to further extend the bandwidth. The TIA proposed displays a maximum transimpedance gain of 88.3 dB? with the -3 dB bandwidth of 1.8 GHz, exhibits an input current dynamic range from 100 nA to 10 mA. The output voltage noise is less than 48.23 nV/?Hz within the -3 dB bandwidth. The circuit is fabricated using an SMIC 0.18 ?m 1P6M RFCMOS process and dissipates a dc power of 9.4 mW with 1.8 V supply voltage.

Lianxi, Liu; Jiao, Zou; Yunfei, En; Shubin, Liu; Yue, Niu; Zhangming, Zhu; Yintang, Yang

2014-01-01

447

Source follower or charge amplifier? An experimental comparison using a detector with integrated electronics  

SciTech Connect

In spectroscopy systems where the front-end amplifier is an external circuit, charge sensitive preamplifiers have been shown to be superior in performance with respect to voltage amplifiers as the first stage of amplification. The paper studies how these two circuit configurations behave when they are integrated in high resolution semiconductor detectors of very small capacitance. This paper for the first time compares, in this new condition, the stability of amplification of the source follower with the optimum behavior of the charge preamplifier, reporting its dependence on the detector bias, on the input transistor bias, and on the operating temperature. This paper then discusses the consequent loss in linearity and resolution that a system with an integrated source follower may undergo depending on the type of reset mechanism. The point of how the instabilities of the integrated feedback capacitance limit the performance of an integrated charge amplifier is also addressed. The analysis is based on experimental results obtained with the same detector with integrated electronics used in the two different configurations.

Sampietro, M.; Fasoli, L.; Bertuccio, G. [Politecnico di Milano (Italy). Dept. di Elettronica e Informazione] [Politecnico di Milano (Italy). Dept. di Elettronica e Informazione

1996-08-01

448

S-Band Solid State Amplifier Miniaturization.  

National Technical Information Service (NTIS)

The report describes the development of an all-solid-state integrated amplifier module having a CW output of 10 watts, 30 db gain and a 3 db bandwidth of 100 MHz centered at 2.25 GHz. The approach taken for fabricating the amplifier utilizes eight interdi...

W. E. Schaub

1970-01-01

449

LLNL/Lion Precision LVDT amplifier.  

National Technical Information Service (NTIS)

A high-precision, low-noise, LVDT amplifier has been developed which is a significant advancement on the current state of the art in contact displacement measurement. This amplifier offers the dynamic range of a typical LVDT probe but with a resolution th...

D. J. Hopkins

1994-01-01

450

Beam combining of ytterbium fiber amplifiers (Invited)  

Microsoft Academic Search

Fiber lasers are well suited to scaling to high average power using beam-combining techniques. For coherent combining, optical phase-noise characterization of a ytterbium fiber amplifier is required to perform a critical evaluation of various approaches to coherent combining. For wavelength beam combining, we demonstrate good beam quality from the combination of three fiber amplifiers, and we discuss system scaling and

Steven J. Augst; Jinendra K. Ranka; T. Y. Fan; Antonio Sanchez

2007-01-01

451

Oscillator or Amplifier With Wide Frequency Range  

NASA Technical Reports Server (NTRS)

Inductive and capacitive effects synthesized with feedback circuits. Oscillator/amplifier resistively tunable over wide frequency range. Feedback circuits containing operational amplifiers, resistors, and capacitors synthesize electrical effects of inductance and capacitance in parallel between input terminals. Synthetic inductance and capacitance, and, therefore, resonant frequency of input admittance, adjusted by changing potentiometer setting.

Kleinberg, L.; Sutton, J.

1987-01-01

452

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

453

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.

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

2012-01-01

454

Dual-range linearized transimpedance amplifier system  

DOEpatents

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) [Albuquerque, NM

2010-11-02

455

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

456

Amplified OTDR systems for multipoint corrosion monitoring.  

PubMed

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

457

Post pulse shutter for laser amplifier  

DOEpatents

Disclosed are an apparatus and method for quickly closing off the return path for an amplified laser pulse at the output of an amplifier so as to prevent damage to amplifiers and other optical components appearing earlier in the chain by the return of an amplified pulse. The apparatus consists of a fast retropulse or post pulse shutter to suppress target reflection and/or beam return. This is accomplished by either quickly placing a solid across the light transmitting aperture of a component in the chain, such as a spatial filter pinhole, or generating and directing a plasma with sufficiently high density across the aperture, so as to, in effect, close the aperture to the returning amplified energy pulse. 13 figs.

