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1

A Broadband Complementary Transistor Amplifier.  

National Technical Information Service (NTIS)

A two-stage NPN-PNP complementary transistor amplifier with great versatility over a broad frequency range is described herein. This circuit configuration provides high-input impedance and low-output impedance coupled with extremely stable gain characteri...

R. S. Hughes R. A. Mammano

1965-01-01

2

Design of powerful broadband transistorized amplifiers  

Microsoft Academic Search

The circumscribed mathematical model allows to design powerful broadband transistorized amplifiers (PBTA) by criterion of a minimum of technological losses of manufacture K6, and in case of using operating of monitoring cascades allows to allocate the most significant casual parameters of elements which, for example, can be chosen as, set up with the indicating, margins (borders) of their variations

A. V. Kolotvin; A. V. Pisanko; V. V. Maneev

2001-01-01

3

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

4

Gain Limitations of a Single-Transistor Voltage Amplifier  

NASA Astrophysics Data System (ADS)

The maximum voltage gain achievable with an amplifier, using only a single bipolar transistor, is shown to depend mainly on the power supply voltage Vcc. Textbooks show that the gain of an emitter follower amplifier is the product of the trans-conductance and the collector resistor, making it seem as though one can increase the gain indefinitely by choosing better transistors and/or larger resistors. However, to prevent saturation (and decreased gain) these parameters are not independent. Thus, the maximum possible gain Gmax is nearly independent of the transistor characteristics. For small signal one-transistor AC amplifiers, Gmax is found to be Gmax = Vcc/(nkT/q) = Vcc/(0.026 n Volts) at room temperature. Here n is the ideality factor of the base-emitter junction, a number that is typically between 1 and 2. For large signal AC amplifiers Gmax is reduced by a factor of two. Emitter stabilization reduces the maximum gain (in our example by a factor of ten) but extends the gain to DC, and makes it independent of temperature. It also allows for "universal" replacement transistors, requiring only a sufficiently high voltage rating, and a nearly linear current gain large compared to unity.

Penchina, Claude M.

2001-03-01

5

Thermoelectric energy scavenging from waste heat of power amplifier transistors  

Microsoft Academic Search

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

Kyoung Joon Kim; Marc Hodes

2009-01-01

6

Triple-mode single-transistor graphene amplifier and its applications.  

PubMed

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. As a result, the single-transistor graphene amplifier can operate in the common-source, common-drain, or frequency multiplication mode, respectively. This in-field controllability of the single-transistor graphene amplifier can be used to realize the modulation necessary for phase shift keying and frequency shift keying, which are widely used in wireless applications. It also offers new opportunities for designing analog circuits with simpler structure and higher integration densities for communications applications. PMID:20939515

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

2010-10-26

7

Development of a broadband microwave power transistor amplifier for the solar radio fast recording system  

Microsoft Academic Search

The designing principle and the technical characters of a broadband microwave power transistor amplifier for the solar radio fast recording system at Yunnan Observatory are described. The circuit schemes and the initial results measured for the amplifier are included.

Guoqiang Ghen

1996-01-01

8

An All-Transistor, 1Kilowatt, High-Gain, UHF Power Amplifier  

Microsoft Academic Search

An all-transistor power amplifier which delivers a cw power output of 1 kilowatt at 400 MHz has been designed and fabricated. In this design approach, a number of discrete transistors are connrected in parallel to form a power module, and the outputs of a quantity of modules are then combined to achieve the desired total output power. The discrete transistor

R. L. Bailey; W. P. Bennett; L. F. Heckman; I. E. Martin

1969-01-01

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

Importance of Harmonic Terminations in Performances of a Class-C UHF Transistor Power Amplifier  

Microsoft Academic Search

The influence of 2nd harmonic on the performances of an UHF class-C transistor power amplifier was determined. A matching circuit was designed, in which the reactive impedance termination presented at the second harmonic can be varied without affecting the impedance presented at the fundamental frequency. The main performance characteristics of the transistor power amplifier (output power, efficiency, intermodulation) were then

Ataollah Azizi; Shamsur R. Mazumdert; Fred E. Gardiol

1979-01-01

11

Phase noise reduction in microwave bipolar transistor amplifiers through active feedback  

Microsoft Academic Search

In this paper, we document the effects of low-frequency active feedback on the 1\\/f phase modulation (PM) noise of linear and compressed SiGe heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) amplifiers operating at 1GHz. Low noise, high frequency transistors manufactured by NEC were used in a common-emitter (CE) configuration and powered with DC batteries to ensure low

Matthew J. Luce; Eva S. Ferre-Pikal

2004-01-01

12

Realization and linearization of a hyperfrequency power amplifier implemented with bipolar transistors in class C polarization  

NASA Astrophysics Data System (ADS)

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 emitter polarization voltage related to the incident high frequency power. The circuit that elaborates the control signal is described. The results show the need to separate the stages.

Durand, Y.

1985-01-01

13

Highly linear RF CMOS amplifier and mixer adopting MOSFET transconductance linearization by multiple gated transistors  

Microsoft Academic Search

A highly linear CMOS RF amplifier and mixer circuits adopting MOSFET transconductance linearization by linearly superposing several common-source FET transistors in parallel, combined with some additional circuit techniques such as cascode for amplifier and harmonic tuning for mixer, are reported. Experimental result designed using above techniques shows IP3 improvements at given power consumption by as large as 10 dB for

Tae Wook Kim; Bonkee Kim; Kywro Lee

2003-01-01

14

Detector embedded device for continuous reset of charge amplifiers: choice between bipolar and MOS transistor  

NASA Astrophysics Data System (ADS)

This work discusses the criteria for the choice of the reset device in a charge amplifier whose front-end is integrated on high-resolution semiconductor detectors. The performances achievable using a bipolar or a MOS transistor as reset device are compared in terms of the linearity of the response and of the added noise as a function of the detector leakage current. The additional constraints in term of available technology and layout compatibility show the advantages of MOS transistors operated in sub-threshold mode.

Guazzoni, C.; Sampietro, M.; Fazzi, A.

2000-04-01

15

Analysis of multiple time scales in a transistor amplifier.  

PubMed

It was shown previously in an experiment that when high frequency signals (on the order of 1 MHz) were injected into this low frequency amplifier, the nonlinearities of the pn junctions caused period doubling, chaos, and very low frequency oscillations (on the order of 1 Hz). In this paper we present theory and simulations to explain the existence of the low frequency oscillations. PMID:15903547

Armstead, Douglas N; Carroll, Thomas L

2005-03-17

16

Transimpedance amplifiers for optical fiber systems based on common-base transistors  

Microsoft Academic Search

In this paper, the performances of common-emitter and common-base transimpedance amplifiers are compared. Frequency response, noise level, power consumption, and silicon area are the main parameters studied. It is shown that transimpedance preamplifiers based on common-base transistors present less peaking effects because the poles of the transimpedance gain are real in most practical cases. The noise figures for both common-emitter

Jaime Martinez-Castillo; Josd Silva-Martinez

1999-01-01

17

Characterization of surface- and buried-channel detection transistors for CCD on-chip amplifiers  

Microsoft Academic Search

Low noise floating-diffusion amplifiers, made in double and single layer membrane poly-Si technology, are characterized including scaling rules for the 1\\/f noise, thermal noise, 3 dB bandwidth and conversion gain. A comparison is made between buried- and surface-channel detection node transistors for various channel widths, lengths, and bias currents. A new method for measuring the total detection node capacitance is

Peter G. Centen; Edwin Roks

1997-01-01

18

Measurement of low-frequency base and collector current noise and coherence in SiGe heterojunction bipolar transistors using transimpedance amplifiers  

Microsoft Academic Search

Transimpedance amplifiers have been used for direct study of current noise in silicon germanium (SiGe) heterojunction bipolar transistors (HBT's) at different biasing conditions. This has facilitated a wider range of resistances in the measurement circuit around the transistor than is possible when using a voltage amplifier for the same kind of measurements. The ac current amplification factor h fe and

Staffan P. O. Bruce; L. K. J. Vandamme; Anders Rydberg

1999-01-01

19

40 GHz transimpedance amplifier with differential outputs using InP\\/InGaAs heterojunction bipolar transistors  

Microsoft Academic Search

High gain and bandwidth transimpedance amplifiers (TIA) are required for fiber optic receiver modules. This paper reports on the design, fabrication and characterization of a 40 Gbit\\/s TIA for SONET\\/SDH STS-768\\/STM-256 applications based on an InP\\/InGaAs single heterojunction bipolar transistor (SHBT) process developed at Vitesse Semiconductor Corporation (Vitesse Indium Phosphide Release 1 or VIP-1). This amplifier consists of a single-ended

Charles Q. Wu; Emilio A. Sovero; Bruce Massey

2002-01-01

20

Wide-band microwave amplifier realizations in microstrip employing a GaAs Schottky-barrier field-effect transistor  

Microsoft Academic Search

This work deals with the realization of two 4-8 GHz flat-gain amplifier designs in microstrip using a single GaAs Schottky-barrier field-effect transistor. Two aspects of microstrip amplifier realization are considered. The first aspect is accurate realization of required lumped and distributed circuit elements. The second involves detailed mathematical modelling of practical circuit elements, permitting computer analysis and optimization of complete

R. B. Watson Jr.

1976-01-01

21

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

ERIC Educational Resources Information Center

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

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

2009-01-01

22

TRANSISTORIZATION  

Microsoft Academic Search

Transistor and semiconductor diodes, compared with vacuum tubes in ; nucleonic instruments, offer the advantages of increased reliability, smaller ; size, and cooler operation. These elements are already replacing tubes ia all ; trigger and switching circuits in the field. Recently developed transistors open ; the way for transistorization of the remaining circuits basic a radiation ; detection systems. Problems

Goulding

1959-01-01

23

Power Amplifier (PA) Transistors Fatigue Life Prediction under ThermoMechanical Cyclic Loading  

Microsoft Academic Search

In this paper, a simulation procedure was established for the fatigue life prediction of transistor assembly system under thermo-mechanical cyclic loading condition. By combining non-linear finite element (FE) methodology and test data, the failure mechanisms of transistor assembly system in response to thermal cyclic loading condition were investigated. Anand material constitutive model was adopted to describe the behavior of solder

Jianjun Wang; Weiqun Peng; Wei Ren

2006-01-01

24

Monolithic ultra-broadband transimpedance amplifiers using AlGaAs\\/GaAs heterojunction bipolar transistors  

Microsoft Academic Search

Monolithic ultra-broadband transimpedance amplifiers are developed using AlGaAs\\/GaAs HBTs. To realize good amplifier performances, two factors are mentioned: an affordable HBT fabrication process using the self-aligned method and an optimized circuit design considering large signal operations. The developed HBT fabrication process achieves excellent uniformity in DC characteristics and the effect on amplifier microwave performances, derived from the discrete device uniformity,

Nobuo Nagano; Tetsuyuki Suzaki; Masaaki Soda; Kensuke Kasahara; Takeshi Takeuchi; Kazuhiko Honjo

1994-01-01

25

Burnout studies of X-band radar negative resistance transistor low noise amplifiers  

Microsoft Academic Search

GaAs FETs and HEMTs can be configured to give low noise, negative resistance microwave amplification. Such low noise amplifiers have the advantage of an inherent bypass path after device burnout. This feature is potentially useful in radar receiver applications. Test results for prototype LNAs are described, showing burnout energies comparable to those of conventional transmission mode amplifiers using similar devices.

D. K. Paul; P. Gardner

1992-01-01

26

Burnout studies of X-band radar negative resistance transistor low noise amplifiers  

NASA Astrophysics Data System (ADS)

GaAs FETs and HEMTs can be configured to give low noise, negative resistance microwave amplification. Such low noise amplifiers have the advantage of an inherent bypass path after device burnout. This feature is potentially useful in radar receiver applications. Test results for prototype LNAs are described, showing burnout energies comparable to those of conventional transmission mode amplifiers using similar devices. Bypass path losses after burnout are around 4 dB, approximately 20 dB less than for a failed transmission mode amplifier.

Paul, D. K.; Gardner, P.

1992-03-01

27

Observing transistor voltage waveform in high efficiency class-E HF\\/VHF\\/UHF power amplifiers  

Microsoft Academic Search

Class E amplifiers were introduced by the Sokals in the 70 s and, since then, numerous applications where higher efficiency was one of the key issues have seen the light. In this work a review of some useful and simple techniques to observe the collector\\/drain voltage waveform of the device was explained with examples. This work is really interesting for

Arturo Mediano; Kumar Narendra

2009-01-01

28

Remote lab for experiments on a small-signal bipolar-junction transistor amplifier  

Microsoft Academic Search

This paper demonstrate how to construct an advanced yet low cost remote lab for experiments fro an module in analogue electronics at an electrical engineering course at second year bachelor level. The remote lab is designed for running experiments on a normal BJT common emitter amplifier circuit, while maintaining the possibility for the students to use a wide range of

Dag A. H. Samuelsen; Olaf Hallan Graven

2011-01-01

29

DESIGN OF AN ULTRA-WIDEBAND, LOW-NOISE AMPLIFIER USING A SINGLE TRANSISTOR: A TYPICAL APPLICATION EXAMPLE  

Microsoft Academic Search

In this work, a design method of an Ultra-Wideband (UWB), low-noise amplifler (LNA) is proposed exerting the perfor- mance limitations of a single high-quality discrete transistor. For this purpose, the compatible (Noise F, Input VSWR Vi, Gain GT) triplets and their (ZS, ZL) terminations of a microwave transistor are exploited for the feasible design target space with the minimum noise

Salih Demirel; F. Gune; Ufuk Ozkaya

2009-01-01

30

Amplifier Distortion  

NASA Astrophysics Data System (ADS)

By definition, a high fidelity amplifier's instantaneous output voltage is directly proportional to its instantaneous input voltage. While high fidelity is generally valued in the amplification of recorded music, nonlinearity, also known as distortion, is desirable in the amplification of some musical instruments. In particular, guitar amplifiers exploit nonlinearity to increase both the harmonic content and sustain of a guitar's sound. I will discuss how both modifications in sound result from saturation of triode tubes and transistors. Additionally, I will describe the difference in the symmetry of saturation curves for transistors and tubes and the reason why tube guitar amplifiers are generally considered to be superior to solid-state amplifiers. Finally, I will discuss attempts to use solid-state electronics to replicate the sound of tube amplifiers.

Keeports, David

2006-12-01

31

UHF High-Power Low-Distortion Transistor Amplifier with High-Dielectric (epsilon\\/sub r\\/=39) Substrate  

Microsoft Academic Search

A hybrid-integrated UHF power amplifier has been designed and fabricated on high-dielectric (epsilon r=39) substrate. The amplifier was developed to replace TWTs in television transposers and provides a rated output peak power of 32W with low-distortion characteristic over the 650%~770 MHz frequency range.

Y. Kajiwara; T. Noguchi; T. Sugiura; H. Takamizawa; K. Hirakawa; K. Sasaki

1979-01-01

32

Investigation of silicon field-effect transistors in cryogenic amplifiers for radio frequency superconducting quantum interference devices  

SciTech Connect

We have prepared {ital n}-channel silicon field-effect transistors, which are capable of working at liquid helium temperatures (4.2 K) and used them in cooled preamplifiers for rf superconducting quantum interference device (SQUID) readout electronics. All metallizations of these transistors were made of niobium, to study the possibility of a further integration of a SQUID and FET on the same chip. Using the FETs in a cooled preamplifier together with a rf SQUID gradiometer, the flux noise of the system could be reduced by a factor of 3 compared to a room temperature low noise preamplifier. We have also performed calculations of a possible increase of the substrate temperature due to the power dissipation of the FET and have measured the cross talk between FET and SQUID. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Becker, T.; Mueck, M. [Institut fuer Schicht-und Ionentechnik, Forschungszentrum Juelich GmbH (KFA), 52425 Juelich (Germany); Heiden, C. [Institut fuer Angewandte Physik der Justus Liebig Universitaet, Heinrich-Buff-Ring 16, 35392 Giebetaen (Germany)

1995-05-01

33

Low noise tuned amplifier  

NASA Astrophysics Data System (ADS)

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

Kleinberg, L. L.

1984-03-01

34

Amplify Interest in STS.  

ERIC Educational Resources Information Center

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

Chiappetta, Eugene L; Mays, John D.

1992-01-01

35

UHF Integrated Power Amplifiers  

Microsoft Academic Search

This paper describes the development of integrated UHF power amplifiers using thin-film lumped elements and UHF power-transistor chips. Single-stage hybrid amplifier modules capable of delivering output powers up to 20 watts CW in the frequency range of 225-400 MHz are reported. In addition, broad-band hybrid amplifiers are discussed with 1-dB bandwidths of up to 40 percent in the same 225-400

W. E. Poole

1969-01-01

36

Field effect transistor-self electrooptic effect device (FET-SEED) differential transimpedance amplifiers for two-dimensional optical data links  

Microsoft Academic Search

A 4×18 two-dimensional array of GaAs FET-SEED (field effect transistor-self electrooptic effect device) differential transimpedence receivers has been fabricated for application in massively parallel optical data link board-to-board interconnections. Several FET-SEED receiver arrays were tested and displayed a mean response of ~0.7 mV\\/?W, and were capable of >100 Mbps per channel operation. The mean receiver sensitivity for a BER of

Robert A. Novotny; Michael J. Wojcik; Anthony L. Lentine; Leo M. F. Chirovsky; L. A. D'Asaro; M. W. Focht; G. Guth; K. G. Glogovsky; R. Leibenguth; M. T. Asom; J. M. Freund

1995-01-01

37

Novel WSi/Au T-shaped gate GaAs metal-semiconductor field-effect-transistor fabrication process for super low-noise microwave monolithic integrated circuit amplifiers  

SciTech Connect

A fully ion-implanted self-aligned T-shaped gate Ga As metal-semiconductor field-effect transistor (MESFET) with high frequency and extremely low-noise performance has been successfully fabricated for super low-noise microwave monolithic integrated circuit (MMIC) amplifiers. A subhalf-micrometer gate structure composed of WSi/Ti/Mo/Au is employed to reduce gate resistance effectively. This multilayer gate structure is formed by newly developed dummy SiON self-alignment technology and a photoresist planarization process. At an operating frequency of 12 GHz, a minimum noise figure of 0.87 dB with an associated gain of 10.62 dB has been obtained. Based on the novel FET process, a low-noise single-stage MMIC amplifier with an excellent low-noise figure of 1.2 dB with an associated gain of 8 dB in the 14 GHz band has been realized. This is the lowest noise figure ever reported at this frequency for low-noise MMICs based on ion-implanted self-aligned gate MESFET technology. 14 refs., 9 figs.

Takano, H.; Hosogi, K.; Kato, T. [Mitsubishi Electric Corp., Itami (Japan)] [and others

1995-05-01

38

A 12GHz High-Efficiency Tapered Traveling-Wave Power Amplifier With Novel Power Matched Cascode Gain Cells Using SiGe HBT Transistors  

Microsoft Academic Search

In this paper, we present the analysis, design, and implementation of an integrated power distributed amplifier (DA), fabricated in a low-cost 0.25-mum SiGe BiCMOS technology. The circuit consists of four novel inductively peaked cascode gain cells, which are capacitively coupled to the base line for power optimization and bandwidth enhancement. Due to the tapered collector line, no output termination resistor

Benjamin Sewiolo; Georg Fischer; Robert Weigel

2009-01-01

39

Class E amplifier with inductive clamp circuit  

Microsoft Academic Search

A class E RF amplifier, which can operate into any load conditions without need for other additional circuitry to protect transistors, is introduced. This is provided by a new topology which incorporates inductive clamp circuitry to the basic class E amplifier circuit. Class E amplifiers with this topology can be used in plasma applications where the load conditions are dynamic.

Abdullah Eroglu; Dan Lincoln

2005-01-01

40

New topology for Class E amplifiers  

Microsoft Academic Search

A Class E RF amplifier, which can operate into any load conditions without need for other additional circuitry to protect transistors, is introduced. This is provided by the new topology, which is called an inductive clamp. Our topology incorporates inductive clamp circuitry to the basic Class E amplifier circuit and it has all the benefits of Class E amplifiers. Additionally,

A. Eroglu; D. Lincoln; A. Radomski; Y. Chawla

2007-01-01

41

A Neutron-Hardened Intermediate-Frequency Amplifier.  

National Technical Information Service (NTIS)

An IF amplifier capable of surviving in a neutron environment has been designed and evaluated. The design described uses readily available silicon NPN epitaxial planar transistors throughout. The amplifier includes an automatic gain control and video dete...

J. M. Barnes

1968-01-01

42

High Frequency Low Noise Amplifier Project.  

National Technical Information Service (NTIS)

The design of low noise high frequency amplifiers using S parameters for transistors is described. Simple equations are given for the design of the matching circuits and for determining the minimum noise figure parameters.

W. J. Fleming

1981-01-01

43

Hybrid integrated lumped-element microwave amplifiers  

Microsoft Academic Search

This paper describes the development of microwave lumped-element thin-film amplifiers. The basic design philosophy underlying lumped inductors and capacitors at microwave frequencies is reviewed, showing how Q's of 100 are achieved. A variety of tunable input, output, and interstage integrated lumped-element networks for transistor amplifiers were fabricated. The gain and efficiency of 2-GHz class-C operated transistors mounted in these circuits

MARTIN CAULTON; STANLEY P. KNIGHT; DANIEL A. DALY

1968-01-01

44

A fast, thermally stable bipolar pulse amplifier  

Microsoft Academic Search

An alternative to the normal 'audio'-type pulse amplifier which provides high-power electrical pulses with fast rise and fall times is described. The amplifier uses saturated transistors without feedback. The basic concept is to provide separate drives to the complementary output transistors with a mechanism to ensure that there can be no common-mode current: that even with device delay times it

R. N. Caffin

1982-01-01

45

A transimpedance amplifier using a novel current mode feedback loop  

Microsoft Academic Search

We present a transimpedance amplifier stage based on a novel current mode feedback topology. This circuit employs exclusively NMOS and PMOS transistors and requires no capacitor to stabilize the transimpedance loop and no resistor for the transresistance feedback and transistor loading. This amplifier circuit is fully compatible with submicron digital CMOS processes. The active feedback network consists of two grounded

Pierre Jarron; Francis Anghinolfi; Eric Delagne; Wladek Dabrowski; Luitwin Scharfetter

1996-01-01

46

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

47

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

48

A micropower electrocardiogram amplifier.  

PubMed

We introduce an electrocardiogram (EKG) preamplifier with a power consumption of 2.8 muW, 8.1 muVrms input-referred noise, and a common-mode rejection ratio of 90 dB. Compared to previously reported work, this amplifier represents a significant reduction in power with little compromise in signal quality. The improvement in performance may be attributed to many optimizations throughout the design including the use of subthreshold transistor operation to improve noise efficiency, gain-setting capacitors versus resistors, half-rail operation wherever possible, optimal power allocations among amplifier blocks, and the sizing of devices to improve matching and reduce noise. We envision that the micropower amplifier can be used as part of a wireless EKG monitoring system powered by rectified radio-frequency energy or other forms of energy harvesting like body vibration and body heat. PMID:23853270

Fay, L; Misra, V; Sarpeshkar, R

2009-10-01

49

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

50

Series-Tuned Amplifier, a Low Noise Preamplifier  

Microsoft Academic Search

Parallel-tuned circuits are commonly used in transistor bandpass amplifiers, e.g., IF amplifiers. However, series-tuned circuits have some important advantages. This correspondence presents a simple noise analysis for a parallel-tuned and a series-tuned amplifier. The transfer functions of both amplifiers are similar, but the series-tuned amplifier gives a smaller noise figure. Hence, series-tuned circuits are especially advantageous in preamplifiers.

O. Suominen

1967-01-01

51

Development of 2 W UHF power amplifier  

Microsoft Academic Search

This paper describes the development of a three-stage transistor amplifier delivering a power output of 2 W in the frequency range 720 MHz-820 MHz. The input and output matching networks of the amplifier are realized on microstrips. Design of a power stage is discussed in detail. The amplifier meets all the design goals e.g., 2 W power output, bandwidth, ease

D. Rustogi; V. K. Garg; R. V. Singh

1977-01-01

52

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

ERIC Educational Resources Information Center

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

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

53

Switching Transistor  

NASA Astrophysics Data System (ADS)

Westinghouse Electric Corporation's D60T transistors are used primarily as switching devices for controlling high power in electrical circuits. It enables reduction in the number and size of circuit components and promotes more efficient use of energy. Wide range of application from a popcorn popper to a radio frequency generator for solar cell production.

1981-01-01

54

PULSE AMPLIFIER  

DOEpatents

The improvement of pulse amplifiers used with scintillation detectors is described. The pulse amplifier circuit has the advantage of reducing the harmful effects of overloading cause by large signal inputs. In general the pulse amplifier circuit comprises two amplifier tubes with the input pulses applied to one amplifier grid and coupled to the second amplifier tube through a common cathode load. The output of the second amplifier is coupled from the plate circuit to a cathode follower tube grid and a diode tube in connected from grid to cathode of the cathode follower tube. Degenerative feedback is provided in the second amplifier by coupling a signal from the cathode follower cathode to the second amplifier grid. The circuit proqides moderate gain stability, and overload protection for subsequent pulse circuits.

Johnstone, C.W.

1958-06-17

55

Use of thermal feedback to produce 20 cps. low frequency rolloff in a microelectronic video amplifier  

Microsoft Academic Search

The low-frequency response attainable in semiconductor network ac amplifiers is limited by the large physical size required for coupling components. Better low-frequency response can be achieved with field effect amplifiers than with transistor amplifiers, but at the expense of reduced bandwidth. Hence, direct-coupled transistor stages are commonly used in semiconductor network video amplifiers when high cutoff frequencies are required. A

J. D. Merryman; S. P. Emmons

1964-01-01

56

Laser Amplifier.  

National Technical Information Service (NTIS)

An invention is presented relating to a laser amplifier and, more particularly, to chambers for the containment and energization of an amplifying medium. In a preferred embodiment of the invention, an apparatus is provided for laser amplification with hig...

1978-01-01

57

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

58

Transistors Assessment  

NSDL National Science Digital Library

This brief assessment on transistors is intended to be used after students have completed the introductory activity on the topic, which may be located here. The assessment consists of 11 multiple choice and short answer questions. The other educational modules in this series can be found here. Instructors and students are encouraged to sign up with the Electron Technologies site here before starting to use these materials.

2012-10-08

59

A millimeter-wave monolithic grid amplifier  

SciTech Connect

A 36-element monolithic grid amplifier has been fabricated. The peak gain is 5 dB at 40.8 GHz with a 3-dB bandwidth of 1.4 GHz. The active elements are pairs of heterojunction-bipolar-transistor`s(HBT`s). The individual transistors in the grid have a maximum oscillation frequency, f{sub max}, of 100 GHz. The grid includes base stabilizing capacitors which result in a highly stable grid. This is the first report of a successful monolithic grid amplifier.

Liu, C.M.; Rutledge, D.B. [California Institute of Technology, Pasadena, CA (United States); Sovero, E.A. [Rockwell International Corporation, Thousand Oaks, CA (United States)] [and others

1995-11-01

60

Gallium nitride based transistors  

NASA Astrophysics Data System (ADS)

An overview is presented of progress in GaN electronic devices along with recent results from work at UCSB. From 1995 to 2001, the power performance of AlGaN/GaN high electron mobility transistors (HEMT) improved from 1.1 to 11 W mm-1, respectively. The disadvantage of the low thermal conductivity of the sapphire substrate was mitigated by flip-chip bonding onto AlN substrates, yielding large periphery devices with an output power of 7.6 W. A variety of HEMT amplifier circuits have been demonstrated. The first AlGaN/GaN heterojunction bipolar transistor (HBT) was demonstrated in 1998, with a current gain of about 3. By developing the technique of emitter regrowth, a current gain of 10 was achieved in both GaN BJTs and AlGaN/GaN HBTs. A common emitter current gain cutoff frequency of 2 GHz was measured. Critical issues involved in the growth of high quality AlGaN/(AlN)/GaN heterostructures and GaN:Mg by metal-organic chemical vapour deposition (MOCVD) and molecular beam epitaxy (MBE) and the device fabrication are discussed.

Xing, H.; Keller, S.; Wu, Y.-F.; McCarthy, L.; Smorchkova, I. P.; Buttari, D.; Coffie, R.; Green, D. S.; Parish, G.; Heikman, S.; Shen, L.; Zhang, N.; Xu, J. J.; Keller, B. P.; Den Baars, S. P.; Mishra, U. K.

2001-08-01

61

Robust Sense Amplifier Design under Random Dopant Fluctuations in Nano-Scale CMOS Technologies  

Microsoft Academic Search

Variation in transistor characteristics and particularly threshold voltage (Vt) has emerged as a major challenge for circuit design in scaled technologies. Process variations result in increased mismatch among neighboring transistors which can affect the correct functionality of circuits such as sense amplifiers. In this paper, we will analyze the impact of process variations on sense amplifier circuits in detail. We

Joyce Yeung; Hamid Mahmoodi

2006-01-01

62

Robust Sense Amplifier Design under Random Dopant Fluctuations in Nano-Scale CMOS Technologies  

Microsoft Academic Search

Variation in transistor characteristics and particularly threshold voltage (Vt) has emerged as a major challenge for circuit design in scaled technologies. Process variations result in increased mismatch among neighboring transistors which can affect the correct functionality of circuits such as sense amplifiers. In this paper, we will analyze the impact of process variations on sense amplifier circuits in detail. We

Joyce Yeung; Hamid Mahmoodi

2008-01-01

63

LOGARITHMIC AMPLIFIER  

DOEpatents

A logarithmic current amplifier circuit having a high sensitivity and fast response is described. The inventor discovered the time constant of the input circuit of a system utilizing a feedback amplifier, ionization chamber, and a diode, is inversely proportional to the input current, and that the amplifier becomes unstable in amplifying signals in the upper frequency range when the amplifier's forward gain time constant equals the input circuit time constant. The described device incorporates impedance networks having low frequency response characteristic at various points in the circuit to change the forward gain of the amplifler at a rate of 0.7 of the gain magnitude for every two times increased in frequency. As a result of this improvement, the time constant of the input circuit is greatly reduced at high frequencies, and the amplifier response is increased.

De Shong, J.A. Jr.

1957-12-31

64

GaInP\\/GaAs collector-up tunneling-collector heterojunction bipolar transistors (Cup TC-HBTs): optimization of fabrication process and epitaxial layer structure for high-efficiency high-power amplifiers  

Microsoft Academic Search

This paper describes a novel heterojunction bipolar transistor (HBT) structure, the collector-up tunneling-collector HBT (C-up TC-HBT), that minimizes the offset voltage VCE,sat and the knee voltage Vk. In this device, a thin GaInP layer is used as a tunnel barrier at the base-collector (BC) junction to suppress hole injection into the collector, which results in small VCE,sat. Collector-up configuration is

Kazuhiro Mochizuki; Rebecca J. Welty; Peter M. Asbeck; Charles R. Lutz; Roger E. Welser; Susan J. Whitney; Noren Pan

2000-01-01

65

X-Band Peeled HEMT Amplifier.  

National Technical Information Service (NTIS)

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 th...

P. G. Young R. R. Romanofsky S. A. Alterovitz E. D. Smith

1993-01-01

66

Transistor Design Considerations for Low-Noise Preamplifiers  

Microsoft Academic Search

A review is presented of design considerations for GaAs Schottky-barrier FETs and other types of transistors in low-noise amplifiers for capacitive sources which are used in nuclear radiation detectors and high speed fiber-optic communication systems. Ultimate limits on performance are evaluated in terms of the gm\\/Ci ratio and the gate leakage current to minimize the noise sources. Si bipolar transistors

R. B. Fair

1976-01-01

67

12 W monolithic X-band HBT power amplifier  

Microsoft Academic Search

Monolithic, two-stage X-band power amplifiers were designed and fabricated using AlGaAs\\/GaAs heterojunction bipolar transistors (HBTs). Output power levels of up to 12.5 W continuous wave (CW) were demonstrated at 9.2 GHz from single-chip HBT amplifiers measuring 3.8 mm×4.7 mm in size. Two amplifier designs were fabricated using optimized 300-?m common-emitter unit cells. Device and circuit design aspects of this work

M. A. Khatibzadeh; B. Bayraktarogluf; T. Kim

1992-01-01

68

Note: A high dynamic range, linear response transimpedance amplifier  

NASA Astrophysics Data System (ADS)

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 109?, 3 × 107?, and 104? with a bandwidth of 100 Hz.

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

2012-02-01

69

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

70

Developments in Transistor Electronics†  

Microsoft Academic Search

The design theory of point-contact and junction transistors is reviewed in this paper. Selected examples illustrate the small-signal and large-signal properties of junction transistors. These phenomena are related to the theory of p— n junctions. Also, it is indicated how circuit engineers benefit from a certain know-ledge of transistor theory.

L. B. Valdes

1958-01-01

71

Characterization of broadband Monolithic Gallium Nitride distributed power amplifier using thermal imaging technique  

Microsoft Academic Search

A thermal imaging technique is used to characterize a Monolithic Gallium Nitride distributed power amplifier under DC and RF drive conditions. The temperature difference among the active cells (transistors) in distributed power amplifier is observed under RF drive conditions. It is believed that this non-uniform performance of individual cells in broadband distributed power amplifier results in its lower efficiency and

Chenggang Xie; Cedar Rapids

2011-01-01

72

An alternative process for solid state power amplifiers using large S parameters  

Microsoft Academic Search

A new method related to power amplifier design is described in this paper. Whereas linear amplifiers require only resolving the double matching problem, designing power amplifiers leads to setting up an accurate method allowing achievement of optimum performance from the transistors. Based on large signal S parameters, defined as function of the input power and of the frequency, this approach

M. Hazouard; E. Kerherve; P. Jarry

2000-01-01

73

11.1: Development of vacuum transistor using hafnium nitride field emitter array  

Microsoft Academic Search

We fabricated gated 40,000-tip HfN-FEAs and evaluated HfN-FEA as an active device. The vacuum transistor has triode structure of a gated HfN-FEA and collector electrode. This vacuum transistor has collector current of 1.1 mA, transconductance of 0.27 mS, collector resistance of 2.8 M? and voltage amplification factor of 750 when applying emitter voltage of 58 V. This vacuum transistor amplified

K. Ikeda; W. Ohue; K. Endo; Y. Gotoh; H. Tsuji

2010-01-01

74

Susceptibility of UHF RF Transistors to High Power UHF Signals - Part II.  

National Technical Information Service (NTIS)

This report describes Part II of a program initiated to determine what effects high power UHF/microwave signals have upon solid state components, such as transistors used in RF amplifier stages of high power receivers. The electromagnetic vulnerability (E...

H. J. Hewitt R. A. Blore J. J. Whalen

1976-01-01

75

LOGARITHMIC AMPLIFIER  

DOEpatents

Electronic,amplifier circuits, especially a logai-ithmic amplifier characterizxed by its greatly improved strability are discussed. According to the in ention, means are provided to feed bach the output valtagee to a diode in the amplifier input circuit, the diode being utilized to produce the logarithmic characteristics. The diode is tics, The diode isition therewith and having its filament operated from thc same source s the filament of the logarithmic diode. A bias current of relatively large value compareii with the signal current is continuously passed through the compiting dioie to render the diode insensitivy to variations in the signal current. by this odes kdu to variaelled, so that the stability of the amlifier will be unimpaired.

Wade, E.J.; Stone, R.S.

1959-03-10

76

An All-Transistor 1KW High-Gain UHF Power Amplilier (Correspondence)  

Microsoft Academic Search

A power amplifier in which the outputs of 64 RCA type 2N5016 overlay transistors are combined to provide a total CW output power of 1 kW at 400 MHz is described. A concept is employed wherein several transistors are connected in parallel to first form a power module, and then the outputs of a number of modules are combined in

R. L. Bailey; W. P. Bennett; L. F. Heckman; I. E. Martin

1969-01-01

77

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

78

High Frequency Low Noise Amplifier Project Projeto de Amplificadores de Baixo Ruido Em Alta Frequencia.  

National Technical Information Service (NTIS)

The design of low noise high frequency amplifiers using S parameters for transistors is described. Simple equations are given for the design of the matching circuits and for determining the minimum noise figure parameters.

W. J. Fleming

1981-01-01

79

Operational Amplifiers  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Operational Amplifiers, is the eighth chapter in Volume III âÂÂSemiconductors. A few of the topics covered in this chapter include: The "operational" amplifier; Negative feedback; Voltage-to-current signal conversion; and Differentiator and integrator circuits. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-14

80

Chicago Amplified  

NSDL National Science Digital Library

From the Chicago Public Library to the Lyric Opera, the Chicago Amplified program based at Chicago Public Radio brings the best and the brightest from the Chicago region to anyone with an Internet connection. The program was started in 2006, and visitors can browse past programs all the way back to that year. Clicking on each program will allow users to read a description of the show's content and listen to audio online.

81

Teaching the common emitter amplifier  

NASA Astrophysics Data System (ADS)

If one wishes to teach some device electronics in schools it will have to be very limited. It is not productive to measure all the common emitter and common base characteristics of the bipolar transistor as required by at least one A-level syllabus. To do so wastes pupil time and leads to considerable confusion. Nor should the study be extended to cover for example all possible methods of biasing a common emitter amplifier. What is needed is a 'bare bones' approach, enough to give a first step towards understanding the subject. A case can be made for the study of an operational amplifier in electronic circuits, treating it as an ideal electronic 'device'. However, the author's personal feeling is that the study of a single active device such as the bipolar transistor provides a firm background from which students can extend their study of electronics and has the advantage in a physics course that from there it is a very short step to discuss a simple model for the internal mechanisms of semiconductor devices.

Ellse, Mark D.

1984-11-01

82

Low-distortion CMOS complementary class E RF tuned power amplifiers  

Microsoft Academic Search

A low distortion tuned power amplifier which is suitable for integrated circuit implementation is proposed. The amplifier is a complementary class-E tuned power amplifier because of both P-type and N-type transistors are employed to achieve a highly symmetrical topology, thereby reducing the significant distortion in the output signal of the conventional single-ended class-E power amplifier. In this paper, a complementary

Steve Hung-Lung Tu; Chris Toumazou

2000-01-01

83

GaAs HBT MMIC broadband amplifiers from DC to 20 GHz  

Microsoft Academic Search

Three monolithic wideband and high-gain amplifiers implemented with 2-3-?m GaAs heterojunction bipolar transistor (HBT) monolithic microwave IC (MMIC) technology are presented. A single-stage direct-coupled amplifier achieves a 3-dB bandwidth from DC to 20 GHz, which is believed to be the widest bandwidth reported for direct-coupled amplifiers. The amplifier has a 6-dB nominal gain with a peak gain of 7.3 dB

K. W. Kobayashi; D. K. Umemoto; R. Esfandiari; A. K. Oki; L. M. Pawlowicz; M. E. Hafizi; L. Tran; J. B. Camou; K. S. Stolt; D. C. Streit; M. E. Kim

1990-01-01

84

A 100-element HBT grid amplifier  

Microsoft Academic Search

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

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

1993-01-01

85

Susceptibility of UHF RF Transistors to High Power UHF Signals.  

National Technical Information Service (NTIS)

The report describes a program that was initiated to determine what effects high power UHF/microwave signals have upon solid state components such as transistors used in RF amplifier stages of UHF/microwave receivers. The effects of CW power at 200 MHz up...