Bradley, L.P.; Carder, B.M.; Gagnon, W.L.

1981-03-17

458

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

459

High-performance InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor  

SciTech Connect

In this article, a novel InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor is first demonstrated. Though the valence band discontinuity at InGaP/GaAs heterojunction is relatively large, the addition of a {delta}-doped sheet between two spacer layers at the emitter-base (E-B) junction effectively eliminates the potential spike and increases the confined barrier for electrons, simultaneously. Experimentally, a high current gain of 25 and a relatively low E-B offset voltage of 60 mV are achieved. The offset voltage is much smaller than the conventional InGaP/GaAs pnp HBT. The proposed device could be used for linear amplifiers and low-power complementary integrated circuit applications.

Tsai, J.-H. [National Kaohsiung Normal University, Department of Electronic Engineering (China)], E-mail: jhtsai@nknucc.nknu.edu.tw; Chiu, S.-Y.; Lour, W.-S. [National Taiwan Ocean University, Department of Electrical Engineering (China); Guo, D.-F. [Air Force Academy, Department of Electronic Engineering (China)

2009-07-15

460

Modulation doped GaAs/AlGaAs field effect transistor  

NASA Astrophysics Data System (ADS)

To realize a depletion-mode modulation-doped field-effect transistor with high gate-length to depletion-depth ratio that is capable of providing high power gain at millimeter-wave frequencies, an ohmic gate or a heterojunction gate is used on the n-AlGaAs/GaAs layered structure, replacing the prior art Schottky-barrier metal gate. The depletion-mode operation is desirable for analog signal amplifying circuits as opposed to the enhancement-mode device commonly used for switching or digital circuits. In the case of Schottky-barrier gate, high aspect ratio structures naturally operate in the enhancement mode, hence the need for the change in the gate electrode structure.

Das, M. B.

1985-06-01

461

SiGe optoelectronic metal-oxide semiconductor field-effect transistor.  

PubMed

We propose a novel semiconductor optoelectronic switch that is a fusion of a Ge optical detector and a Si metal-oxide semiconductor field-effect transistor (MOSFET). The device operation is investigated with simulations and experiments. The switch can be fabricated at the nanoscale with extremely low capacitance. This device operates in telecommunication standard wavelengths, hence providing the surrounding Si circuitry with noise immunity from signaling. The Ge gate absorbs light, and the gate photocurrent is amplified at the drain terminal. Experimental current gain of up to 1000x is demonstrated. The device exhibits increased responsivity (approximately 3.5x) and lower off-state current (approximately 4x) compared with traditional detector schemes. PMID:17632630

Okyay, Ali K; Pethe, Abhijit J; Kuzum, Duygu; Latif, Salman; Miller, David A; Saraswat, Krishna C

2007-07-15

462

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

463

A programmable ferroelectric single electron transistor  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate a programmable ferroelectric single electron transistor using direct monolithic integration of a multi-gate III-V (In0.7Ga0.3As) quantum well field effect transistor with a composite ferroelectric (lead zirconium titanate) and high-k (hafnium dioxide) gate stack. A split gate electrode configuration allows electrical tuning of the tunnel barrier profile and reconfigurable programming of the device to operate in both classical and Coulomb blockade mode. The ferroelectric gate stack under the split gate electrode further allows non-volatile operation in both modes. This demonstration is a significant step towards realization of a non-volatile, programmable binary decision diagram logic circuit for ultra low power operation.

Liu, Lu; Narayanan, Vijay; Datta, Suman

2013-02-01

464

A silicon nanocrystal tunnel field effect transistor  

NASA Astrophysics Data System (ADS)

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 104 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; Drouin, Dominique; Pioro-Ladrière, Michel

2014-05-01

465

Graphene nanoribbon tunneling field effect transistors  

NASA Astrophysics Data System (ADS)

The electron-hole symmetry characteristic of graphene nanoribbons (GNRs) gives rise to the electron (hole) tunneling through valence (conduction) band states. By employing this property we have numerically investigated GNR field effect transistors with p+-type source and drain in the presence of a gate voltage-induced n-type channel using the non-equilibrium Green's function formalism. For long channels, the traditional FET-like I-V behavior is achieved, but at short channels, the sub threshold current opens up an oscillatory dependence on the gate voltage with a considerable amount of current of over 10-6 A. This is the characteristic current behavior of resonant tunneling transistors that exhibit regions of negative differential resistance. The calculated discrete density of states in the channel attributes this behavior to the constructed n-type channel island between p-type source and drain with thin barriers formed by the energy gap.