H. J. Hewitt J. J. Whalen

1974-01-01

86

A Flush Toilet Model for the Transistor  

NASA Astrophysics Data System (ADS)

In introductory physics textbooks, diodes working principles are usually well described in a relatively simple manner. According to our experience, they are well understood by students. Even when no formal derivation of the physics laws governing the current flow through a diode is given, the use of this device as a check valve is easily accepted. This is not true for transistors. In most textbooks the behavior of a transistor is given without formal explanation. When the amplification is computed, for some reason, students have difficulties in identifying the basic physical mechanisms that give rise to such an effect. In this paper we give a simple and captivating illustration of the working principles of a transistor as an amplifier, tailored to high school students even with almost no background in electronics nor in modern physics. We assume that the target audience is familiar with the idea that a diode works as a check valve for currents. The lecture emphasis is on the illustration of physics principles governing the behavior of a transistor, rather than on a formal description of the processes leading to amplification.

Organtini, Giovanni

2012-04-01

87

Precision absolute value amplifier for a precision voltmeter  

DOEpatents

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

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

1985-01-01

88

Precision absolute-value amplifier for a precision voltmeter  

DOEpatents

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

Hearn, W.E.; Rondeau, D.J.

1982-10-19

89

Quantum interference in transistors  

Microsoft Academic Search

We consider adiabatic charge transport through transistor based on quantum dot caused by two periodically changing external perturbations. Both the magnitude and the sign of the transmitted charge are extremely sensitive to the configuration of the transistor and to the magnetic field. We find the correlation function characterizing the random value of this pumped charge for arbitrary strength of perturbation.

Timur A. Shutenko; Igor L. Aleiner; Boris L. Altshuler

2008-01-01

90

TRANSISTORIZED RADIATION MONITORS  

Microsoft Academic Search

Paper presented at I.R.E. Professional Group on Nuclear Science ; Meeting, New York, Oct. 3l, l957. The advantages of transistors over vacuum ; tubes in radiation instruments have long been realized but a somewhat different ; approach to circuit design must be followed in developing transistor instruments, ; as compared with that used in vacuum tube circuits, and this seems

Goulding

1957-01-01

91

Transistorized Radiation Monitors  

Microsoft Academic Search

The advantages of transistors over vacuum tubes in radiation instruments have long been realized but a somewhat different approach to circuit design must be followed in developing transistor instruments, as compared with that used in vacuum tube circuits, and this seems to have discouraged many from developing such circuits. The purpose of this paper is to describe in some detail

F. S. Goulding

1958-01-01

92

Single transistor latch phenomenon in junctionless transistors  

NASA Astrophysics Data System (ADS)

In this work, we report on the single transistor latch phenomenon in junctionless transistors. In the latch condition, the device is unable to turn-off despite a reduction in gate bias. It is shown that impact ionization induced latch condition can occur due to an increase in drain bias, silicon film thickness, gate oxide thickness, and doping concentration. The latch phenomenon is explained in terms of generation-recombination rates, electrostatic potential, electric field distribution and product of current density and electric field (J.E). As latch condition is undesirable for dynamic memory applications, the work highlights the significance of (J.E) as a performance metric to avoid the junctionless transistor being driven into the latch mode.

Singh Parihar, Mukta; Ghosh, Dipankar; Kranti, Abhinav

2013-05-01

93

A high-efficiency HBT MMIC power amplifier  

Microsoft Academic Search

An AlGaAs\\/GaAs heterojunction bipolar transistor monolithic microwave IC (HBT MMIC) power amplifier is developed that demonstrates very high power-added efficiency, high gain, and broad bandwidth. It uses a cascode structure with four 200-?m common-emitter HBT cells driving four common-base cells of the same size. This amplifier achieves over 14-dB gain from 6 to 10 GHz, with a peak power-added efficiency

R. Ramachandran; M. Nijjar; A. Podell; E. Stonehatn; S. Mitchell; N. L. Wang; W. J. Ho; M. F. Chang; G. J. Sullivan; J. A. Higgins; P. M. Asbeck

1990-01-01

94

Design Method for UHF Class-E Power Amplifiers  

Microsoft Academic Search

This paper describes a method for designing single-ended high-efficiency switched-mode class-E UHF power amplifiers. The design procedure consists of a modified load pull transistor characterization from which a power\\/efficiency metric is calculated. Results for four prototypes using different device technologies are presented in detail. Amplifiers with Si-LDMOS, SiC-MESFET, GaN-HEMT on a Si substrate, and GaN-HEMT on a SiC substrate produce

N. D. Lopez; J. Hoversten; Z. Popovic

2009-01-01

95

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

96

Design of GaAs MMIC transistors for the low-power low noise applications  

Microsoft Academic Search

The paper investigates the problem of minimizing bias power for the low noise GaAs amplifiers. The model of the amplifier parameters versus transistor gate width is presented and used to derive the conditions for noise optimization. It is shown that optimum FETs are rather wide and may operate at very low current densities. Complete amplifier stages with only 3-5 mW

Zbigniew M. Nosal

2000-01-01

97

A nanoscale single-molecule amplifier and its consequences  

Microsoft Academic Search

Our ability to manipulate atoms and molecules on an individual basis has opened a new experimental frontier that makes feasible the quest for single molecular-scale devices as successors to the transistor. Here, we discuss our realization of the first amplifier using a single fullerene molecule less than 1 nm in diameter as the active element. This C60 molecular device works

CHRISTIAN JOACHIM; JAMES KAZIMIERZ GIMZEWSKI

1998-01-01

98

Transmitters using Power Amplifiers  

Microsoft Academic Search

TWT amplifiers have traditionally been used for microwave communications links requiring high power amplifiers. The mean-time-before-failure (MTBF) of traveling wave tube amplifiers (TWTAs) is low compared to solid state power amplifiers and generally limits the communication system performance. The frequency and power capabilities of solid state amplifiers using FETs and IMPATT devices have been advancing rapidly in recent years. Transmitters

J. Goel; S. Yuan

1984-01-01

99

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

100

L Band Low Noise Amplifier Project Projeto de Amplificadores de Baixo Ruido M Banda L.  

National Technical Information Service (NTIS)

The design of L band low noise amplifiers is discussed including the components available the problems encountered in this band. Two balanced amplifiers in 1.7 GHz for the WEFAX conversor are described. The first uses bipolar transistors and the second Ga...

E. A. P. Tude

1983-01-01

101

Input microwave amplifiers from the point of view of EMC requirements  

NASA Astrophysics Data System (ADS)

A systematic account is given of the features of low-noise microwave amplifiers in relation to EMC considerations. The EMC characteristics of various types of amplifiers are examined, including TWT, BWT, transverse-wave parametric, semiconductor parametric, and transistor. The relevant literature is briefly reviewed.

Algazinov, E. K.; Mnoian, V. I.

1985-08-01

102

Spin Hall Effect Transistor  

NASA Astrophysics Data System (ADS)

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our study shows the utility of the spin Hall effect in a microelectronic device geometry, realizes the spin transistor with electrical detection directly along the gated semiconductor channel, and provides an experimental tool for exploring spin Hall and spin precession phenomena in an electrically tunable semiconductor layer.

Wunderlich, Jörg; Park, Byong-Guk; Irvine, Andrew C.; Zârbo, Liviu P.; Rozkotová, Eva; Nemec, Petr; Novák, Vít; Sinova, Jairo; Jungwirth, Tomás

2010-12-01

103

Spin Hall effect transistor.  

PubMed

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our study shows the utility of the spin Hall effect in a microelectronic device geometry, realizes the spin transistor with electrical detection directly along the gated semiconductor channel, and provides an experimental tool for exploring spin Hall and spin precession phenomena in an electrically tunable semiconductor layer. PMID:21205664

Wunderlich, Jörg; Park, Byong-Guk; Irvine, Andrew C; Zârbo, Liviu P; Rozkotová, Eva; Nemec, Petr; Novák, Vít; Sinova, Jairo; Jungwirth, Tomás

2010-12-24

104

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

105

Spin Hall Effect Transistor  

Microsoft Academic Search

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the

Jörg Wunderlich; Byong-Guk Park; Andrew C. Irvine; Liviu P. Zârbo; Eva Rozkotová; Petr Nemec; Vít Novák; Jairo Sinova; Tomás Jungwirth

2010-01-01

106

Compton Versterker (Compton Amplifier).  

National Technical Information Service (NTIS)

The broad wave amplifier was developed to amplify signals from Compton detectors, which are part of the security system for the MEA (Medium Energy Accelerator) linear amplifier in Amsterdam. Compton detectors determine the position of the electrons in the...

J. T. van Es J. C. Verkooijen

1989-01-01

107

Switchable auto gain amplifier  

DOEpatents

This invention is comprised of a switchable auto gain amplifier system for amplifying electrical signals of unknown magnitude has a plurality of amplifiers having different gains, each amplifier having an input connected to a system input. A switch controllably directs only one of the amplifier outputs to a system output. The switch is controlled by comparators providing an electrical outputs indicating each saturated amplifier. 2 figs.

Boye, C.A.; Phipps, G.S.; Schaefer, J.P.

1988-10-21

108

An Ultra-Low-Voltage Ultra-Low-Power Weak Inversion Composite MOS Transistor: Concept and Applications  

NASA Astrophysics Data System (ADS)

This work presents an ultra-low-voltage ultra-low-power weak inversion composite MOS transistor. The steady state power consumption and the linear swing signal of the composite transistor are comparable to a single transistor, whereas presenting very high output impedance. This work also presents two interesting applications for the composite transistor; a 1:1 current mirror and an extremely low power temperature sensor, a thermistor. Both implementations are verified in a standard 0.35-?m TSMC CMOS process. The current mirror presents high output impedance, comparable to the cascode configuration, which is highly desirable to improve gain and PSRR of amplifiers circuits, and mirroring relation in current mirrors.

Ferreira, Luis H. C.; Pimenta, Tales C.; Moreno, Robson L.

109

A 6-bit bias-less pipelined ADC with open-loop amplifiers  

Microsoft Academic Search

This paper employs a CMOS 0.18 µm CMOS technology to design a 6-bit 250 MS\\/s pipelined ADC with open- loop amplifiers. The amplifiers utilize MOS transistors in triode region instead of resistors and current sources to decrease the process variation and the need of bias circuits. The amplification managed with the global-gain-control loop which realizes the error amplifier with a

Ding-Lan Shen; Yi-Ming Tsai

2011-01-01

110

High-linearity, low DC power monolithic GaAs HBT broadband amplifiers to 11 GHz  

Microsoft Academic Search

Two broadband monolithic amplifiers based on GaAs heterojunction bipolar transistors (HBT) have been developed covering the 0.05-11-GHz frequency band. The hybrid designs reported by B.L. Nelson et al. (1989 IEEE GaAs IC Symp. Digest, Oct. 1989, p.79-82) have been successfully implemented with monolithic microwave IC (MMIC) technology. These amplifiers are the first reported balanced and distributed MMIC HBT amplifiers and

B. L. Nelson; D. K. Umemoto; C. B. Perry; R. Dixit; B. R. Allen; M. E. Kim; A. K. Oki

1990-01-01

111

GaAs Device Reliability: High Electron Mobility Transistors and Heterojunction Bipolar Transistors  

NASA Astrophysics Data System (ADS)

The two main GaAs-based electronic device technologies are high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs). Both technologies are commercialized for use in low-noise amplifiers, radar, and fiber optic data transmission systems. In this chapter, we will summarize the degradation mechanisms that limit the lifetime of these devices. A variety of contact and surface degradation mechanisms have been reported but differ in the two device technologies - for HEMTs, the layers are thin and relatively lightly doped compared to HBT structures, and there is a metal Schottky gate that is directly on the semiconductor. By contrast, the HBT relies on pn junctions for current modulation and has only ohmic contacts. This leads to different degradation mechanisms for the two types of devices.

Ren, F.; Douglas, E. A.; Pearton, Stephen J.

112

Development on the high-speed bipolar transistor with BF\\/sub 2\\/-implanted thin base  

Microsoft Academic Search

The polysilicon emitter bipolar process technology in which BF2-implanted base layer and rapid thermal anneal (RTA) are used has been reported. The process and device have been simulated by TSUPREM4 and MEDICI software respectively. High-speed NPN Transistor with beta of 160, fT of 9.5GHz and BVCEO of 6.0V has been achieved. Based on the NPN transistor, broad-band amplifier with bandwidth

Yang Qiudong; Li Rongqiang; Tan Kaizhou; Zhang Jing; Zhong Yi; He Kaiquan; LiuYukui

2006-01-01

113

Design of High-Performance Analog Circuits Using Wideband gm-Enhanced MOS Composite Transistors  

Microsoft Academic Search

In this paper, we present a new composite transistor circuit design technique that provides superior performance enhancement to analog circuits. By adding a composite transistor to the cascode-compensated amplifier, it has achieved a 102dB DC gain, and a 37.6MHz unity gain bandwidth while driving a 2nF heavy capacitive load at a single 1.8V supply. In the comparison of power-bandwidth and

Yang Tian; Pak Kwong Chan

2010-01-01

114

Monolithically integrated bacteriorhodopsin-GaAs field-effect transistor photoreceiver  

NASA Astrophysics Data System (ADS)

We have applied the large photovoltage developed across a layer of selectively deposited bacteriorhodopsin to the gate terminal of a monolithically integrated GaAs-based modulation-doped field-effect transistor, which delivers an amplified photoinduced current signal. The integrated biophotoreceiver device exhibits a responsivity of 3.8 A/W. The optoelectronic integrated circuit is achieved by molecular-beam epitaxy of the field-effect transistor's heterostructure, photolithography, and selective-area bacteriorhodopsin electrodeposition.

Bhattacharya, Pallab; Xu, Jian; Varo, Gyorgy; Marcy, Duane L.; Birge, Robert R.

2002-05-01

115

A new simplified high radio frequency power amplifier  

SciTech Connect

In order to simplify a present standard high rf power amplifier of ion cyclotron range of frequency plasma heating system, a new amplifier arrangement composed of a tetrode with a grounded cathode and a field effect transistor (FET) switching circuit providing an input rf power is proposed. The FET switching circuit is so small that it can be installed close to the tetrode in one cubicle. It might be called a single tube high rf power amplifier. A test amplifier composed of the tetrode (8F76R) and the FET (2SK-1310) switching circuit is constructed. The maximum output rf power of 8.5 kW was stably obtained at 70 MHz. The feasibility of the single tube high rf power amplifier was experimentally proved.

Ogawa, Y.; Okutsu, H.; Kobayashi, N.; Hayakawa, A. [Advanced System Design and Engineering Department, Toshiba Corporation, Shinsugita-cho 8, Isogo-ku, Yokohama-shi 235-8523 (Japan)

2004-10-01

116

SQUARE WAVE AMPLIFIER  

DOEpatents

An amplifier circuit is described for amplifying sigmals having an alternating current component superimposed upon a direct current component, without loss of any segnnent of the alternating current component. The general circuit arrangement includes a vibrator, two square wave amplifiers, and recombination means. The amplifier input is connected to the vibrating element of the vibrator and is thereby alternately applied to the input of each square wave amplifier. The detailed circuitry of the recombination means constitutes the novelty of the annplifier and consists of a separate, dual triode amplifier coupled to the output of each square wave amplifier with a recombination connection from the plate of one amplifier section to a grid of one section of the other amplifier. The recombination circuit has provisions for correcting distortion caused by overlapping of the two square wave voltages from the square wave amplifiers.

Leavitt, M.A.; Lutz, I.C.

1958-08-01

117

The resonant body transistor.  

PubMed

This paper introduces the resonant body transistor (RBT), a silicon-based dielectrically transduced nanoelectromechanical (NEM) resonator embedding a sense transistor directly into the resonator body. Combining the benefits of FET sensing with the frequency scaling capabilities and high quality factors (Q) of internal dielectrically transduced bar resonators, the resonant body transistor achieves >10 GHz frequencies and can be integrated into a standard CMOS process for on-chip clock generation, high-Q microwave circuits, fundamental quantum-state preparation and observation, and high-sensitivity measurements. An 11.7 GHz bulk-mode RBT is demonstrated with a quality factor Q of 1830, marking the highest frequency acoustic resonance measured to date on a silicon wafer. PMID:20180594

Weinstein, Dana; Bhave, Sunil A

2010-04-14

118

Segmented amplifier configurations for laser amplifier  

DOEpatents

An amplifier system for high power lasers, the system comprising a compact array of segments which (1) preserves high, large signal gain with improved pumping efficiency and (2) allows the total amplifier length to be shortened by as much as one order of magnitude. The system uses a three dimensional array of segments, with the plane of each segment being oriented at substantially the amplifier medium Brewster angle relative to the incident laser beam and with one or more linear arrays of flashlamps positioned between adjacent rows of amplifier segments, with the plane of the linear array of flashlamps being substantially parallel to the beam propagation direction.

Hagen, Wilhelm F. (Livermore, CA)

1979-01-01

119

35 GHz pseudomorphic HEMT MMIC power amplifier  

Microsoft Academic Search

0.25 ?m-gate-length double-heterojunction InGaAs pseudomorphic HEMTs (high-electron-mobility transistors) have been integrated into a three-stage power amplifier MMIC (monolithic microwave integrated circuit) designed for the 34-36 GHz band. This first pass design exhibited a peak small-signal gain of 30 dB, a minimum output power of 200 mW with 20-dB associated gain, a power-added efficiency of greater than 18%, and a return

D. W. Ferguson; S. A. Allen; M. Y. Kao; P. M. Smith; P. C. Chao; M. A. G. Upton; J. M. Ballingall

1991-01-01

120

Intrinsic noise characteristics of gallium nitride high electron mobility transistors  

Microsoft Academic Search

Wide bandgap gallium nitride high electron mobility transistors (GaN HEMTs) have recently been developed for microwave sources and amplifiers. An experimental and numerical modeling effort is presented to study noise mechanisms within GaN HEMTs. This allows an equivalent-circuit model to be established, facilitating the extraction of intrinsic noise and also microwave circuit design. ^ Intrinsic noise sources in GaN HEMTs

Sungjae Lee

2004-01-01

121

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

122

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

123

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

124

Design of SiGe HBT UWB low noise amplifier employing broadband noise canceling  

Microsoft Academic Search

A SiGe HBT low-noise amplifier (LNA) for UWB application is presented. According to the analysis for noise of common base transistor, noise canceling structure for SiGe HBT is proposed to reduce the noise arising from common transistor, thus reduce the noise of LNA. Meanwhile it also compensate the gain of the LNA, thus improves the gain flatness. The chip layout

Chunbao Ding; Wanrong Zhang; Hongyun Xie; Liang Chen; Pei Shen; Donghui Zhang; Boyu Liu; Yongqiang Zhou; Zhengjie Guo; Zhiyi Lu

2011-01-01

125

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

126

Transistorized Digital Potentiometer.  

National Technical Information Service (NTIS)

An automatic transistorized digital potentiometer used for input to a digital computer is described. The potentiometer is used in a copper smelting plant to control slow time-varying processes and consists of three basic circuit blocks: a null, a divider,...

K. A. Netrebenko V. B. Reutov

1968-01-01

127

Photoresponsive nanoscale columnar transistors  

PubMed Central

This study reports a general methodology for making stable high-performance photosensitive field effect transistors (FET) from self-assembled columns of polycyclic aromatic hydrocarbons by using single-walled carbon nanotubes (SWNTs) as point contacts. In particular, the molecules used in this work are liquid crystalline materials of tetra(dodecyloxy)hexabenzocoronenes (HBCs) that are able to self-organize into columnar nanostructures with a diameter similar to that of SWNTs and then form nanoscale columnar transistors. To rule out potential artifacts, 2 different structural approaches were used to construct devices. One approach is to coat thin films of HBCs onto the devices with the SWNT–metal junctions protected by hydrogensilsesquioxane resin (HSQ), and the other is to place a droplet of HBC exactly on the nanogaps of SWNT electrodes. Both types of devices showed typical FET behaviors, indicating that SWNT–molecule–SWNT nanojunctions are responsible for the electrical characteristics of the devices. After thermally annealing the devices, HBC molecules assembled into columnar structures and formed more efficacious transistors with increased current modulation and higher gate efficiency. More interestingly, when the devices were exposed to visible light, photocurrents with an on/off ratio of >3 orders of magnitude were observed. This study demonstrates that stimuli-responsive nanoscale transistors have the potential applications in ultrasensitive devices for environmental sensing and solar energy harvesting.

Guo, Xuefeng; Xiao, Shengxiong; Myers, Matthew; Miao, Qian; Steigerwald, Michael L.; Nuckolls, Colin

2009-01-01

128

A high-speed low-noise transimpedance amplifier in a 0.25 ?m CMOS technology  

Microsoft Academic Search

We present the simulated and measured performance of a transimpedance amplifier designed in a quarter micron CMOS process. Containing only NMOS and PMOS devices, this amplifier can be integrated in any submicron CMOS process. The main feature of this design is the use of a transistor in the feedback path instead of a resistor. The circuit has been optimized for

Giovanni Anelli; Kurt Borer; Luca Casagrande; Matthieu Despeisse; Pierre Jarron; Nicolas Pelloux; Shahyar Saramad

2003-01-01

129

Portable musical instrument amplifier  

SciTech Connect

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

130

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

131

Nanosecond Spectrometric Amplifier.  

National Technical Information Service (NTIS)

Nanosecond amplifier intended for operation together with spectrometric amplifiers under conditions of high and changing-in-time loads is described. Zero drift at the amplifier output is <= 200 mu V/C exp 0 . Output pulse rise time equals 3 ns at 25 Ohm l...

G. B. Dzyubenko

1981-01-01

132

A 74GHz bandwidth InAlAs\\/InGaAs-InP HBT distributed amplifier with 13dB gain  

Microsoft Academic Search

To date, distributed amplifiers based on heterojunction bipolar transistors (HBTs) have consistently shown lower gain-bandwidth products than their high electron mobility transistor (HEMT) counterparts. By using improved design techniques, we report a single-stage distributed amplifier with 13-dB gain and 74 GHz 3-dB bandwidth, based on InAlAs\\/InGaAs-InP HBTs with 160-GHz fT and 140-GHz fmax. The high gain and bandwidth results in

Y. Baeyens; R. Pullela; J. P. Mattia; H.-S. Tsai; Y.-K. Chen

1999-01-01

133

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

134

A gallium-nitride push-pull microwave power amplifier  

Microsoft Academic Search

A highly efficient linear, broad-band AlGaN-GaN high electron-mobility transistor (HEMT) push-pull microwave power amplifier has been achieved using discrete devices. Instrumental was a low-loss planar three-coupled-line balun with integrated biasing. Using two 1.5-mm GaN HEMTs, a push-pull amplifier yielded 42% power-added efficiency with 28.5-dBm input power at 5.2 GHz, and a 3-dB bandwidth of 4-8.5 GHz was achieved with class-B

Jong-Wook Lee; Lester F. Eastman; Kevin J. Webb

2003-01-01

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

Exciton optoelectronic transistor.  

PubMed

We demonstrate experimental proof of principle for an optoelectronic transistor based on the modulation of exciton flux via gate voltage. The exciton optoelectronic transistor (EXOT) implements electronic operation on photons by using excitons as intermediate media; the intensity of light emitted at the optical output is proportional to the intensity of light at the optical input and is controlled electronically by the gate. We demonstrate a contrast ratio of 30 between an on state and an off state of the EXOT and its operation at speeds greater than 1 GHz. Our studies also demonstrate high-speed control of both the flux and the potential energy of excitons on a time scale much shorter than the exciton lifetime. PMID:17767273

High, A A; Hammack, A T; Butov, L V; Hanson, M; Gossard, A C

2007-09-01

137

Chemoresponsive monolayer transistors  

PubMed Central

This work details a method to make efficacious field-effect transistors from monolayers of polycyclic aromatic hydrocarbons that are able to sense and respond to their chemical environment. The molecules used in this study are functionalized so that they assemble laterally into columns and attach themselves to the silicon oxide surface of a silicon wafer. To measure the electrical properties of these monolayers, we use ultrasmall point contacts that are separated by only a few nanometers as the source and drain electrodes. These contacts are formed through an oxidative cutting of an individual metallic single-walled carbon nanotube that is held between macroscopic metal leads. The molecules assemble in the gap and form transistors with large current modulation and high gate efficiency. Because these devices are formed from an individual stack of molecules, their electrical properties change significantly when exposed to electron-deficient molecules such as tetracyanoquinodimethane (TCNQ), forming the basis for new types of environmental and molecular sensors.

Guo, Xuefeng; Myers, Matthew; Xiao, Shengxiong; Lefenfeld, Michael; Steiner, Rachel; Tulevski, George S.; Tang, Jinyao; Baumert, Julian; Leibfarth, Frank; Yardley, James T.; Steigerwald, Michael L.; Kim, Philip; Nuckolls, Colin

2006-01-01

138

Broad-band power amplifier using dielectric photonic bandgap structure  

Microsoft Academic Search

Two class AB GaAs field-effect transistor (FET) power amplifiers have been designed and fabricated in the 4.4-4.8 GHz range. In the first case, a dielectric PBG line was incorporated in the design to tune the second harmonic. In the second case, a 50-? line is used with no harmonic tuning. The PBG structure allows broad-band harmonic tuning and is inexpensive

Vesna Radisic; Yongxi Qian; Tatsuo Itoh

1998-01-01

139

Gallium nitride based transistors  

Microsoft Academic Search

An overview is presented of progress in GaN electronic devices along with recent results from work at UCSB. From 1995 to 2001, the power performance of AlGaN\\/GaN high electron mobility transistors (HEMT) improved from 1.1 to 11 W mm-1, respectively. The disadvantage of the low thermal conductivity of the sapphire substrate was mitigated by flip-chip bonding onto AlN substrates, yielding

H. Xing; S. Keller; Y.-F. Wu; L. McCarthy; I. P. Smorchkova; D. Buttari; R. Coffie; D. S. Green; G. Parish; S. Heikman; L. Shen; N. Zhang; J. J. Xu; B. P. Keller; S. P. Den Baars; U. K. Mishra

2001-01-01

140

Bloch Oscillating Transistor as the Null Detector in the Quantum Metrology Triangle  

Microsoft Academic Search

The Bloch oscillating transistor is a new mesoscopic current amplifier with estimated white current noise below 1 fA\\/Hz1\\/2 and potentially low 1\\/f noise. The operation principle and recent results of the BOT are presented and its potential in closing the quantum metrology triangle is analysed

H. Seppia; P. Helisto; J. Hassel; R. Lindell; P. Hakonen

2004-01-01

141

Photonic transistor based on bacteriorhodopsin films  

NASA Astrophysics Data System (ADS)

Light activated optical circuits have several key advantages over conventional electronics because they are free from electrical current losses, resistive heat dissipation, and friction forces that greatly diminish system performance and efficiency. The effects of current leakage and power loss are also crucial design constaints in developing micro-electromechanical (MEMS) technology. An essential device for creating viable micro-optical circuitry is a robust photonic transistor that can act as a small signal switch and amplifier. The proposed photonic transistor is based on the complementary suppression-modulated light transmission properties of thin bacteriorhodopsin (bR) films. The light transmission properties exhibited by the thin film are controlled using the variable wavelength and intensity of the impinging light soruces. The light transmisison properties of the bR film are illustrated using a mathematical model for the two-state photoreaction system. The two-state model represents the longest lifetime in the bR photocycle, largest change in absorption maxima, and high photochemical stability. The optical response is proportional to changes in the light transmission properties of the biometrical, and therefore represents a viable material for creating optoelectronic devices.

Wang, Wei W.; Knopf, George K.; Bassi, Amarjeet S.

2003-10-01

142

Monolithic MESFET distributed baluns based on the distributed amplifier gate-line termination technique  

Microsoft Academic Search

The principles of the distributed amplifier are applied to realize wide-band monolithic distributed baluns. The technique reported here is based on using the gate-line “termination” of a distributed amplifier topology as the noninverting output and the inherent phase inversion property of the metal-semiconductor field-effect transistor (MESFET) to provide the antiphase output from the drain-line. Closed-form expressions are derived for the

Atiqul H. Baree; Ian D. Robertson

1997-01-01

143

A low power fully integrated bandpass operational amplifier for biomedical neural recording applications  

Microsoft Academic Search

This paper presents a low power fully integrated bandpass amplifier for a variety of biomedical neural recording applications. A standard two-stage CMOS amplifier in a closed-loop resistive feedback configuration provides stable AC gain of 39.5 dB at 1 kHz. A PMOS input transistor, biased near the sub-threshold region acting as a high value resistor in the range of hundreds of

Pedram Mohseni; Khalil Najafi

2002-01-01

144

Design of Chopper-Stabilized Amplifiers With Reduced Offset for Sensor Applications  

Microsoft Academic Search

Offset error mechanisms in a single-ended chopper-stabilized amplifier are investigated. The error models and their prediction equations are given. This work also presents a new analytical approach for estimating the switch error in a four-transistor chopping network. A new resistance balancing circuit technique is also introduced, which permits further reduction of DC offsets in conventional chopping operational amplifier (op-amp) or

P. K. Chan; J. Cui

2008-01-01

145

A post-SQUID ac amplifier aimed for multiplexed detector readouts  

Microsoft Academic Search

We have built a room temperature amplifier based on Si JFETs (junction field effect transistors) intended for ac-coupled SQUID (superconducting quantum interference device) readouts, such as in frequency-domain multiplexed transition-edge sensor systems. The amplifier operates at 5 MHz centre frequency where it has the measured noise temperature of 27 K for a 60 Omega load, which includes the noise from

Mikko Kiviranta; Antti Virtanen; Heikki Seppä; Jari Penttilä; Juha Hassel; Panu Helistö

2006-01-01

146

A robust modeling and design approach for dynamically loaded and digitally linearized Doherty amplifiers  

Microsoft Academic Search

In this paper, an active load-pull-based large-signal modeling approach suitable for designing and optimizing Doherty amplifiers is proposed. The optimization of the drive dependant dynamic loads seen by both carrier and peaking amplifier's transistors was carried out using a large-signal load-pull-based behavior model built into CAD software. The latter was also used to optimize the biasing conditions of the peaking

Jérôme Sirois; Slim Boumaiza; Mohamed Helaoui; Gilles Brassard; Fadhel M. Ghannouchi

2005-01-01

147

Reduction of phase noise in linear HBT amplifiers using low-frequency active feedback  

Microsoft Academic Search

In this paper, we investigate the effect of low-frequency active feedback in the 1\\/f phase modulation (PM) noise of a linear SiGe heterojunction bipolar transistor amplifier operating at 1 GHz. The voltage gain and the output resistance of the feedback amplifier were varied and their effect on the baseband collector voltage noise reduction and PM noise reduction were observed. Our

Eva S. Ferre-Pikal

2004-01-01

148

Program to develop an optical transistor and switch  

NASA Astrophysics Data System (ADS)

Previous work has proposed and analyzed the concept of two light beams interacting with a suitable medium to the effect that one beam turns the second beam on or off (an optical switch), or that the modulation in the first beam is amplified in the second (an optical transistor). Switching action was also demonstrated experimentally in uranyl for switching rates up to several kHz. In the present work, a more general survey and analysis was undertaken to identify classes and species of materials for which a particularly effective switching or transistor action can be predicted theoretically. As a class, dense materials, including liquid dyes, have broad absorption band spectra, resulting in low-performance capabilities such as a low transistor gain. In contrast, media in which atomic transitions are free, or shielded, from the fields of other atoms have, as switches and transistors, relatively high speeds of response and low demands on radiation power and mass of interacting materials. As special examples of this class, the performance characteristics of lithium and sodium were calculated and the implications of the results discussed with respect to further action.

Garbuny, M.; Henningsen, T.; Hopkins, R. H.

1985-03-01

149

All-optical excitonic transistor.  

PubMed

We demonstrate experimental proof of principle for all-optical excitonic transistors where light controls light by using excitons as an intermediate medium. The principle of operation of all-optical excitonic transistors is based on the control of exciton fluxes by light. PMID:20479817

Kuznetsova, Y Y; Remeika, M; High, A A; Hammack, A T; Butov, L V; Hanson, M; Gossard, A C

2010-05-15

150

Thermal characterization of power transistors  

Microsoft Academic Search

The idealized concept of thermal resistance as applied to power transistors is discussed. This concept must be used with care because two of the basic assumptions made in applying the concept to these devices are not valid. Contrary to these assumptions, it is shown that 1) the junction temperature of a power transistor is never spatially uniform, and 2) no

FRANK F. OETTINGER; DAVID L. BLACKBURN; S. Rubin

1976-01-01

151

Recent developments in power transistors  

Microsoft Academic Search

Power transistors capable of providing five watts output are now in production. Because these units are relatively non-linear in their characteristics, large signal graphical analysis of their behavior is necessary. To facilitate this, the static characteristics of the grounded base, grounded emitter, and grounded collector circuits are presented for several temperatures. Since power transistors are seldom driven with a high

H. T. Mooers

1955-01-01

152

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

153

Compact laser amplifier system  

DOEpatents

A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

Carr, R.B.

1974-02-26

154

Transparent metal oxide nanowire transistors  

NASA Astrophysics Data System (ADS)

With the features of high mobility, a high electric on/off ratio and excellent transparency, metal oxide nanowires are excellent candidates for transparent thin-film transistors, which is one of the key technologies to realize transparent electronics. This article provides a comprehensive review of the state-of-the-art research activities that focus on transparent metal oxide nanowire transistors. It begins with the brief introduction to the synthetic methods for high quality metal oxide nanowires, and the typical nanowire transfer and printing techniques with emphasis on the simple contact printing methodology. High performance transparent transistors built on both single nanowires and nanowire thin films are then highlighted. The final section deals with the applications of transparent metal oxide nanowire transistors in the field of transparent displays and concludes with an outlook on the current perspectives and future directions of transparent metal oxide nanowire transistors.

Chen, Di; Liu, Zhe; Liang, Bo; Wang, Xianfu; Shen, Guozhen

2012-05-01

155

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

156

Trends in development of bipolar power transistors  

Microsoft Academic Search

Monolithic integrated circuit technology was applied to bipolar power transistors which included Darlington transistors with preamplification. They are produced with two stabilizing resistors and sometimes also with two diodes for higher switching speed and for overvoltage protection respectively. Darlington transistors have higher current gain than plain silicon transistors of the same size so that they are indispensable for inverters. The

V. A. Potapchuk

1984-01-01

157

Silicon Evanescent Amplifiers  

Microsoft Academic Search

Optical amplifiers are important elements of photonic integrated circuits. We present a hybrid silicon evanescent amplifier utilizing a wafer bonded structure of silicon waveguide and AlGaInAs quantum wells. A chip gain of 13 dB with a power penalty of 0.5 dB at 40 Gb\\/s data amplification is demonstrated.

J. E. Bowers; Ying-hao Kuo; A. W. Fang; R. Jones; M. J. Paniccia; O. Cohen; O. Raday

2007-01-01

158

Antares laser power amplifier  

Microsoft Academic Search

The design of the Antares laser power amplifier is discussed. The power amplifier is the last stage of amplification in the 100 kJ Antares laser. A single, cylindrical, grid control, cold cathode electron gun, surrounded by 12 large aperture CO2 electron beam sustained laser discharge sectors is described. A large scale interaction between optical, mechanical, and electrical disciplines required to

R. D. Stine; G. F. Ross; C. J. Silvernail

1979-01-01

159

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

160

Excitron-laser amplifier  

NASA Astrophysics Data System (ADS)

A laser-amplifying device is described which is based on the stimulated decay of excitons in a pure crystal. An estimate is made of the gain of the device. At a typical frequency the gain is found to be appreciably large thus suggesting practical application of the laser amplifier.

Liboff, R. L.; Liu, K. C.

1982-12-01

161

Digital post-linearization of a Wideband Low Noise Amplifier for ultra-wideband wireless receivers  

Microsoft Academic Search

The scaling of CMOS Low Noise Amplifiers (LNA) comes with a reduction in supply voltage and increase in field mobility effect resulting in deterioration in linearity. This trade- off between CMOS transistor scaling and linearity is becoming more and more important as we transition into nano-scale CMOS LNA architectures. As a result, new techniques for the linearization of LNAs while

Ifiok Umoh; Tokunbo Ogunfunmi

2011-01-01

162

Transconductance Amplifier Structures With Very Small Transconductances: A Comparative Design Approach  

Microsoft Academic Search

A family of CMOS operational transconductance amplifiers (OTAs) has been designed for very small 's (of the order of nanoamperes per volt) with transistors operating in mod- erate inversion. Several OTA design schemes such as conventional, using current division, floating-gate, and bulk-driven techniques are discussed. A detailed comparison has also been made among these schemes in terms of performance characteristics

Anand Veeravalli; Edgar Sánchez-Sinencio; José Silva-Martínez

2002-01-01

163

Amplifier linearization using compact microstrip resonant cell-theory and experiment  

Microsoft Academic Search

This paper presents a novel technique for reducing the intermodulation distortions (IMDs) in power amplifiers. In this method, both second- and third-harmonic components generated by the transistor are reflected back simultaneously by the compact microstrip resonant cell (CMRC) at the input port with proper phases to mix with the fundamental signal for the reduction of IMDs. A rigorous mathematical analysis

Tsz Yin Yum; Quan Xue; Chi Hou Chan

2004-01-01

164

Tuning Broadband Microwave Amplifiers  

SciTech Connect

The PEP-II/DA {Phi} NE/ALS longitudinal feedback systems are complex wide bandwidth systems requiring analog, digital and microwave circuits. The solid-state amplifier is one of the components in the microwave circuit that is required to suppress the coupled bunch instabilities that exist in the PEP-II accelerator. The suppression is achieved by using an antenna as a kicker structure that provides an electric field in order to increase or decrease the energy of particles passing through the structure. The amplifier is made up of sixteen 30 to 35W microstrip GaAs FET modules that are combined to obtain 500W over a bandwidth of 850MHz to 1850MHz. The amplifier malfunctioned causing a reduction in the functionality and power output of the individual GaAs FET modules. The amplifier must be repaired. After repair, the amplifier must be tuned to optimize the gain while maintaining proper power output. The amplifier is tuned using microstrip circuit techniques. A variety of microstrip methods are used to obtain the proper line impedance. The result is a working amplifier that operates efficiently.

Alaniz, Gabriel

2003-09-05

165

An optically isolated amplifier  

NASA Astrophysics Data System (ADS)

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

Smith, C. J.

1982-11-01

166

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

NASA Astrophysics Data System (ADS)

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

Jiang, Cheng; Zhu, Ka-Di

2013-01-01

167

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

168

Reliability Physics Studies on Transistors.  

National Technical Information Service (NTIS)

The report describes work on the second breakdown phenomenon in transistors. Section 1 deals with a comparison of electrical test methods for observing the onset of the thermal instability which leads to second breakdown. Two types of pulsed emitter curre...

R. M. Scarlett G. C. Riddle

1966-01-01

169

Interface Doping of MNOS Transistors.  

National Technical Information Service (NTIS)

The objective of this program is threefold: First to survey interface dopants suitable for use in MNOS nonvolatile storage transistors, to identify optimum dopant materials, concentrations, and deposition techniques, and to evaluate the write characterist...

C. A. Neugebauer M. M. Barnicle

1978-01-01

170

Field-Effect Superconducting Transistor.  

National Technical Information Service (NTIS)

The operating principle and characteristics of a field-effect superconducting transistor using superconductors and a semiconductor were studied. For the application of superconducting materials to electronics, it is necessary to develop a superconducting ...

T. Nishino K. Yagi U. Kawabe

1990-01-01

171

High transconductance organic electrochemical transistors.  

PubMed

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

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

2013-01-01

172

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

173

Controlled-Avalanche Superlattice Transistor.  

National Technical Information Service (NTIS)

A novel bipolar avalanche transistor is proposed. Controlled avalanche and large current output over a significant bias region is achieved by incorporating a staircase multiplication region at the base-collector junction. The III-V materials choice, devic...

P. K. Bhattacharya A. Chin K. S. Seo

1987-01-01

174

Production Engineering Measure. Microelement Transistors.  

National Technical Information Service (NTIS)

The purpose of this task was to establish a manufacturing capability for a broad line of microelement transistors commensurate with Micromodule Program requirements. Subcontractors were established to provide devices that could be hermetically packaged an...

1965-01-01

175

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)

1981-01-01

176

Reflective Type Laser Amplifier.  