Mohamadpour, Hakimeh; Asgari, Asghar

2012-09-01

466

Air-stable ambipolar organic transistors  

NASA Astrophysics Data System (ADS)

The authors report on ambipolar organic transistors based on the soluble dithiolene derivative (diphenylethylenedithiolato)(1,3-dithiol-2-thione-4,5-dithiolato)nickel [Ni(dpedt)(dmit)]. Due to its small band gap, efficient injection of holes and electrons from gold source/drain electrodes is possible. Both carrier mobilities are estimated to be approximately equal with maximum value on the order of 10-4 cm2/V s. The transistors exhibit excellent ambient stability with a shelve lifetime exceeding 3 months. The pronounced stability of Ni(dpedt)(dmit) as well as of several other molecules studied here is correlated to their redox potential. The present findings can be used as a general guide towards design and synthesis of air-stable ambipolar/n-channel molecules.

Anthopoulos, Thomas D.; Anyfantis, G. C.; Papavassiliou, G. C.; de Leeuw, Dago M.

2007-03-01

467

Electrically switchable chiral light-emitting transistor.  

PubMed

Tungsten diselenide (WSe2) and related transition metal dichalcogenides exhibit interesting optoelectronic properties owing to their peculiar band structures originating from the valley degree of freedom. Although the optical generation and detection of valley polarization has been demonstrated, it has been difficult to realize active valley-dependent functions suitable for device applications. We report an electrically switchable, circularly polarized light source based on the material's valley degree of freedom. Our WSe2-based ambipolar transistors emit circularly polarized electroluminescence from p-i-n junctions electrostatically formed in transistor channels. This phenomenon can be explained qualitatively by the electron-hole overlap controlled by the in-plane electric field. Our device demonstrates a route to exploit the valley degree of freedom and the possibility to develop a valley-optoelectronics technology. PMID:24790028

Zhang, Y J; Oka, T; Suzuki, R; Ye, J T; Iwasa, Y

2014-05-16

468

Gold nanoparticle single-electron transistor simulation  

NASA Astrophysics Data System (ADS)

We suggest an approach for determining nanoobjects' energy spectra depending on its total electric charge. The approach was tested studying golden nanoparticles of different sizes surrounded by ligands of dodecanethiols. Quantum methods of Hartree-Fock and DFT were used to calculate energy spectra and capacitances for such gold nanoparticles consisting of up to 33 atoms of gold. Presence of "extra" levels in energy gap of nanobject's spectra was revealed. Also dodecanethiol SCH2(CH2)10CH3 ligands influence on the total capacitance and energy spectrum of molecular nanocluster was shown. Finally transport characteristics for gold nanocluster based molecular single-electron transistor (MSET) were calculated using the obtained energy spectra.The simple energy spectra structure model used in the present work may allow single-electron transistor (SET) simulation for larger molecular systems.

Gerasimov, Y. S.; Shorokhov, V. V.; Soldatov, E. S.; Snigirev, O. V.

2013-01-01

469

Driving pockels cells using avalanche transistor pulsers  

SciTech Connect

The purpose of this paper is to describe the current state of avalanche transistor based Pockels cell driver development at LLNL and to provide the reader with a set of useful design guidelines. A general description of the units is followed by a short section on the circuit design of avalanche transistor pulsers. A more detailed design guide is given. Techniques for delivering either {1/4} or {1/2} wave voltages to a Pockels cell are covered. Recently these units have been modified for use at repetition rates up to 10kHz. Operating at high repetition rates represents problems for both the driver and the Pockels Cell. Design solutions for the pulser are presented as well as discussion of Pockels cell acoustic resonance.

Fulkerson, E.S.; Norman, D.C.; Booth, R.

1997-05-28

470

Current reversals in p- n- p transistors  

NASA Astrophysics Data System (ADS)

p- n- p silicon bipolar junction transistors (BJTs) have received a greater attention recently in light of the emerging dilemma of performance and power requirements for bipolar VLSI. The current reversal phenomena due to the avalanche breakdown have been the focus of the study of advanced Si p- n- p BJTs in the past. However, a thorough study of current reversals in p- n- p transistors has not been presented yet. In this paper, we study the base and collector current reversals in the inverse mode and their associated physical mechanisms. The collector and base current reversals have been found when the device is operated with or without avalanche effect. Physical mechanisms have been proposed to interpret these phenomena.