National Technical Information Service (NTIS)

Calculations have been carried out in an analysis of a reflection type laser amplifier. Electromagnetic radiation is assumed to travel at normal incidence through a system composed of air, a partially transmitting silver reflector, active media such as ru...

H. Jacobs D. A. Holmes L. Hatkin F. A. Brand

1964-01-01

177

Area detector amplifier module  

Microsoft Academic Search

The objective of the design of the Area Detector Amplifier Module (ADAM) is to obtain the high frequency response of a 2.5 × 10-7 sq cm pyro-electric detector with a 2 sq cm detector. The design essentially segments the 2 sq cm pyroelectric detector into over 107 detectors, adds a separate high gain amplifier in series with each detector, and

C. M. Redman

1976-01-01

178

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

179

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

180

Raman amplifiers for telecommunications  

Microsoft Academic Search

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

Mohammed N. Islam

2002-01-01

181

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

182

A post-SQUID ac amplifier aimed for multiplexed detector readouts  

NASA Astrophysics Data System (ADS)

We have built a room temperature amplifier based on Si JFETs (junction field effect transistors) intended for ac-coupled SQUID (superconducting quantum interference device) readouts, such as in frequency-domain multiplexed transition-edge sensor systems. The amplifier operates at 5 MHz centre frequency where it has the measured noise temperature of 27 K for a 60 ? load, which includes the noise from the active termination and the room temperature transformer. When it was driven from a SQUID with an on-chip matching transformer, flux noise of 0.45 ??0 Hz-1/2 was obtained. Additionally, we consider the potential of the recently introduced SiGe bipolar transistors for the same application. The dynamic range considerations for SQUID multiplexers, which require the use of an amplifier with a low noise temperature, are briefly discussed.

Kiviranta, Mikko; Virtanen, Antti; Seppä, Heikki; Penttilä, Jari; Hassel, Juha; Helistö, Panu

2006-05-01

183

A new Multi-Harmonic Volterra model dedicated to GaN packaged transistor or SSPA for pulse application  

Microsoft Academic Search

This paper presents a new macro modeling methodology for solid-state amplifiers (SSAs) and packaged transistors used in radar systems. The model topology is based on the principle of the harmonic superposition recently introduced by the Agilent X-parameters (TM) combined with dynamic Volterra theory. In this work, we focus on a pulsed identification method which has been made from time domain

W. Demenitroux; C. Maziere; E. Gatard; S. Dellier; C. Saboureau; M. Campovecchio; R. Quere

2011-01-01

184

Chemical Derivatization of an Array of Three Gold Microelectrodes with Polypyrrole: Fabrication of a Molecule-Based Transistor.  

National Technical Information Service (NTIS)

This document reports the fabrication of a chemically derivatized microelectrode array that can function as a transistor when immersed in an electrolyte solution. The key finding is that a small signal (charge) needed to turn on the device can be amplifie...

H. S. White G. P. Kittlesen M. S. Wrighton

1984-01-01

185

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

186

Amplified DNA Biosensors  

NASA Astrophysics Data System (ADS)

Amplified detection of DNA is a central research topic in modern bioanalytical science. Electronic or optical transduction of DNA recognition events provides readout signals for DNA biosensors. Amplification of the DNA analysis is accomplished by the coupling of nucleic acid-functionalized enzymes or nucleic acid-functionalized nanoparticles (NP) as labels for the DNA duplex formation. This chapter discusses the amplified amperometric analysis of DNA by redox enzymes, the amplified optical sensing of DNA by enzymes or DNAzymes, and the amplified voltammetric, optical, or microgravimetric analysis of DNA using metallic or semiconductor nanoparticles. Further approaches to amplify DNA detection involve the use of micro-carriers of redox compounds as labels for DNA complex formation on electrodes, or the use of micro-objects such as liposomes, that label the resulting DNA complexes on electrodes and alter the interfacial properties of the electrodes. Finally, DNA machines are used for the optical detection of DNA, and the systems are suggested as future analytical procedures that could substitute the polymerase chain reaction (PCR) process.

Willner, Itamar; Shlyahovsky, Bella; Willner, Bilha; Zayats, Maya

187

Amplified DNA in Streptomyces fradiae.  

PubMed Central

A spontaneous mutant of Streptomyces fradiae contained an amplifiable unit of DNA with a sequence length of approximately 10.5 kilobases that was amplified to approximately 500 copies per chromosome. The amplified DNA appears to be cryptic. SalI fragments of the amplified DNA were cloned into Escherichia coli to construct a restriction map and characterize the amplified DNA. The amplified DNA contained tandem repeats of the amplifiable unit of DNA. The unit had an average base composition of 71% guanine plus cytosine, similar to the chromosomal DNA of Streptomyces species. At least a portion of the amplifiable unit of DNA was present at a low copy number in the wild-type strain. The phenotype of amplified DNA was designated Ads1SF for amplified DNA sequence 1 in S. fradiae. Images

Fishman, S E; Hershberger, C L

1983-01-01

188

The thin SOI TGLDMOS transistor: a suitable power structure for low voltage applications  

NASA Astrophysics Data System (ADS)

This paper is addressed to the analysis of the trench gate LDMOS transistor (TGLDMOS) in a thin SOI technology and to investigate its suitability for low voltage power applications. The static and dynamic performances have been extensively analyzed by means of numerical simulations and compared with a conventional thin SOI power LDMOS transistor. The specific on-state resistance of the analyzed TGLDMOS structure is lower than that of the LDMOS counterpart, but the structure design has to be optimized to minimize the added contributions to the parasitic capacitances. In this sense, a modified TGLDMOS is also proposed to reduce the gate-drain capacitance and to increase the frequency capability. The expected electrical performance improvements of both TGLDMOS and modified TGLDMOS power transistors corroborate their suitability for 80 V switching and amplifying applications.

Cortés, I.; Fernández-Martínez, P.; Flores, D.; Hidalgo, S.; Rebollo, J.

2007-10-01

189

A 30 GHz bandwidth AlGaAs-GaAs HBT direct-coupled feedback amplifier  

Microsoft Academic Search

A DC to 30 GHz broadband amplifier based on the Darlington connected transistors with series and shunt resistive feedback was implemented with self-aligned AlGaAs-GaAs heterojunction bipolar transistor (HBT) technology. The measured performance shows 7.8 dB of gain with -3-dB roll-off bandwidth of 30 GHz. Measured at 1 GHz, the noise figure was 5.7 dB, 1-dB compression power was 11 dBm,

N. H. Sheng; W. J. Ho; N. L. Wang; R. L. Pierson; P. M. Asbeck; W. L. Edwards

1991-01-01

190

Quantum-well resonant-tunneling transistors  

Microsoft Academic Search

The authors demonstrate bipolar resonant-tunneling transistors and propose unipolar transistors which are formed by making direct contact with the quantum well of a resonant-tunneling diode structure. The characteristics of this resonant-tunneling hot electron transistor (RHET), known as the QuESTT (quantum excited-state tunneling transistor), are examined. Both digital and microwave applications for these devices are discussed

A. C. Seabaugh; W. R. Frensley; Y. Kao; J. N. Randall; M. A. Reed

1989-01-01

191

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

192

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

193

Thermal fatigue in silicon power transistors  

Microsoft Academic Search

In silicon power transistor applications, thermal cycling of the transistor may activate a failure mechanism called thermal fatigue. This phenomenon is caused by the mechanical stresses set up by the differential in the thermal expansions of the various materials used in the assembly and heat sink of the transistor. Thermal fatigue often results in cracking of the silicon pellet or

G. A. Lang; B. J. Fehder; W. D. Williams

1970-01-01

194

Update: Researchers pencil in graphene transistors  

Microsoft Academic Search

Graphene, found in pencil marks, is a candidate material for making future transistors. It's extracted from graphite crystals using sticky tape. Graphene's weird electrical properties allow for smallest transistor yet. Silicon's remarkable run as ruler of the chip world may be nearing an end as engineers eventually lose the ability to make faster silicon transistors by making them smaller. In

Neil Savage

2008-01-01

195

High Performance Silicon Nanowire Field Effect Transistors  

Microsoft Academic Search

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

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

2003-01-01

196

Bipolar Transistor Based on Graphane  

NASA Astrophysics Data System (ADS)

Graphane is a semiconductor with an energy gap, obtained from hydrogenation of the two-dimensional grapheme sheet. Together with the two-dimensional geometry, unique transport features of graphene, and possibility of doping graphane, p and n regions can be defined so that p-n junctions become feasible with small reverse currents. Our recent analysis has shown that an ideal I-V characteristic for this type of junctions may be expected. Here, we predict the behavior of bipolar juncrion transistors based on graphane. Profiles of carriers and intrinsic parameters of the graphane transistor are calculated and discussed.

Gharekhanlou, B.; Tousaki, S. B.; Khorasani, S.

2010-11-01

197

Amplifying the Optophone  

Microsoft Academic Search

MR. CAMPBELL SWINTON'S forecast in NATURE of March 3, p. 8, has been fully verified since he wrote. On Tuesday, March 1, the Marconi Co. kindly lent me one of their three-valve amplifiers working with an S. G. Brown loud-speaking telephone and wooden trumpet. Mr. F. Swann, of the Marconi Co., personally superintended the installation, and we succeeded without much

E. E. Fournier D'Albe

1921-01-01

198

Suppression of current fluctuations in carbon nanotube field-effect transistors by applying alternating current  

Microsoft Academic Search

A method of suppressing current fluctuations in carbon nanotube field-effect transistors (CNTFETs) is proposed. We compared the time dependences of the drain current for direct current (DC) measurement and alternating current (AC) measurement with a lock-in amplifier. Drain-current fluctuations were highly suppressed by the AC with lock-in method in the small gate voltage regime. On the other hand, the current

Yasuhide Ohno; Kenzo Maehashi; Koichi Inoue; Kazuhiko Matsumoto

2008-01-01

199

A novel cascode power matching approach for high efficiency tapered traveling wave power amplifiers in SiGe BiCMOS  

Microsoft Academic Search

In this paper we present a novel cascode power matching approach for high efficiency ultra-wideband traveling wave power amplifiers using 0.25 mum SiGe HBT transistors. An inductor between the two cascode transistors increases the output impedance, the bandwidth, and the maximum output power. Design trade-offs for maximum bandwidth, gain, output power, and efficiency are discussed by means of analytical calculations

Benjamin Sewiolo; Benjamin Waldmann; Georg Fischer; Robert Weigel

2009-01-01

200

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

201

Bipolar transistor in VESTIC technology  

NASA Astrophysics Data System (ADS)

VESTIC technology was proposed as an alternative for traditional CMOS technology. It offers a new FET-type twin gate junctionless device called VeSFET. In addition, in the basic VESTIC device structure many different active devices can be made, including bipolar transistors. This allows easy integration of bipolar transistors (called here VeSBJT) with VeSFET transistors. The purpose of this paper is to investigate the expected properties of VeSBJT in order to answer the following questions: are the expected parameters of VeSBJT promising enough to justify further research and fabrication experiments, and will VeSBJTs be technologically compatible with VeSFETs? Our theoretical predictions are based on the concept of effective base width for bipolar transistors with non-plane-parallel emitter and collector junctions. The conclusion is that VeSBJT can be a device with useful characteristics. As a result, VESTIC may have the potential to become a new BiCMOS-type technology.

Ku?micz, Wies?aw; Mierzwi?ski, Piotr

2013-07-01

202

Intermodulation in heterojunction bipolar transistors  

Microsoft Academic Search

The modeling of small-signal intermodulation distortion (IMD) in heterojunction bipolar transistors (HBTs) is examined. The authors show that IMD current generated in the exponential junction is partially canceled by IMD current generated in the junction capacitance, and that this phenomenon is largely responsible for the unusually good IMD performance of these devices. Thus, a nonlinear model of the HBT must

Stephen A. Maas; Bradford L. Nelson; Donald L. Tait

1992-01-01

203

Linear circuit applications of operational amplifiers  

Microsoft Academic Search

Some of the most frequently encountered linear circuit applications of operational amplifiers are discussed in this article. Included are details of differential dc amplifiers, bridge amplifiers, analog integrators, differentiators, line-driving amplifiers, ac coupled feedback amplifiers, current-to-voltage converters, reference-voltage sources, voltage regulators, current amplifiers, and charge amplifiers.

Larry L. Schick

1971-01-01

204

High Efficiency UHF Power Amplifier.  

National Technical Information Service (NTIS)

The report describes the development and construction of an experimental High Efficiency UHF (225-400 MHz) Power Amplifier. The prime requirements for the amplifier were: 50% overall efficiency; two watt output level for 1 milliwatt input; and, operable o...

T. J. Warnagiris

1974-01-01

205

DRIFT COMPENSATED DIRECT COUPLED AMPLIFIER  

DOEpatents

An improved direct-coupled amplifier having zerolevel drift correction is described. The need for an auxiliary corrective-potential amplifier is eliminated thereby giving protection against overload saturation of the zero- level drift correcting circuit. (T.R.H.)

Windsor, A.A.

1959-05-01

206

Linear Semiconductor Optical Amplifiers  

NASA Astrophysics Data System (ADS)

The chapter reviews properties and applications of linear semiconductor optical amplifiers (SOA). Section 12.1 covers SOA basics, including working principles, material systems, structures and their growth. Booster or inline amplifiers as well as low-noise preamplifiers are classified. Section 12.2 discusses the influence of parameters like gain, noise figure, gain saturation, gain and phase dynamics, and alpha-factor. In Sect. 12.3, the application of a linear SOA as a reach extender in future access networks is addressed. The input power dynamic range is introduced, and measurements for on-off keying and phase shift keying signals are shown. Section 12.4 presents the state of the art for commercially available SOA and includes a treatment of reflective SOAs (RSOA) as well.

Bonk, René; Vallaitis, Thomas; Freude, Wolfgang; Leuthold, Juerg; Penty, Richard; Borghesani, Anna; Lealman, Ian F.

207

PEAK LIMITING AMPLIFIER  

DOEpatents

A peak voltage amplitude limiting system adapted for use with a cascade type amplifier is described. In its detailed aspects, the invention includes an amplifier having at least a first triode tube and a second triode tube, the cathode of the second tube being connected to the anode of the first tube. A peak limiter triode tube has its control grid coupled to thc anode of the second tube and its anode connected to the cathode of the second tube. The operation of the limiter is controlled by a bias voltage source connected to the control grid of the limiter tube and the output of the system is taken from the anode of the second tube.

Goldsworthy, W.W.; Robinson, J.B.

1959-03-31

208

The Antares laser power amplifier  

Microsoft Academic Search

The overall design of the Antares laser power amplifier is discussed. The power amplifier is the last stage of amplification in the 100-kJ Antares laser. In the power amplifier a single, cylindrical, grid-controlled cold-cathode, electron gun is surrounded by 12 large-aperture CO2 electron-beam sustained laser discharge sectors. Each power amplifier will deliver 18 kJ and the six modules used in

R. D. Stine; G. F. Ross; C. Silvernail

1979-01-01

209

Plasma klystron amplifier  

NASA Astrophysics Data System (ADS)

A body of dense plasma is established within a short drift tube of a klystron amplifier between input and output resonator cavities thereof to support current modulation of microwave energy by interaction with an electron beam propagated through the drift tube. The plasma is confined to a column radially spaced from the electron beam for two-stream interaction enabling enhancement of current modulation under simultaneous high-power and high frequency operation.

Uhm, Han S.

1993-05-01

210

Plasma klystron amplifier  

NASA Astrophysics Data System (ADS)

A body of dense plasma is established within a short drift tube of a klystron amplifier between input and output resonator cavities thereof to support current modulation of microwave energy by interaction with an electron beam propagated through the drift tube. The plasma is confined to a column radially spaced from the electron beam for two-stream interaction enabling enhancement of current modulation under simultaneous high-power and high frequency operation.

Uhm, Han S.

1995-01-01

211

Helical Fiber Amplifier  

DOEpatents

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

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

2002-12-17

212

Monolithic low noise amplifiers  

NASA Astrophysics Data System (ADS)

A GaAs monolithic low-noise X-band amplifier has been developed which demonstrates a noise figure of 2.8 dB with an associated gain of 8.5 dB at 12 GHz. The circuits were formed using direction implantation into semiinsulating GaAs, which is the technology of choice for low cost, high volume applications. Monolithic fabrication is described, and RF results are presented.

Maki, D. W.; Esfandiari, R.; Siracusa, M.

1981-10-01

213

Compact CPW-MS-CPW Two-Stage pHEMT Amplifier Compatible With Flip Chip Technique in V-Band Frequencies  

Microsoft Academic Search

The V-band coplanar waveguide (CPW)-microstrip line (MS)-CPW two-stage amplifier with the flip-chip bonding technique is demonstrated using 0.15 mum AlGaAs\\/InGaAs pseudomorphic high electron mobility transistor technology. The CPW is used at input and output ports for flip-chip assemblies and the MS transmission line is employed in the interstage to reduce chip size. This two-stage amplifier employs transistors as the CPW-MS

Jen-Yi Su; Chinchun Meng; Yueh-Ting Lee; Guo-Wei Huang

2008-01-01

214

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

215

Monolithic ultra-broadband transimpedance amplifiers using AlGaAs\\/GaAs HBTS  

Microsoft Academic Search

Monolithic ultra-broadband transimpedance amplifiers have been developed using AlGaAs\\/GaAs HBTs (heterojunction bipolar transistors). The amplifiers have exhibited DC to 13.4-GHz bandwidth, with an 18.1-dB gain and a 49.8-dB? transimpedance. The standard deviations in gain and 3-dB roll-off bandwidth over 2-in wafers were as small as 0.42 dB and 0.47 GHz, respectively. These results have been brought about by an optimized

Nobuo NAGANO; T. Suzaki; A. Okamoto; K. Honjo

1991-01-01

216

A quasi-planar FET amplifier in integrated finline and microstrip technique  

NASA Astrophysics Data System (ADS)

The design and performance of a single-stage 20-GHz GaAs FET amplifier in a quasi-planar technology are described. The component includes a compact wideband transition between the finline input and output ports and the microstrip impedance-matching networks for the transistor. By virtue of a novel bias network which includes a microstrip bandstop filter and a 50-ohm resistor, this transition provides unconditional stability even at frequencies below cutoff of the finline ports. The overall amplifier has a gain of 6 dB at 20 GHz, and a 3-dB bandwidth of 17 percent.

Ruxton, James; Hoefer, Wolfgang J. R.

1989-02-01

217

Up-converted 1/f PM and AM noise in linear HBT amplifiers.  

PubMed

In this paper we describe a technique to predict the 1/f phase modulation (PM) and 1/f amplitude modulation (AM) noise due to up-conversion of 1/f baseband current noise in microwave heterojunction bipolar transistor (HBT) amplifiers. We obtain an accurate model for the amplifier and find the expression for voltage gain in terms of DC bias, transistor parameters, and circuit components. Theoretical 1/f PM and AM noise sensitivities to 1/f baseband current noise are then found by applying the definitions of PM and AM noise to the gain expression of the amplifier. Measurements of PM and AM sensitivities at 500 MHz and 1 GHz were in good agreement with the values predicted by theory, verifying the validity of this technique. This method can be used to optimize amplifier design for low PM and AM noise. We show that the amplifier PM noise can be reduced by 9 dB by adjusting the value of the input coupling capacitor. PMID:18986914

Ferre-Pikal, Eva S; Savage, Frederick H

2008-08-01

218

InGaP\\/GaAs DHBTs with composite collectors for power amplifiers  

Microsoft Academic Search

InGaP\\/GaAs double heterojunction bipolar transistors (DHBTs) with composite collectors have been proposed, simulated and fabricated for power amplifier applications in wireless communication. The composite collector combines wide-bandgap (InGaP) and narrow-bandgap (GaAs) materials. InGaP provides a high breakdown field and thus can be employed to reduce collector thickness while maintaining breakdown voltage. GaAs provides high electron mobility and thus is able

Yue-Ming Hsin; Chih-Hsien Lin; Chang-Chung Fan; Shih-Tzung Su; Michael H. T. Yang; James C. H. Huang; Kun-Chuan Lin

2001-01-01

219

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

220

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

221

A dual-band SiGe HBT low noise amplifier  

Microsoft Academic Search

To adapt to the rapid development of multi-standard mobile communication, a low noise amplifier (LNA) that can operate at two frequencies of 800MHz and 1.8GHz respectively was designed. SiGe HBTs with good noise performance were used in the design. The Cascode circuit topology was adopted to reduce the Miller effect of the transistor. Inductor degeneration in emitter was introduced to

Hong-yun Xie; Zhi-yi Lu; Wan-rong Zhang; Pei Shen; Chun-bao Ding; Yun-xia You; Bo-tao Sun

2010-01-01

222

High-frequency harmonic distortion in feedback amplifiers: analysis and applications  

Microsoft Academic Search

An approach for the evaluation of high-frequency harmonic-distortion factors in feedback systems is proposed and the results obtained are applied to feedback amplifiers. Under the assumption that transistors are not driven out of their linear operating regions, small-signal analysis and conventional algebra are exploited to derive understandable and compact expressions highly improving the comprehension of harmonic-distortion generation. The impact of

Gaetano Palumbo; Salvatore Pennisi

2003-01-01

223

IF Amplifier Section in 90 nm CMOS Technology for SoC Microwave Radiometers  

Microsoft Academic Search

In this letter a novel design solution in 90 nm CMOS technology is proposed for the IF amplifier, low-pass filter and square-law power detector of a system-on-chip (SoC) microwave radiometer. To minimize the number of off-chip components (just a single capacitor) the IF filter is based on an active gmC configuration, whereas the power detector exploits the MOS transistor non-linearity,

F. Alimenti; S. Leone; G. Tasselli; V. Palazzari; L. Roselli; D. Zito

2009-01-01

224

A 59–66 GHz Highly Stable Millimeter Wave Amplifier in 130 nm CMOS Technology  

Microsoft Academic Search

The design and fabrication of four-stage cascaded mm-wave low noise amplifiers (LNAs) in a 130 nm CMOS tech- nology are presented. The simultaneous high stability factor and low noise figure are obtained using proper inductors in both gate and source of the transistor. Measured gain of 14.7 dB with a 7 GHz bandwidth has been achieved. The larger inductors are

Mehrdad Fahimnia; Mahmoud Mohammad-Taheri; Ying Wang; Ming Yu; Safieddin Safavi-Naeini

2011-01-01

225

A 65-W high-efficiency UHF GaN power amplifier  

Microsoft Academic Search

This paper presents a high-efficiency UHF power amplifier (PA) using a GaN HEMT on a SiC substrate transistor as the active device. The PA delivers 65 W with 82% power added efficiency (PAE), and 45 W with 84% PAE at 370 MHz, with supply voltages of 35 V and 28 V, respectively. Load pull techniques under Class-E conditions are used

N. D. Lopez; J. Hoversten; M. Poulton; Z. Popovic

2008-01-01

226

Implementation of digital feedback control system for switching power amplifiers on HIT-SI  

Microsoft Academic Search

Recent developments in high-power switching devices such as insulated gate bipolar transistors (IGBTs) have greatly reduced feedback-controlled power supply costs for fusion plasma experiments. The HIT-II experiment has successfully used a pulse width modulation (PWM) method for analog-based feedback control of switching power amplifiers (SPAs). However, the analog-based feedback controllers are not suited to modification of different feedback methods and

Y. Kikuchi; B. A. Nelson; A. S. Nelson; D. A. Ennis; J. S. Wrobel; T. R. Jarboe; M. Nagata

2009-01-01

227

Variable-Load Constant-Efficiency Power Amplifier for Mobile Communications Applications  

Microsoft Academic Search

A SiGe HBT Class-B power amplifier has been developed with a voltage-controlled variable load, for constant efficiency also at low power levels. The output matching network includes varactor diodes that can change the load impedance at the collector of the transistor. The load line can therefore be adjusted to provide a variable output power saturation level, shifting the peak of

G. Leuzzi; C. Micheli

2003-01-01

228

Field-effect and bipolar power transistor physics  

NASA Astrophysics Data System (ADS)

The book provides an up-to-date account of the progress made in power transistor design. It is written for electrical engineers who design power transistor circuits, device physicists and designers, and university students. Semiconductor surface theory concepts are considered along with semiconductor properties at high carrier concentrations, avalanche breakdown, avalanche breakdown improvement methods, and selected fabrication techniques. Bipolar power transistors are discussed, taking into account power transistor structures, bipolar transistor models, current gain at high carrier concentrations, current-voltage characteristics of power transistors, frequency response, switching transient, microwave transistors, transistor thermal properties, and instabilities. Field-effect (unipolar) transistors are also examined, giving attention to junction field-effect transistors, insulated gate field-effect transistors, and MOS power transistor structures and design considerations.

Blicher, A.

229

Inductorless Narrow-Band Filter/Amplifier.  

National Technical Information Service (NTIS)

An inductorless tuned circuit is described which employs a pair of directly coupled transistor stages which may be operated with a signal injected into the emitter of either transistor or may be operated as an oscillator. The transistors are selected so t...

L. L. Kleinberg

1979-01-01

230

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

231

All-optical polariton transistor.  

PubMed

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. PMID:23653190

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

2013-01-01

232

Ultralinear UHF power transistors for CATV applications  

Microsoft Academic Search

An investigation of the cross-modulation performance of UHF power transistors and its correlation with the gain parameter curves S21(IC, VCB) shows that such transistors today exhibit an inherent linearity limitation and are not optimized for ultralinear applications. This means that using higher power transistors does not result in a larger output signal with low cross-modulation distortion. Presented measurements clearly demonstrate

OTWARD MULLER

1970-01-01

233

Graphene field-effect transistors  

Microsoft Academic Search

Owing in part to scaling challenges for metal oxide semiconductor field-effect transistors (MOSFETs) and complementary metal oxide semiconductor (CMOS) logic, the semiconductor industry is placing an increased emphasis on emerging materials and devices that may provide improved MOSFET performance beyond the 22 nm node, or provide novel functionality for, e.g. 'beyond CMOS' devices. Graphene, with its novel and electron--hole symmetric

Dharmendar Reddy; Leonard F. Register; Gary D. Carpenter; Sanjay K. Banerjee

2011-01-01

234

High current transistor pulse generator  

NASA Astrophysics Data System (ADS)

A solid state pulse generator capable of delivering high current trapezoidally shaped pulses into an inductive load has been developed at SLAC. Energy stored in the capacitor bank of the pulse generator is switched to the load through a pair of Darlington transistors. A combination of diodes and Darlington transistors is used to obtain trapezoidal or triangular shaped current pulses into an inductive load and to recover the remaining energy in the same capacitor bank without reversing capacitor voltage. The transistors work in the switch mode, and the power losses are low. The rack mounted pulse generators presently used at SLAC contain a 660 microfarad storage capacitor bank and can deliver 400 amps at 800 volts into inductive loads up to 3 mH. The pulse generators are used in several different power systems, including pulse to pulse bipolar power supplies and in application with current pulses distributed into different inductive loads. The current amplitude and discharge time are controlled by the central computer system through a specially developed multichannel controller. Several years of operation with the pulse generators have proven their consistent performance and reliability.

Nesterov, V.; Cassel, R.

1991-05-01

235

A magnetic amplifier for amplifying spin-wave signal  

Microsoft Academic Search

In summary, a microstrip-line type spin-wave amplifier was demonstrated with a power gain controlled by the pump power level. Our prototype amplifier achieved a power gain of 8.7 dB at 1.3 GHz with the pump power of 14.9 dBm (31 mW). With the use of this amplifier, spin wave based devices can be cascaded in a large area network such

Mingqiang Bao; A. Khitun; JooYoung Lee; A. P. Jacob; K. L. Wang

2009-01-01

236

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

237

Radio-frequency measurement of an asymmetric single electron transistor  

NASA Astrophysics Data System (ADS)

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

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

2007-03-01

238

Solid State Power Amplifier for 805 MegaHertz at the Los Alamos Neutron Science Center  

SciTech Connect

Particle accelerators for protons, electrons, and other ion species often use high-power vacuum tubes for RF amplification, due to the high RF power requirements to accelerate these particles with high beam currents. The final power amplifier stages driving large accelerators are unable to be converted to solid-state devices with the present technology. In some instances, radiation levels preclude the use of transistors near beamlines. Work is being done worldwide to replace the RF power stages under about ten kilowatts CW with transistor amplifiers, due to the lower maintenance costs and obsolescence of power tubes in these ranges. This is especially practical where the stages drive fifty Ohm impedance and are not located in high radiation zones. The authors are doing this at the Los Alamos Neutron Science Center (LANSCE) proton linear accelerator (linac) in New Mexico. They replaced a physically-large air-cooled UHF power amplifier using a tetrode electron tube with a compact water-cooled unit based on modular amplifier pallets developed at LANSCE. Each module uses eight push-pull bipolar power transistor pairs operated in class AB. Four pallets can easily provide up to 2,800 watts of continuous RF at 805 MHz. A radial splitter and combiner parallels the modules. This amplifier has proven to be completely reliable after over 10,000 hours of operation without failure. A second unit was constructed and installed for redundancy, and the old tetrode system was removed in 1998. The compact packaging for cooling, DC power, impedance matching, RF interconnection, and power combining met the electrical and mechanical requirements. CRT display of individual collector currents and RF levels is made possible with built-in samplers and a VXI data acquisition unit.

Davis, J.L.; Lyles, J.T.M.

1998-10-19

239

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

240

Composite instrumentation amplifier for biopotentials  

Microsoft Academic Search

We present the design of an instrumentation biopotential amplifier that, (a) combines the ac coupling and high input impedance\\u000a of an ac-coupled buffer with the CMRR of a simple differential amplifier or a monolithic instrumentation amplifier, (b) improves\\u000a the CMRR by using a potentiometer without requiring either precision resistors or high-CMRR op amps, (c) illustrates how to\\u000a calculate the CMRR

R. Pallfis-Areny; J. G. Webster

1990-01-01

241

Wavelength tunable alexandrite regenerative amplifier  

SciTech Connect

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

Harter, D.J.; Bado, P.

1988-11-01

242

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

2011-11-16

243

An approximate HSPICE model for orbit low noise analog bipolar NPN transistors  

SciTech Connect

Vertical bipolar NPN transistors can be fabricated cheaply through MOSIS by using the Orbit 2 um Low Noise Analog CMOS process. The collector is formed from an N-well, the base from a p-base diffusion, and the emitter from an N-diffusion. However, since this is a CMOS process there is no buried layer in the collector. Therefore the collector resistance is quite large. Also, the minimum emitter size is 8 um {times} 8 um, which is substantially larger than many fast bipolar processes. For certain applications, though, such as common base or emitter follower amplifiers, the performance of this transistor may be quite acceptable. However, no AC SPICE model is published for this device. This paper describes a simple approximate measurement method that was used at Fermilab to formulate an HSPICE model for these transistor. This method requires only a fast pulse generator and a good digitizing oscilloscope with an active FET probe for the AC measurements. Model parameters for two transistors of different size are then given. 1 ref., 1 fig.

Zimmerman, T.

1991-07-01

244

A new type of Schottky tunnel transistor  

Microsoft Academic Search

A new type of tunnel transistor, in which electrons can tunnel through a very thin Schottky barrier between an n+- accumulation-layer formed just under a MOS gate for controlling the tunneling current and the Schottky metal, is proposed and demonstrated. This tunnel transistor has no threshold voltage in cathode current Ik vs. cathode voltage Vk curves. Theoretical calculations based on

Mitsuteru Kimura; Tadashi Matsudate

1994-01-01

245

Resonant operating mode for a transistor  

US Patent & Trademark Office Database

The PN junctions of a transistor are biased for operation in the active mode but an initial flow of current reverses the bias of the base-emitter junction causing the transistor to conduct a resonant current with a voltage less than the forward junction voltage of said base-emitter.

2011-04-26

246

Development of RF transistors: a historical prospect  

Microsoft Academic Search

The development of RF transistors went almost unnoticed until the early 1980s because, unlike Si VLSI, there were no mass consumer markets for such devices. Most applications for RF transistors had been military oriented. Recently, this has been changed drastically due to the explosive growth of the markets for civil wireless communication systems. This paper covers the evolution and current

Frank Schwierz; Juin J. Liou

2001-01-01

247

The Capabilities of UHF Power Transistors.  

National Technical Information Service (NTIS)

An assessment of the thermal and electrical behaviour of UHF power transistors is made and compared with measurements on the best devices at present available. It is concluded that a transistor with a dissipation of 50 watts and a power gain of 6 db at 40...

C. Fromberg

1966-01-01

248

UHF power transistors and Lecher line oscillators  

Microsoft Academic Search

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.

R. W. Howes

1980-01-01

249

Pass transistor based gate array architecture  

Microsoft Academic Search

This paper describes a completely new gate array architecture that fully exploits inherent advantages of pass transistor logic which a conventional architecture can not. In implementing SRAMs, our gate array achieves a 1.5 times higher density than a conventional gate array due to its different size transistors in the basic cell. An 8×8 b multiplier designed with this gate array

Y. Sasaki; K. Yano; M. Hiraki; K. Rikino; M. Miyamoto; T. Matsuura; T. Nishida; K. Seki

1995-01-01

250

Majorana Single-Charge Transistor  

NASA Astrophysics Data System (ADS)

We study transport through a Coulomb blockaded topologically nontrivial superconducting wire (with Majorana end states) contacted by metallic leads. An exact formula for the current through this interacting Majorana single-charge transistor is derived in terms of wire spectral functions. A comprehensive picture follows from three different approaches. We find Coulomb oscillations with universal halving of the finite-temperature peak conductance under strong blockade conditions, where the valley conductance mainly comes from elastic cotunneling. The nonlinear conductance exhibits finite-voltage sidebands due to anomalous tunneling involving Cooper pair splitting.

Hützen, R.; Zazunov, A.; Braunecker, B.; Yeyati, A. Levy; Egger, R.

2012-10-01

251

Optical Parametric Generators and Amplifiers  

Microsoft Academic Search

Mid-infrared parametric generators and amplifiers in quasi-phase-matched and birefirngence phase-matched nonlinear crystals\\u000a are reviewed. Broadband mid-infrared generation using collinear and noncollinear parametric interactions is discussed.\\u000a \\u000a Keywords: Mid-infrared sources; optical parametric generators and amplifiers; quasi-phasematching.

Valdas Pasiskevicius; Fredrik Laurell

252

Amplifier for Fiber Optics Application.  

National Technical Information Service (NTIS)

The patent application relates to an amplifier for use with a photodiode in an electro-optical transmission line. A transimpedance amplifier is connected to an output port of a photodiode and a T-network feedback circuit is provided as a feedback element ...

R. A. Morrison

1976-01-01

253

An Amplifier Concept for Spintronics  

SciTech Connect

Typical spin-dependent devices proposed for information processing lack one of the most important features provided by charge based logic: they do not provide gain. In this letter we show the basic concept of a spin amplifier and propose ways to amplify a spin current at room temperature.

Acremann, Y.; Yu, X.W.; Tulapurkar, A.A.; Scherz, A.; Chembrolu, V.; Katine, J.A.; Carey, M.J.; Siegmann, H.C.; Stohr, J.

2009-05-11

254

Laser amplifier developments at Mercury  

Microsoft Academic Search

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.

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

1993-01-01

255

Antares power amplifier optical system  

Microsoft Academic Search

The optical systems of the six Antares laser power amplifiers are described. These assemblies are preceded by the front end optics and followed by the target system. Each power amplifier receives an annular input beam and divides it into 12 beams which are then directed to double pass them through 12 gain regions surrounding a central electron gun. Provisions are

C. J. Silvernail; K. C. Jones

1979-01-01

256

X-band paraphase amplifier  

NASA Astrophysics Data System (ADS)

A design method for paraphase amplifiers is described. The feasibility of balun action with gain is demonstrated by means of a paraphase amplifier over the range 9-11 GHz with a gain difference between the two ways of less than 0.9 dB and deviation from antiphase of less than 3 deg.

Levent-Villegas, M.

1984-05-01

257

Development and fabrication of improved power transistor switches  

Microsoft Academic Search

A new class of high-voltage power transistors has been achieved by adapting present interdigitated thyristor processing techniques to the fabrication of NPN Si transistors. Present devices are 2.3 cm in diameter. The electrical performance obtained is consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The forward safe operating area of the experimental transistors

P. L. Hower; C. K. Chu

1976-01-01

258

ALPS: An Automatic Layouter for Pass-Transistor Cell Synthesis  

Microsoft Academic Search

The layout synthesis for pass- transistor cells (PTCs) is different from that for CMOS cells because of the various sizes of transistors used in a PTC and the imbalance in the number of pMOS and nMOS transistors. This makes it difficult to apply commonly used linear transistor placement to PTC layout. Moreover, the mixed placement with CMOS cells restricts the

Yasuhiko Sasaki; Kunihito Rikino; Kazuo Yano

1998-01-01

259

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

PubMed

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

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

2009-01-26

260

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

261

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

262

Graphene field-effect transistors  

NASA Astrophysics Data System (ADS)

Owing in part to scaling challenges for metal oxide semiconductor field-effect transistors (MOSFETs) and complementary metal oxide semiconductor (CMOS) logic, the semiconductor industry is placing an increased emphasis on emerging materials and devices that may provide improved MOSFET performance beyond the 22 nm node, or provide novel functionality for, e.g. 'beyond CMOS' devices. Graphene, with its novel and electron-hole symmetric band structure and its high carrier mobilities and thermal velocities, is one such material that has garnered a great deal of interest for both purposes. Single and few layer carbon sheets have been fabricated by a variety of techniques including mechanical exfoliation and chemical vapour deposition, and field-effect transistors have been demonstrated with room-temperature mobilities as high as 10 000 cm2 V-1 s-1. But graphene is a gapless semiconductor and gate control of current is challenging, off-state leakage currents are high, and current does not readily saturate with drain voltage. However, various ways to overcome, adapt to, or even embrace this property are now being considered for device applications. In this work we explore through illustrative examples the potential of and challenges to graphene use for conventional and novel device applications.

Reddy, Dharmendar; Register, Leonard F.; Carpenter, Gary D.; Banerjee, Sanjay K.

2011-08-01

263

An Analysis on a Dynamic Amplifier and Calibration Methods for a Pseudo-Differential Dynamic Comparator  

NASA Astrophysics Data System (ADS)

This paper analyzes a pseudo-differential dynamic comparator with a dynamic pre-amplifier. The transient gain of a dynamic pre-amplifier is derived and applied to equations of the thermal noise and the regeneration time of a comparator. This analysis enhances understanding of the roles of transistor's parameters in pre-amplifier's gain. Based on the calculated gain, two calibration methods are also analyzed. One is calibration of a load capacitance and the other is calibration of a bypass current. The analysis helps designers' estimation for the accuracy of calibration, dead-zone of a comparator with a calibration circuit, and the influence of PVT variation. The analyzed comparator uses 90-nm CMOS technology as an example and each estimation is compared with simulation results.

Paik, Daehwa; Miyahara, Masaya; Matsuzawa, Akira

264

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

265

Dispersive readout of a flux qubit using a microstrip SQUID amplifier  

NASA Astrophysics Data System (ADS)

Dispersive techniques for the readout of superconducting qubits offer the possibility of high repetition-rate quantum non-demolition measurement by avoiding dissipation close to the qubit. We demonstrate a dispersive readout scheme in which a three junction aluminum flux qubit is inductively coupled to a 1-2 GHz oscillator formed by a capacitively shunted SQUID. The SQUID in this readout oscillator acts as a nonlinear, flux-dependent inductor so that the oscillator resonance frequency depends on the state of the qubit. Readout is performed by microwave reflectometry; the reflected signal is amplified using a microstrip SQUID amplifier (MSA) with a noise temperature of a few hundred millikelvin. This noise temperature is an order of magnitude lower than that of the HEMT (high electron mobility transistor) amplifier that follows the MSA. We report measurements in both the linear (weak drive) and the bistable (strong drive) oscillator regimes.