Jang, Sheng-Lyang; Liu, Fong-Chin; Wu, Jim-Yat

1992-12-01

471

A Lithographic Process for Integrated Organic Field-Effect Transistors  

Microsoft Academic Search

This paper reports a photolithographic process for fabricating organic field-effect transistors which provides two layers of metal with arbitrary via placement, and optionally allows for subtractive lithographic patterning of the transistor active layer. The demonstrated pentacene transistors have a field-effect mobility of 0.1±0.05 cm2\\/(V·s). Parylene-C is used both as the gate dielectric and an encapsulation layer which allows for subtractive

Ioannis Kymissis; Akintunde Ibitayo Akinwande; Vladimir Bulovic

2005-01-01

472

Application of the Johnson criteria to graphene transistors  

NASA Astrophysics Data System (ADS)

For 60 years, the Johnson criteria have guided the development of materials and the materials choices for field-effect and bipolar transistor technology. Intrinsic graphene is a semi-metal, precluding transistor applications, but only under lateral bias is a gap opened and transistor action possible. This first application of the Johnson criteria to biased graphene suggests that this material will struggle to ever achieve competitive commercial applications.

Kelly, M. J.

2013-12-01

473

Organic thin film transistors with printed gate electrodes  

Microsoft Academic Search

We have fabricated pentacene thin film transistors on flexible polymeric substrates with gate electrodes prepared using a combination of microcontact printing and selective electroless plating of nickel. These transistors also employ a spin-coated polymer gate dielectric layer patterned by photolithography and dry etching and have a carrier mobility of 0.03 cm2\\/V-s, comparable to pentacene transistors with vacuum-deposited gate electrodes. For

Ute Zschieschang; Hagen Klauk; Marcus Halik; Gunter Schmid; Wolfgang Radlik; Werner Weber

2002-01-01

474

Charge separation techniques for irradiated pseudo-MOS SOI transistors  

Microsoft Academic Search

Pseudo-metal-oxide-semiconductor (MOS) silicon-on-insulator (SOI) transistors are used to study the total ionizing dose response of buried oxides. The concentrations of radiation-induced oxide-trap and interface-trap charge are separated using midgap and dual-transistor charge separation analysis techniques. Dual-transistor analysis is shown to be especially well suited for charge separation of pseudo-MOSFETs (?-MOSFETs) because the electron conduction mode of this simple point-contact device

B. Jun; D. M. Fleetwood; R. D. Schrimpf; X. Zhou; E. J. Montes; S. Cristoloveanu

2003-01-01

475

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

476

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

477

Field effect transistor based on protons as charge carriers  

Microsoft Academic Search

We demonstrated a field effect transistor based on the modulation of the proton flow in confined water-containing nanochannels. The device resembles an MOSFET transistor with the difference that the charge carriers here are ions (i.e. protons) instead of electrons. The effective cross-section of the conductive channels in the transistor is defined by the intensity of the electrical double layer and

J. Matovic; N. Adamovic; Z. Jakši?; U. Schmid

2010-01-01

478

TOPICAL REVIEW: Organic field-effect transistors using single crystals  

Microsoft Academic Search

Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of

Tatsuo Hasegawa; Jun Takeya

2009-01-01

479

Low-frequency noise in nanoscale ballistic transistors.  

PubMed

Low-frequency "1/f" noise is a major issue for nanoscale devices such at carbon nanotube transistors. We show that nanoscale ballistic transistors give voltage-dependent sensitivity to the intrinsic potential fluctuations from nearby charge traps. A distinctive dependence on gate voltage is predicted, without reference to the number of carriers. This dependence is confirmed by comparison with recent measurements of nanotube transistors. Possible ways of decreasing the noise are discussed. PMID:17212463

Tersoff, J

2007-01-01

480

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

481

Photonic bandgap materials: towards an all-optical micro-transistor  

NASA Astrophysics Data System (ADS)