Hoskinson, E. M.; Slichter, D. H.; Johnson, J. E.; Macklin, C.; Naaman, O.; Clarke, John; Siddiqi, I.

2010-03-01

266

A low-noise low-power amplifier for implantable device for neural signal acquisition.  

PubMed

This paper presents a low-noise low-power amplifier for implantable device for neural signal acquisition. By operating MOS transistors in the subthreshold region, smaller low-frequency noise and lower power consumption can be achieved. A low power, low-noise common-drain buffer and a low-noise, high-linearity, low pass filter are used for high frequency noise filtering. Post-layout simulation shows the input referred noise of the system is 2.19microVrms from 10Hz to 10 KHz, power consumption is 55.8microW, and the NEF is 2.53. The amplifier was fabricated using a TSMC 0.18microm 1P6M CMOS process. Simulation results show that this low-noise, low-power amplifier is suitable for implantable device applications. PMID:19965237

Li, Ming-Ze; Tang, Kea-Tiong

2009-01-01

267

Length scaling of carbon nanotube transistors.  

PubMed

Carbon nanotube field-effect transistors are strong candidates in replacing or supplementing silicon technology. Although theoretical studies have projected that nanotube transistors will perform well at nanoscale device dimensions, most experimental studies have been carried out on devices that are about ten times larger than current silicon transistors. Here, we show that nanotube transistors maintain their performance as their channel length is scaled from 3 µm to 15 nm, with an absence of so-called short-channel effects. The 15-nm device has the shortest channel length and highest room-temperature conductance (0.7G?) and transconductance (40 µS) of any nanotube transistor reported to date. We also show the first experimental evidence that nanotube device performance depends significantly on contact length, in contrast to some previous reports. Data for both channel and contact length scaling were gathered by constructing multiple devices on a single carbon nanotube. Finally, we demonstrate the performance of a nanotube transistor with channel and contact lengths of 20 nm, an on-current of 10 µA, an on/off current ratio of 1 x 10?, and peak transconductance of 20 µS. These results provide an experimental forecast for carbon nanotube device performance at dimensions suitable for future transistor technology nodes. PMID:21102468

Franklin, Aaron D; Chen, Zhihong

2010-11-21

268

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

2013-05-01

269

Quantum limits on probabilistic amplifiers  

NASA Astrophysics Data System (ADS)

An ideal phase-preserving linear amplifier is a deterministic device that adds to an input signal the minimal amount of noise consistent with the constraints imposed by quantum mechanics. A noiseless linear amplifier takes an input coherent state to an amplified coherent state, but only works part of the time. Such a device is actually better than noiseless, since the output has less noise than the amplified noise of the input coherent state; for this reason we refer to such devices as immaculate. Here we bound the working probabilities of probabilistic and approximate immaculate amplifiers and construct theoretical models that achieve some of these bounds. Our chief conclusions are the following: (i) The working probability of any phase-insensitive immaculate amplifier is very small in the phase-plane region where the device works with high fidelity; (ii) phase-sensitive immaculate amplifiers that work only on coherent states sparsely distributed on a phase-plane circle centered at the origin can have a reasonably high working probability.

Pandey, Shashank; Jiang, Zhang; Combes, Joshua; Caves, Carlton M.

2013-09-01

270

A wideband dc-coupled amplifier  

Microsoft Academic Search

A method is described whereby an ac-coupled high-frequency amplifier and a dc-coupled low-frequency amplifier are connected in parallel in order to obtain a dc-coupled wideband amplifier. By using an operational amplifier which compares the output voltage with the input voltage, the low-frequency amplifier contributes to the overall gain only when the gain of the ac-coupled amplifier droops at low frequencies.

E. Janata

2003-01-01

271

A single supply biopotential amplifier.  

PubMed

A biopotential amplifier for single supply operation is presented. It uses a Driven Right Leg Circuit (DRL) to drive the patient's body to a DC common mode voltage, centering biopotential signals with respect to the amplifier's input voltage range. This scheme ensures proper range operation when a single power supply is used. The circuit described is especially suited for low consumption, battery-powered applications, requiring a single battery and avoiding switching voltage inverters to achieve dual supplies. The generic circuit is described and, as an example, a biopotential amplifier with a gain of 60 dB and a DC input range of +/-200 mV was implemented using low power operational amplifiers. A Common Mode Rejection Ratio (CMRR) of 126 dB at 50 Hz was achieved without trimming. PMID:11410389

Spinelli, E M; Martinez, N H; Mayosky, M A

2001-04-01

272

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

273

Superconducting quantum interference proximity transistor  

NASA Astrophysics Data System (ADS)

When a superconductor is placed close to a non-superconducting metal, it can induce superconducting correlations in the metal , known as the `proximity effect'. Such behaviour modifies the density of states (DOS) in the normal metal and opens a minigap with an amplitude that can be controlled by changing the phase of the superconducting order parameter. Here, we exploit such behaviour to realize a new type of interferometer, the superconducting quantum interference proximity transistor (SQUIPT), for which the operation relies on the modulation with the magnetic field of the DOS of a proximized metal embedded in a superconducting loop. Even without optimizing its design, this device shows extremely low flux noise, down to ~10-5?0Hz-1/2 (?0~=2×10-15Wb is the flux quantum) and dissipation several orders of magnitude smaller than in conventional superconducting interferometers. With optimization, the SQUIPT could significantly increase the sensitivity with which small magnetic moments are detected.

Giazotto, Francesco; Peltonen, Joonas T.; Meschke, Matthias; Pekola, Jukka P.

2010-04-01

274

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

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

275

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

PubMed

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

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

2013-08-01

276

Monolithic AlGaAs-GaAs HBT single- and dual-stage ultra-broadband amplifiers  

Microsoft Academic Search

The circuit design and performance of single- and dual-stage ultra-wideband monolithic microwave integrated circuit (MMIC) amplifiers using AlGaAs-GaAs heterojunction bipolar transistors (HBTs) are presented. The single-stage feedback amplifier has 10 dB of gain and a 3-dB bandwidth of DC to 18 GHz. The two-stage AC-coupled version achieves over 20 dB of gain and has a 3-dB bandwidth of 0.1 to

Fazal Ali; Ravi Ramachandran; Allen Podell

1991-01-01

277

Transimpedance amplifier-based full low-frequency noise characterization setup for Si\\/SiGe HBTs  

Microsoft Academic Search

An experimental setup, based on current\\/voltage conversion through transimpedance amplifiers (TAs), has been implemented for the direct full low-frequency noise (LFN) characterization of Si\\/SiGe heterojunction bipolar transistors (HBTs) in terms of base and collector short-circuit current noise sources. This setup performs a full characterization, as it measures simultaneously the two noise current sources and their correlation, thanks to an original

Laurent Bary; Mattia Borgarino; Robert Plana; Thierry Parra; Stephen J. Kovacic; Hugues Lafontaine; Jacques Graffeuil

2001-01-01

278

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

Microsoft Academic Search

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

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

2006-01-01

279

A micropower gate-bulk driven differential difference amplifier with folded telescopic cascode topology for sensor applications  

Microsoft Academic Search

A micropower high-gain, low-noise differential difference amplifier (DDA) is presented in this paper. The new circuit incorporates the gate-bulk driven transistor pairs for input stage transconductance enhancement; the very high gain folded telescopic cascode structure that permits small headroom operation; and the replica tracking bias that sustains the circuit performance against variations of process, supply voltage and temperature. The DDA

G. T. Ong; P. K. Chan

2010-01-01

280

A gain boosting method at RF frequency using active feedback and its application to RF variable gain amplifier (VGA)  

Microsoft Academic Search

A new method to achieve high voltage gain in RF-frequency range is proposed. The method adopts cascoded active feedback scheme with cascode amplifier to convert the behavior of a cascoding transistor from common gate type to quasi-common source operation. By this method, we acquire high voltage gain and increased 3 dB bandwidth simultaneously with less power consumption compared to conventional

Kwang-jin Koh; Yong-sik Youn; Hyun-kyu Yu

2002-01-01

281

X- and Ku-band amplifiers based on Si\\/SiGe HBT's and micromachined lumped components  

Microsoft Academic Search

A double mesa-structure Si\\/SiGe heterojunction bipolar transistor (HBT) and novel micromachined lumped passive components have been developed and successfully applied to the fabrication of X- and Ku-band monolithic amplifiers. The fabricated 5×5 ?m2 emitter-size Si\\/SiGe HBT exhibited a DC-current gain ? of 109, and fT and fmax of 28 and 52 GHz, respectively. Micromachined spiral inductors demonstrated resonance frequency of

Jae-Sung Rieh; Liang-Hung Lu; Linda P. B. Katehi; Pallab Bhattacharya; Edward T. Croke; George E. Ponchak; Samuel A. Alterovitz

1998-01-01

282

A high temperature precision amplifier  

SciTech Connect

A precision operational amplifier has been developed for instrumentation applications in which the circuitry must operate in ambient temperatures as high as 200 C. At 200 C the amplifier maintains an input offset voltage and current of less than 200 {mu}V and 1 nA respectively, a gain bandwidth product of 2.2 MHz, and a slew rate of 5.4 V/{mu}S. The amplifier is fabricated in a standard CMOS process and consumes 5.5 mW of power at a supply voltage of 5 V. A continuous time auto-zeroed amplifier topology is used to achieve the low offset voltage levels. At high temperatures the leakage currents of the sample and hold switches used to achieve auto-zeroing degrade the offset correction voltages stored on the hold capacitors. This degradation is reduced by using large external hold capacitors and by minimizing the diffusion area of the switches through the use of a doughnut shaped layout. The effect of the voltage degradation is reduced by sensing the offset correction voltage with a low sensitivity differential auxiliary input stage. A new input switch topology is used to reduce the amplifier`s input offset current at high temperatures.

Finvers, I.G.; Haslett, J.W.; Trofimenkoff, F.N. [Univ. of Calgary, Alberta (Canada). Dept. of Electrical and Computer Engineering

1995-02-01

283

Transistor Modeling using Advanced Circuit Simulator Technology  

Microsoft Academic Search

Abstract KRIPLANI NIKHIL, M. Transistor Modeling using advanced circuit simulator technology. (Under the direction of Michael B. Steer) The advanced MOSFET model based on the Berkeley Short Channel IGFET

NIKHIL M. KRIPLANI

284

Thermal transistor utilizing gas-liquid transition.  

PubMed

We propose a simple thermal transistor, a device to control heat current. In order to effectively change the current, we utilize the gas-liquid transition of the heat-conducting medium (fluid) because the gas region can act as a good thermal insulator. The three terminals of the transistor are located at both ends and the center of the system, and are put into contact with distinct heat baths. The key idea is a special arrangement of the three terminals. The temperature at one end (the gate temperature) is used as an input signal to control the heat current between the center (source, hot) and another end (drain, cold). Simulating the nanoscale systems of this transistor, control of heat current is demonstrated. The heat current is effectively cut off when the gate temperature is cold and it flows normally when it is hot. By using an extended version of this transistor, we also simulate a primitive application for an inverter. PMID:21405731

Komatsu, Teruhisa S; Ito, Nobuyasu

2011-01-25

285

Molecular Transistors Based On Quantum Interference  

NSDL National Science Digital Library

This article from SPIE discusses how harnessing quantum interference enables single aromatic annulene molecules to function as transistors. The article includes several illustrations which help to demonstrate the concept.

Cardamone, David M.; Stafford, Charles A.; Madzumar, Sumit

2010-10-08

286

Thermal transistor utilizing gas-liquid transition  

NASA Astrophysics Data System (ADS)

We propose a simple thermal transistor, a device to control heat current. In order to effectively change the current, we utilize the gas-liquid transition of the heat-conducting medium (fluid) because the gas region can act as a good thermal insulator. The three terminals of the transistor are located at both ends and the center of the system, and are put into contact with distinct heat baths. The key idea is a special arrangement of the three terminals. The temperature at one end (the gate temperature) is used as an input signal to control the heat current between the center (source, hot) and another end (drain, cold). Simulating the nanoscale systems of this transistor, control of heat current is demonstrated. The heat current is effectively cut off when the gate temperature is cold and it flows normally when it is hot. By using an extended version of this transistor, we also simulate a primitive application for an inverter.

Komatsu, Teruhisa S.; Ito, Nobuyasu

2011-01-01

287

Fundamental Aspects of Heterojunction Bipolar Transistor Technology.  

National Technical Information Service (NTIS)

Fundamental aspects of heterojunction bipolar transistor (HBT) technology were investigated, including Be diffusion in MBE growth, the effects of epitaxial structure variations on HBT technology, effects of selected device processing methods on HBT perfor...

D. L. Miller P. M. Asbeck

1986-01-01

288

GIMOS - A nonvolatile MOS memory transistor  

NASA Astrophysics Data System (ADS)

Characteristics of electrically alterable stacking gate nonvolatile MOS memory transistors are presented. The fabrication processes for this device are compatible with most MOS technologies. The memory mechanism is charge storage at the floating gate. The charges stored at the floating gate are injected into the floating gate from the control gate by the Fowler Nordheim tunneling process. This memory device is shown to have a very large memory window, extremely long retention time, and excellent endurance and temperature stability. Transistors have been fabricated in SOS technology. Threshold voltages for a self-aligned GIMOS p-channel device can be varied from +15 to -25 V. Similar characteristics were obtained for n-channel transistors. Based on limited data the retention time is at least 1,000 years at room temperature. Transistors were stable after 20,000 write-erase cycles and 3 x 10 to the 9th read cycles. Other stability data are also presented.

Hsu, S. T.

1981-09-01

289

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

SciTech Connect

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

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

2011-12-22

290

Design of low-noise output amplifiers for P-channel charge-coupled devices fabricated on high-resistivity silicon  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

291

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

292

Hysteresis of Electronic Transport in Graphene Transistors  

Microsoft Academic Search

Graphene field effect transistors commonly comprise graphene flakes lying on SiO2 surfaces. The gate-voltage dependent conductance shows hysteresis depending on the gate sweeping rate\\/range. It is shown here that the transistors exhibit two different kinds of hysteresis in their electrical characteristics. Charge transfer causes a positive shift in the gate voltage of the minimum conductance, while capacitive gating can cause

Haomin Wang; Yihong Wu; Chunxiao Cong; Jingzhi Shang; Ting Yu

2010-01-01

293

Carbon Nanotubes as Schottky Barrier Transistors  

Microsoft Academic Search

In the field of nano-scale devices field-effect transistors (FETs) made from carbon nanotubes (CNs) [1,2] have raised high expectations. The great progress in the fabrication of such devices has increased the excitement [3,4]. However, the understanding of the working principle - essential for device design and optimization - has remained limited. Initially, transistor action in CNFETs has been explained analogous

Stefan Heinze

2003-01-01

294

Introduction to Single-Molecule Transistor  

NASA Astrophysics Data System (ADS)

Basic concepts, within the so-called Coulomb-blockade model, of a single-molecule transistor are reviewed. Beginning with a short summary of the experimental methods, the basic model of the electron transport theory, its single-electron-transistor limit, transport through a multi-level quantum dot (molecule), and the transport through a molecule with excited (vibrational) levels are discussed. Representative experimental results are given. Theories on the interaction between tunneling electrons and the molecular vibration are briefly described.

Nishijima, Mitsuaki

295

A Single-Transistor Silicon Synapse  

Microsoft Academic Search

We have developed a new floating-gate sili- con MOS transistor for analog learning applications. The memory storage is nonvolatile; hot-electron injection and electron tunneling permit bidirectional memory updates. Because these updates depend on both the stored memory value and the transistor terminal voltages, the synapse can implement a learning function. We have derived a mem- ory-update rule from the physics

Chris Diorio; Paul Hasler; Bradley A. Minch; Carver Mead

1972-01-01

296

A single-transistor silicon synapse  

Microsoft Academic Search

We have developed a new floating-gate silicon MOS transistor for analog learning applications. The memory storage is nonvolatile; hot-electron injection and electron tunneling permit bidirectional memory updates. Because these updates depend on both the stored memory value and the transistor terminal voltages, the synapse can implement a learning function. We have derived a memory-update rule from the physics of the

C. Diorio; P. Hasler; A. Minch; C. A. Mead

1996-01-01

297

Carbon nanotube based high current transistors  

Microsoft Academic Search

We have constructed planar field-effect-transistors capable of switching currents of up to several milliamperes based on randomly placed single-walled carbon nanotubes (SWCNTs). The SWCNTs were grown using a chemical vapor deposition (CVD) process from a nickel based catalyst at a temperature of 650°C. Transistor source and drain contacts were defined using electron-beam lithography. The use of several hundreds of SWCNTs

R. Seidel; A. P. Graham; E. Unger; G. S. Duesberg; M. Liebau; W. Steinhoegl; W. Pamler; F. Kreupl

2004-01-01

298

A wideband CMOS inductorless low noise amplifier employing noise cancellation for digital TV tuner applications  

NASA Astrophysics Data System (ADS)

A wideband inductorless low noise amplifier for digital TV tuner applications is presented. The proposed LNA scheme uses a composite NMOS/PMOS cross-coupled transistor pair to provide partial cancellation of noise generated by the input transistors. The chip is implemented in SMIC 0.18 ?m CMOS technology. Measurement shows that the proposed LNA achieves 12.2-15.2 dB voltage gain from 300 to 900 MHz, the noise figure is below 3.1 dB and has a minimum value of 2.3 dB, and the best input-referred 1-dB compression point (IP1dB) is - 17 dBm at 900 MHz. The core consumes 7 mA current with a supply voltage of 1.8 V and occupies an area of 0.5 × 0.35 mm2.

Jihong, Zhang; Xuefei, Bai; Lu, Huang

2013-09-01

299

Numerical simulation of the comparative electrical performance of the permeable base transistor, opposed gate-source transistor and heterostructure launched ballistic field effect transistor  

Microsoft Academic Search

Devices operate under large signal conditions. Thus large signal simulations are required. This is illustrated for the permeable base transistor, the heterostructure bipolar transistor, and the opposed source-gate transistor. There were a number of ground-breaking results during the course of this study. The most significant is that a simulation was developed that coupled the large signal two dimensional device behavior

H. L. Grubin; J. P. Kreskovsky; M. Meyyappan; B. J. Morrison

1990-01-01

300

The Free Electron Laser Klystron Amplifier Concept  

Microsoft Academic Search

The simplest high gain free electron laser (FEL) amplifier concept is proposed. A klystron amplifier has the useful property that the various electronic processes take place in separate portions of the amplifier, rather than overlapping as in FEL amplifier with an uniform undulator. The klystron consists of two fundamental parts: succession of 2-3 cascades (modulator), and an output undulator (radiator)

E. L. Saldin; E. A. Schneidmiller; M. V. Yurkov

2003-01-01

301

High-voltage switching piezo drive amplifier  

Microsoft Academic Search

This paper describes the development and testing of a 4KVpp, 750 ma piezo drive switching amplifier. This amplifier is used to drive Piezo Fiber Composite material imbedded in a 1\\/6 scale CH-47 blade. This amplifier will allow higher harmonic control of the blade thus reducing rotor craft vibration and nose. The amplifier recycles reactive energy required to drive piezo material

Dan J. Clingman; Mike Gamble

1999-01-01

302

High-voltage switching piezo drive amplifier  

Microsoft Academic Search

This paper describes the development and testing of a 3KV, 400 ma piezo drive switching amplifier. This amplifier is used to drive Piezo Fiber Composite material embedded in a 1\\/6 scale CH-47 blade. This amplifier will allow higher harmonic control of the blade thus reducing rotor craft vibration and noise. The amplifier recycles reactive energy required to drive piezo material

Dan J. Clingman; Mike Gamble

1998-01-01

303

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

304

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

305

Low-noise thin-film transistor array for digital x-ray imaging detectors  

NASA Astrophysics Data System (ADS)

A new and novel detector structure is now being investigated to minimize the readout noise of large area TFT arrays. A conventional TFT panel consists of orthogonal arrays of gate lines and data lines. The parasitic capacitance from the crossover of these lines results in a sizable data line capacitance. During image readout, the thermal noise of the charge integrator is greatly magnified by the ratio of the data line capacitance to the feedback capacitance of the charge amplifier. The swinging of the gate voltage will also inject charges in and out of the imaging holding pixel capacitors and contribute to the switching noise in the readout image. By redesigning the layout of the TFT arrays and by coupling linear light source to the bottom side of the TFT array in the same direction as the gate lines, the crossover of gate lines and data lines can be avoided and the data line capacitance can be greatly reduced. Instead of addressing each row of transistors by the switching of the gate control voltage, linear light source with collimators are used to optically switch on and off the amorphous silicon transistors. The transistor switching noise from the swinging of the gate voltages is reduced. By minimizing the data line capacitance and avoiding the swinging of the gate control voltage, the basic TFT readout noise is minimized and lower dose x-rays images can be obtained. This design is applicable to both Direct Conversion and Indirect Conversion panels.