We describe all-optical transistor action in photonic bandgap (PBG) materials doped with active atoms and analyse the advantages of this system over other all-optical transistor proposals. In the presence of a PBG material, a coherent laser beam with the frequency slightly detuned from the resonant atomic transition frequency can drive a collection of two-level atoms to an almost totally inverted state, a phenomenon strictly forbidden in ordinary vacuum. By varying the laser field intensity in the neighbourhood of a threshold value, it is possible to drive the atomic system through a transition from states in which the atoms populate preferentially the ground level to almost totally inverted states. In this process, the atomic system switches from a passive medium (highly absorptive) to a active medium (highly amplifying). The large differential gain exhibited by the atomic medium is very robust with respect to nonradiative relaxation and dephasing mechanisms. The switching action in a PBG material is not associated with operation near a narrow cavity resonance with conventional trade-off between switching time and switching threshold intensity. Rather it is associated with an abrupt discontinuity in the engineered broad-band electromagnetic density of states of the PBG material. We demonstrate all-optical transistor action in PBG materials by analysing the absorption spectrum of a second probe laser beam and we show that the probe beam experiences a substantial differential gain by slight intensity modulations in the control laser field. Under certain conditions, the fluctuations in the number of totally inverted atoms that contribute to the amplification process are strongly diminished (the statistics of the excited atoms becomes sub-Poissonian), which, in turn, determines a very low-noise regime of amplification.

John, Sajeev; Florescu, Marian

2001-11-01

482

High-power Yb:KYW picosecond regenerative amplifier for optical parametric amplifier pumping  

NASA Astrophysics Data System (ADS)

A 10 Hz, 10 mJ-level Yb:KYW diode-pumped regenerative amplifier for picosecond pulses at 1040 nm was developed. It will be used in front end of the PHELIX petawatt laser system at the Helmholtz-Center GSI to pump an optical parametric amplifier (OPA) for temporal contrast enhancement. In order to achieve a high temporal contrast, this regenerative amplifier is used as the pump source in a chirped-pulse amplification arrangement, which generates picosecond pulses before frequency doubling. For synchronization purposes, the seed pulses are derived from the femtosecond oscillator of the petawatt laser system, frequency shifted and pre-amplified by two fiber amplifiers.

João, C. P.; Körner, J.; Kahle, M.; Liebetrau, H.; Seifert, R.; Lenski, M.; Pastrik, S.; Hein, J.; Gottschall, T.; Limpert, J.; Figueira, G.; Bagnoud, V.

2011-05-01

483

Displacement-sensitive organic field effect transistor  

Microsoft Academic Search

Thin films of organic semiconductor copper phthalocynanine (CuPc) and Al were deposited in sequence by vacuum evaporation on a glass substrate with Ag source and drain electrodes. The effect of displacement on the properties of the fabricated field effect transistor with metal (aluminium)–semiconductor (copper phthalocyanine) Schottky junction was investigated. It was observed that the drain–source resistance of this organic field

Kh. S. Karimov; M. Saleem; M. Mahroof-Tahir; T. A. Qasuria; Adam Khan; T. A. Khan

2011-01-01

484

Displacement-sensitive organic field effect transistor  

Microsoft Academic Search

Thin films of organic semiconductor copper phthalocynanine (CuPc) and Al were deposited in sequence by vacuum evaporation on a glass substrate with Ag source and drain electrodes. The effect of displacement on the properties of the fabricated field effect transistor with metal (aluminium)–semiconductor (copper phthalocyanine) Schottky junction was investigated. It was observed that the drain–source resistance of this organic field

Kh. S. Karimov; M. Saleem; M. Mahroof-Tahir; T. A. Qasuria; Adam Khan; T. A. Khan

2012-01-01

485

Organic field-effect transistors using perylene  

Microsoft Academic Search

Organic thin-film field-effect transistors using organic semiconductor, perylene are fabricated, and electrical measurements are performed. The field-effect mobility of the device using perylene shows only p-type behavior while the electron and hole mobilities of its single crystal form are 5.5 and 0.5 cm2\\/Vs, respectively. Stacked layers of perlyene (a layer fabricated with low deposition rate followed by another layer with

Seong Hyun Kim; Yong Suk Yang; Jung Hun Lee; Jeong-Ik Lee; Hye Yong Chu; Hyoyoung Lee; Jiyoung Oh; Lee-Mi Do; Taehyoung Zyung

2003-01-01

486

Label free biosensing with carbon nanotube transistors  

NASA Astrophysics Data System (ADS)

As electronics reach nanometer size scales, new avenues of integrating biology and electronics become available. For example, nanoscale field-effect transistors have been integrated with single neurons to detect neural activity. Researchers have also used nanoscale materials to build electronic ears and noses. Another exciting development is the use of nanoscale biosensors for the point-of-care detection of disease biomarkers. This thesis addresses many issues that are relevant for electrical sensing applications in biological environments. As an experimental platform we have used carbon nanotube field-effect transistors for the detection of biological proteins. Using this experimental platform we have probed many of properties that control sensor function, such as surface potentials, the response of field effect transistors to absorbed material, and the mass transport of proteins. Field effect transistor biosensors are a topic of active research, and were first demonstrated in 1962. Despite decades of research, the mass transport of proteins onto a sensor surface has not been quantified experimentally, and theoretical modeling has not been reconciled with some notable experiments. Protein transport is an important issue because signals from low analyte concentrations can take hours to develop. Guided by mass transport modeling we modified our sensors to demonstrate a 2.5 fold improvement in sensor response time. It is easy to imagine a 25 fold improvement in sensor response time using more advanced existing fabrication techniques. This improvement would allow for the detection of low concentrations of analyte on the order of minutes instead of hours, and will open the door point-of-care biosensors.

Leyden, Matthew R.

487

Fully overheated single-electron transistor.  

PubMed

We consider the fully overheated single-electron transistor, where the heat balance is determined entirely by electron transfers. We find three distinct transport regimes corresponding to cotunneling, single-electron tunneling, and a competition between the two. We find an anomalous sensitivity to temperature fluctuations at the crossover between the two latter regimes that manifests in an exceptionally large Fano factor of current noise. PMID:20866990

Laakso, M A; Heikkilä, T T; Nazarov, Yuli V

2010-05-14

488

Polycrystalline silicon ion sensitive field effect transistors  

Microsoft Academic Search

We report the operation of polycrystalline silicon ion sensitive field effect transistors. These devices can be fabricated on inexpensive disposable substrates such as glass or plastics and are, therefore, promising candidates for low cost single-use intelligent multisensors. In this work we have developed an extended gate structure with a Si3N4 sensing layer. Nearly ideal pH sensitivity (54 mV\\/pH) and stable

F. Yan; P. Estrela; Y. Mo; P. Migliorato; H. Maeda; S. Inoue; T. Shimoda

2005-01-01

489

1\\/f noise in advanced CMOS transistors  

Microsoft Academic Search

Complementary metal-oxide-semiconductor (CMOS) technology is dominant in the microelectronics industry for a wide range of applications, including analog, digital, RF, and sensor systems. The advantages of silicon CMOS technology compared to bipolar technology as well as transistors in other semiconductors is well-established. CMOS technology scaling has been a main drive for continuous progress in the silicon based semiconductor industry over

Yael Nemirovsky; Dan Corcos; Igor Brouk; Amikam Nemirovsky; Samir Chaudhry

2011-01-01

490

A versatile, ion implanted bipolar transistor  

Microsoft Academic Search

This paper describes the physical properties of arsenic and boron implanted silicon which have enabled bipolar transistors with hFEfrom 20 to > 1000 and with fTfrom 1.5 GHz to 7.7 GHz to be made. The process, which is capable of producing extremely uniform distributions of electrical parameters (e.g., hFE112 ± 1.2) is clearly extendable to a broad distribution of possible

R. J. Scavuzzo; R. S. Payne; K. H. Olson; J. M. Nacci; R. A. Moline

1972-01-01

491

Fully ion-implanted bipolar transistors  

Microsoft Academic Search

Technology for the fabrication of fully ion-implanted bipolar transistors with arsenic emitters and boron bases is described. This technology results in extremely uniform distributions of electrical parameters, e.g,, hFE= 113 with a standard deviation of 1.3 across a wafer. In addition, it can produce a wide range of doping profiles and hence, a wide range of device performance. Using very

R. S. Payne; R. J. Scavuzzo; K. H. Olson; J. M. Nacci; R. A. Moline

1974-01-01

492

Photo carrier generation in bipolar transistors  

Microsoft Academic Search

Anomalous substrate currents have been observed in SiGe bipolar NPN-transistors, dependent on the collector bias, at high current levels. These currents appear to originate from light that is generated in the collector base junction when it is reverse biased. This light generates electron hole pairs in the n+ buried layer-substrate diode, yielding a considerable substrate current. This paper will show

Johan H. Klootwijk; Jan W. Slotboom; M. S. Peter; Victor Zieren; Dick B. de Mooy

2002-01-01

493

VBIC95: an improved bipolar transistor model  

Microsoft Academic Search

A new compact bipolar transistor model for circuit simulators that has already received widespread support in the industry, is considered. The model, VBIC95, was constructed to be the industry standard replacement for the aging SPICE Gummel-Poon model (SGP). Users of the 20-year-old SGP model have found it to be inadequate in representing, many of the physical effects important in modern

F. Najm

1996-01-01

494

All-polymer field effect transistors  

Microsoft Academic Search

Polymer field effect transistors (PFETs) were made from polymeric semiconductors, insulators and electrodes on flexible polymeric substrates. The authors present recent results of all-polymer FETs with conjugated polymers like poly(3-alkylthiophenes) as active semiconducting material. Highly resolved electrodes were patterned by lithography of conducting polymers. The on\\/off ratios exceed 1000 by far. The logic capability of the PFETs could be demonstrated

M. Schrodner; S. Sensfuss; H.-K. Roth; R.-I. Stohn; W. Clemens; A. Bernds

2002-01-01

495

A 500 MHz carbon nanotube transistor oscillator  

NASA Astrophysics Data System (ADS)

Operation of a carbon nanotube field effect transistor (FET) oscillator at a record frequency of 500 MHz is described. The FET was fabricated using a large parallel array of single-walled nanotubes grown by chemical vapor deposition on ST-quartz substrates. Matching of the gate capacitance with a series inductor enabled greater than unity net oscillator loop gain to be achieved at 500 MHz.

Pesetski, A. A.; Baumgardner, J. E.; Krishnaswamy, S. V.; Zhang, H.; Adam, J. D.; Kocabas, C.; Banks, T.; Rogers, J. A.

2008-09-01

496

Low-frequency noise in polymer transistors  

Microsoft Academic Search

The low-frequency noise (LFN) properties of field-effect transistors (FETs) using polymers as the semiconducting substrate material are investigated and explained in terms of the nonstationary mobility ? in the semiconducting polymer. In the frequency (f) range f<1 kHz it was found that 1\\/f noise prevails over other types of LFN in these polymer FETs (PFETs). The spectral density SI of

M. Jamal Deen; Ognian Marinov; S. Holdcroft; W. Woods

2001-01-01

497

Arsenic emitter high-performance transistor  

Microsoft Academic Search

Silicon n-p-n transistors with gain-bandwidth, fT, of 13 GHz and current gain ? of 280 have been fabricated by using arsenic capsule diffusion to produce the emitter region. Devices have been fabricated With the same epitaxial and diffusion processes up to emitter diffusion, and then emitter regions were formed by either arsenic or phosphorus diffusion. For the same mask geometry,

H. N. Ghosh; A. S. Oberai; M. B. Vora; J. J. Chang; M. L. Joshi; T. H. Yeh

1970-01-01

498

Controlling transistor threshold voltages using molecular dipoles  

NASA Astrophysics Data System (ADS)

We develop a theoretical model for how organic molecules can control the electronic and transport properties of an underlying transistor channel to whose surface they are chemically bonded. The influence arises from a combination of long-ranged dipolar electrostatics due to the molecular head groups as well as short-ranged charge transfer and interfacial dipole driven by equilibrium band alignment between the molecular backbone and the reconstructed semiconductor surface atoms.

Vasudevan, Smitha; Kapur, Neeti; He, Tao; Neurock, Matthew; Tour, James M.; Ghosh, Avik W.

2009-05-01

499

Dual Gated Silicon Nanowire Field Effect Transistors  

Microsoft Academic Search

Silicon Nanowire field effect transistors (SiNWFETs) are ideal candidates for basic sensing units. We report here on a top down fabrication process in SOI wafers yielding SiNWFETs. We operate the SiNWFETs in a liquid cell and control their operation with two gates: a liquid gate and a back gate. We compare the combined effects of the two gates (dual gating)

O. Knopfmacher; D. Keller; M. Calame; C. Schönenberger

2009-01-01

500

Silicon nanowire tunneling field-effect transistors  

Microsoft Academic Search

We demonstrate the implementation of tunneling field-effect transistors (TFETs) based on silicon nanowires (NWs) that were grown using the vapor-liquid-solid growth method. The Si NWs contain p-i-n+ segments that were achieved by in situ doping using phosphine and diborane as the n- and p-type dopant source, respectively. Electrical measurements of the TFETs show a band-to-band tunneling branch in the transfer

M. T. Björk; J. Knoch; H. Schmid; H. Riel; W. Riess

2008-01-01