Lee, Denny

2011-03-01

306

Amplifying mirrors for terahertz plasmons  

NASA Astrophysics Data System (ADS)

Semiconductor plasmons have long held out a promise for terahertz generation, but competitive plasmonic mechanisms have yet to be found. Here, we introduce amplifying terahertz mirrors: planar interfaces for two-dimensional electron channels that amplify plasmons in the presence of electron drift. In contrast to existing formulations, we develop a rigorous mode matching technique that takes the complete mode spectrum into account. Mirrors are characterized by plasmon reflection and transmission coefficients whose values can increase with drift. Amplitude and power coefficients are determined, and conditions are found for their values to exceed unity. Resonators based on different combinations of amplifying mirrors are investigated, and an asymmetric configuration (consisting of two different electron channels confined between conducting planes) whose roundtrip gain can exceed unity is identified. The unusual conditions needed for oscillation are examined in detail and the general advantages of asymmetric arrangements are highlighted. Finally, the potential of mode matching as a universal tool for plasmonics is discussed.

Sydoruk, O.; Syms, R. R. A.; Solymar, L.

2012-11-01

307

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 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. PMID:24177330

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

2013-11-01

308

Sagnac interferometric multipass loop amplifier.  

PubMed

We propose and investigate experimentally an interferometrically stable, polarization-selective pulse multiplexing scheme for direct laser amplification of picosecond pulses. The basic building block of this scheme is a Sagnac loop which allows for a straightforward scaling of the pulse-multiplexing scheme. Switching the amplifier from single-pulse amplification to burst mode increases extraction efficiency, reduces parasitic non-linearities in the gain medium and allows for higher output energies. Time-frequency analysis of the amplified output pulses demonstrates the viability of this approach. PMID:23187278

Roither, S; Verhoef, A J; Mücke, O D; Reider, G A; Pugžlys, A; Baltuška, A

2012-10-22

309

Laser system using regenerative amplifier  

DOEpatents

High energy laser system 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.

Emmett, John L. (Pleasanton, CA)

1980-01-01

310

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

311

A 1-V high-performance CMOS current reference for application in a photoreceiver transimpedance amplifier  

NASA Astrophysics Data System (ADS)

In this paper we present a novel 1V current reference for a transimpedance amplifier (TIA) which provides a small dependence of the output response on temperature and process variation. The circuit is designed to drive the current tail of a photoreceiver TIA. The proposed architecture is based on a bandgap voltage reference and use an nMOS transistor at its output to produce a temperature compensation of mobility and threshold voltage (VTH) over a wide range of temperature (-40 to 100ºC) and process variation affecting VTH. This technique has been confirmed by theoretical analysis and SPICE simulations using the TSMC CMOS 0.18µm process.

Bendali, Abdelhalim; Audet, Yves

2004-10-01

312

Power added efficiency and gain improvement in MESFET amplifiers using an active harmonic loading technique  

NASA Astrophysics Data System (ADS)

A six-port-based multiharmonic load-pull setup is used to characterize a medium-power MESFET transistor for the design of microwave amplifiers. Complete load-pull measurements at the fundamental (1.7 GHz) and the second harmonic (3.4 GHz) are obtained for two bias points in class A and AB operation. It is shown that the power gain and the power added efficiency can vary up 0.6 dB and 6%, respectively, as the phase of the second harmonic load is changed.

Ghannouchi, F. M.; Beauregard, F.; Kouki, A. B.

1994-09-01

313

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

314

Physical modeling of avalanche-transistor switching  

NASA Astrophysics Data System (ADS)

The phenomenon of avalanche second breakdown in epitaxial planar transistors was studied. It is shown that there are two distinct modes of avalanche second breakdown operation: (1) due to temperature rise the thermal mode; and (2) due to excess injection of current under high voltage bias, the current mode. For a fast switching avalanche transistor, the current mode second breakdown is dominant. A two dimensional analysis is used to model the final destruction of the device. When the duration of the second breakdown in an avalanche transistor is limited however such a device is used as a rather fast and repeatable electrical switch, such as in a pulse generation circuit. To design an avalanche transistor for particular applications or to choose an avalanche transistor for a specific circuit, the fundamental relations between the basic structure of the device and its quasisteady-state operational characteristics, together with its operational limitations, are important. It is suggested that the second breakdown is a result of an expanding plasma wave.

Koo, J. C.; Pocha, M. D.

1982-08-01

315

A wideband dc-coupled amplifier  

NASA Astrophysics Data System (ADS)

A method is described whereby an ac-coupled high-frequency amplifier and a dc-coupled low-frequency amplifier are connected in parallel in order to obtain a dc-coupled wideband amplifier. By using an operational amplifier which compares the output voltage with the input voltage, the low-frequency amplifier contributes to the overall gain only when the gain of the ac-coupled amplifier droops at low frequencies. Thus, no frequency splitting networks are necessary and the excellent low-frequency features of an operational amplifier are added to those of the ac-coupled wideband amplifier. As an example, a low noise amplifier is described which exhibits a hundredfold gain, a bandwidth from dc to 550MHz, an input bias current of less than 1nA, and an output voltage range of +/-1V.

Janata, E.

2003-03-01

316

Program to develop an optical transistor and switch  

Microsoft Academic Search

Work during this period evaluated analytically the concept of multistage optical transistors based on two spectroscopically complementary materials. It is shown that very high total gains can be obtained with either of two alternatives, viz., (1) a chain of discrete complementary transistor units, or (2) a complementary transistor continuum (a concept which has no electronic analog). Whereas the total gain

T. Henningsen; M. Garbuny; R. H. Hopkins

1985-01-01

317

High power internally matched transistor of R&PC “Istok”  

Microsoft Academic Search

High power hermetically sealed, internally matched transistor for 3 cm wave length band applications with output power higher than 10 W, and associated gain higher than 13 dB, and efficiency higher than 30 % has been developed. Transistor is designed for continuous and pulse operation. Experimental results for 30 internally matched transistors are demonstrated.

L. V. Liapin; L. V. Manchenko; V. A. Pchelin; V. B. Tregubov

2008-01-01

318

Discrete transistor measuring and matching using a solid core oven.  

PubMed

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. PMID:23556833

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

2013-03-01

319

Advanced SOI CMOS transistor technology for high performance microprocessors  

Microsoft Academic Search

An overview of state of the art Silicon on Insulator CMOS transistors used for 65nm and 45nm volume manufacturing of microprocessors will be given. AMD's unique technology and transistor progression model as well as the key challenges to increase the power efficiency of microprocessor products will be described. For advanced SOI transistors stress engineering has become a standard feature since

Maciej Wiatr

2008-01-01

320

UHF Power transistors fabricated by double ion implantation  

Microsoft Academic Search

Because of its higher accuracy and reproducibility of impurity doping, ion implantation is favorable for constructing both the emitter and base junctions of transistors, especially narrow base structures like UHF or microwave transistors. It is also important in this case to minimize the emitter dip effect which appears in the double diffused transistors and often causes emitter-collector reach-through. To meet

M. Ono; S. Kikuchi; T. Tsuchimoto

1972-01-01

321

Two pieces for amplified guitar  

Microsoft Academic Search

This article addresses the aesthetic, theoretic, idiomatic, and technical problems encountered by the author while programming a computer to compose his Excursion and Artifacts for solo amplified guitar. Heading 1, “Background”, places these pieces in the greater context of the author's work and outlines his methodology. Heading 2, “Tonality”, describes a circular arrangement of the twelve chromatic degrees; positions closest

Charles Ames

1986-01-01

322

Avalanche Diode Sources and Amplifiers.  

National Technical Information Service (NTIS)

The significance of this research and development to the Air Force is the extension of the operational range of high-efficiency silicon avalanche diodes from the original L-band into the S-, C-, X-, and Ku-bands and from the oscillator mode to the amplifi...

K. K. N. Chang A. S. Clorfeine R. V. D'Aiello R. J. Ikola H. Kawamoto

1971-01-01

323

Plastic molded analog isolation amplifier  

Microsoft Academic Search

A plastic-packaged analog isolation amplifier that utilizes a capacitive coupled path for encoded signals and is capable of operating at high voltage levels is described. The assembly uses standard techniques for building plastic packages, allowing high-volume assembly at low cost without sacrificing performance. There is a small interconnect circuit which is used to capacitively couple the signal from the input

W. Meinel

1990-01-01

324

Linearisation Issues in Microwave Amplifiers  

Microsoft Academic Search

The European Union has established the TARGET network of excellence (NoE) to focus on microwave power amplifier (PA) technology research. It aims to integrate the research resources comprised of many research groups covering the full range of expertise in PA technology. TARGET'S linearisation expertise covers leading edge researchers in classical and new linearisation techniques, including feedforward, predistortion, feedback and envelope

M. S. O'Droma; J. Portilla; E. Bertran; S. Donati; T. J. Brazil; M. Rupp; R. Quay

325

Design Theory for Laser Amplifiers.  

National Technical Information Service (NTIS)

A theoretical and experimental study was carried out on laser amplification. A transmission system was set up with an oscillator, filter, amplifier, and detector. By controlling the relative time delays in firing or by changing the power input to the ampl...

H. Jacobs F. A. Brand S. Weitz C. Lo Cascio

1964-01-01

326

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

327

L Band Linear Power Amplifier.  

National Technical Information Service (NTIS)

The development of a linear power amplifier at L band suitable for application to a satellite phased array antenna is described. The main effort was devoted to the definition of the linearization technique and to its optimization. The result of the study ...

S. Padovani P. L. Faja

1974-01-01

328

Amplifier Principles - Coupling, Pt 1.  

National Technical Information Service (NTIS)

Explains the direct coupling of amplifier stages. Gives the limitations and the main advantage of direct coupling. Discusses rc coupling, showing the schematic and explaining the purpose of the components. Traces the path of an ac signal through the rc co...

1994-01-01

329

Composite instrumentation amplifier for biopotentials.  

PubMed

We present the design of an instrumentation biopotential amplifier that, (a) combines the ac coupling and high input impedance of an ac-coupled buffer with the CMRR of a simple differential amplifier or a monolithic instrumentation amplifier, (b) improves the CMRR by using a potentiometer without requiring either precision resistors or high-CMRR op amps, (c) illustrates how to calculate the CMRR for differential-input stages for either differential output or single-ended output. With our approach, for the 741 op amp, the CMRR of the differential stage exceeds 126 dB at 10 Hz and 106 dB at 100 Hz, which is higher than the 90 dB of the op amp alone. This is because a potentiometer permits mismatch of the resistor ratio, which compensates for the low CMRR of the op amp. Use of the LF355 op amp, which has a wider band-width, yields a CMRR of 126 dB at both 10 and 100 Hz. If the second stage is an instrumentation amplifier then no adjustment is necessary. Mismatch of passive components in the bootstrapped input buffer stage decreases the CMRR from 126 dB to 112 dB at 60 Hz and decreases it further at lower frequencies, but that is not a problem for the usual power-line interference. PMID:2372162

Pallás-Areny, R; Webster, J G

1990-01-01

330

Final amplifier for laser accelerators  

NASA Astrophysics Data System (ADS)

We demonstrate the existence of the severe losses due ASE and ability EDP technique to suppress it andparasitic lasing. The optimal conditions that can deliver up to kJ level energy with existing technology are presented. Keywords: Ultrahigh power lasers; Laser amplifiers.

Yanovsky, V. Chvykov V.; Kalinchenko, G.; Rousseau, P.; Maksimchuk, A.; Krushelnick, K.

2012-12-01

331

Transistors using crystalline silicon devices on glass  

DOEpatents

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

McCarthy, A.M.

1995-05-09

332

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.

Hwang, Harold

2011-08-11

333

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

334

Impact of self-heating in LF noise measurements with voltage amplifiers  

NASA Astrophysics Data System (ADS)

Voltage Amplifiers have been used to characterize the low-frequency noise of Heterojunction Bipolar Transistors (HBTs). They generally feature not only a lower noise floor, but also have less impact on simultaneous (two-port) measurements than Transimpedance Amplifiers, when moderate to high DC current regimes are considered. However, when the Device Under Test (DUT) is characterized under these regimes, common concepts such as unilateralism and frequency-independent small-signal parameters are no longer valid due to the frequency-dependent thermal response of the DUT (self-heating). It will be shown that depending on the conditions under which the measurements are carried out, the experimental data may vary for some orders of magnitude, leading to an incorrect characterization if the effect is disregarded.

Lisboa de Souza, A. A.; Nallatamby, J.-C.; Prigent, M.; Obregon, J.

2007-07-01

335

Self-aligned coupled nanowire transistor.  

PubMed

The integration of multiple functionalities into individual nanoelectronic components is increasingly explored as a means to step up computational power, or for advanced signal processing. Here, we report the fabrication of a coupled nanowire transistor, a device where two superimposed high-performance nanowire field-effect transistors capable of mutual interaction form a thyristor-like circuit. The structure embeds an internal level of signal processing, showing promise for applications in analogue computation. The device is naturally derived from a single NW via a self-aligned fabrication process. PMID:21815650

Kulmala, Tero S; Colli, Alan; Fasoli, Andrea; Lombardo, Antonio; Haque, Samiul; Ferrari, Andrea C

2011-08-10

336

Performance characteristics of nanocrystalline diamond vacuum field emission transistor array  

NASA Astrophysics Data System (ADS)

Nitrogen-incorporated nanocrystalline diamond (ND) vacuum field emission transistor (VFET) with self-aligned gate is fabricated by mold transfer microfabrication technique in conjunction with chemical vapor deposition (CVD) of nanocrystalline diamond on emitter cavity patterned on silicon-on-insulator (SOI) substrate. The fabricated ND-VFET demonstrates gate-controlled emission current with good signal amplification characteristics. The dc characteristics of the ND-VFET show well-defined cutoff, linear, and saturation regions with low gate turn-on voltage, high anode current, negligible gate intercepted current, and large dc voltage gain. The ac performance of the ND-VFET is measured, and the experimental data are analyzed using a modified small signal circuit model. The experimental results obtained for the ac voltage gain are found to agree with the theoretical model. A higher ac voltage gain is attainable by using a better test setup to eliminate the associated parasitic capacitances. The paper reveals the amplifier characteristics of the ND-VFET for potential applications in vacuum microelectronics.

Hsu, S. H.; Kang, W. P.; Davidson, J. L.; Huang, J. H.; Kerns, D. V.

2012-06-01

337

Performance characteristics of nanocrystalline diamond vacuum field emission transistor array  

NASA Astrophysics Data System (ADS)

Nitrogen-incorporated nanocrystalline diamond (ND) vacuum field emission transistor (VFET) with self-aligned gate is fabricated by mold transfer microfabrication technique in conjunction with chemical vapor deposition (CVD) of nanocrystalline diamond on emitter cavity patterned on silicon-on-insulator (SOI) substrate. The fabricated ND-VFET demonstrates gate-controlled emission current with good signal amplification characteristics. The dc characteristics of the ND-VFET show well-defined cutoff, linear, and saturation regions with low gate turn-on voltage, high anode current, negligible gate intercepted current, and large dc voltage gain. The ac performance of the ND-VFET is measured, and the experimental data are analyzed using a modified small signal circuit model. The experimental results obtained for the ac voltage gain are found to agree with the theoretical model. A higher ac voltage gain is attainable by using a better test setup to eliminate the associated parasitic capacitances. The paper reveals the amplifier characteristics of the ND-VFET for potential applications in vacuum microelectronics.

Hsu, S. H.; Kang, W. P.; Davidson, J. L.; Huang, J. H.; Kerns, D. V.

2012-05-01

338

Real Time Read-Out of Single Photon Absorption by a Field Effect Transistor with a Layer of Quantum Dots  

NASA Astrophysics Data System (ADS)

We present results of photon counting with a single photon detector based on field effect transistor with a layer of quantum dots in close proximity to the channel. Detection of a photon is achieved when photo-hole is captured by negatively charged InAs dot leading to a step-like increase of the current in the channel of the transistor. We use a transimpedance amplifier with a cryogenic stage and ac coupling on the input to convert the current steps of 1-2 nA height into voltage peaks with microsecond time resolution. We show that single photon counting with 0.3% efficiency, dark count rate below 10-8 ns-1 is then achieved, while the jitter limited by the circuit can be as low as 8.5 ns.

Kardyna?, B.; Shields, A. J.; Beattie, N. S.; Farrer, I.; Ritchie, D. A.

2005-06-01

339

Monolithic AlGaAs-GaAs HBT single- and dual-stage ultra-broadband amplifiers  

NASA Astrophysics Data System (ADS)

The circuit design and performance of single- and dual-stage ultra-wideband monolithic microwave integrated circuit (MMIC) amplifiers using AlGaAs-GaAs heterojunction bipolar transistors (HBTs) are presented. The single-stage feedback amplifier has 10 dB of gain and a 3-dB bandwidth of DC to 18 GHz. The two-stage AC-coupled version achieves over 20 dB of gain and has a 3-dB bandwidth of 0.1 to 18 GHz. These amplifiers are extremely small in size (single-stage: 24 mils x 24 mils, two-stage: 24 mils x 40 mils) since there are no reactive matching elements. This results in high chip yield and low cost.

Ali, Fazal; Ramachandran, Ravi; Podell, Allen

1991-05-01

340

Optically Isolated ECG Amplifier with Baseline Stabilization.  

National Technical Information Service (NTIS)

An electrocardiographic (ECG) amplifier that is optically isolated and suitable for use in all environments has been developed and tested in 100 experiments involving immersed humans during exercise and rest. The amplifier has less than a 10 micro A curre...

W. H. Mints W. E. Long

1981-01-01

341

Low Temperature Low Noise SOS Mosfet Amplifier.  

National Technical Information Service (NTIS)

The patent application describes a MOSFET amplifier apparatus capable of operating with low noise levels at low temperatures. The amplifier apparatus is totally self-biased and integrally contains all required lines and cross-over connections.

R. S. Roner

1975-01-01

342

The Free Electron Laser Klystron Amplifier Concept  

Microsoft Academic Search

The simplest high gain free electron laser (FEL) amplifier concept is\\u000aproposed. A klystron amplifier has the useful property that the various\\u000aelectronic processes take place in separate portions of the amplifier, rather\\u000athan overlapping as in FEL amplifier with an uniform undulator. The klystron\\u000aconsists of two fundamental parts: succession of 2-3 cascades (modulator), and\\u000aan output undulator (radiator)

E. L. Saldin; E. A. Schneidmiller; M. V. Yurkov

2003-01-01

343

[4-channel electroencephalographic amplifier with integrated microcircuits].  

PubMed

To conduct electroencephalographic investigations of stationary and moving objects a small-sized 4-channel amplifier built with integrated microcircuits has been developed. Each channel includes a pre-amplifier, main amplifier, calibrator, high and low frequency filters and a power pack. The adoption of integrated microcircuits enables it to locate the pre-amplifiers directly on the object of investigations. The device is highly sensitive and secures a greater degree of noise-protection. PMID:642753

Zhuravlev, B V; Ozhogin, M A; Simakov, A B; Stepanenko, I P; Sudakov, K V

344

Quantum-Dot Semiconductor Optical Amplifiers  

Microsoft Academic Search

This paper reviews the recent progress of quantum-dot semiconductor optical amplifiers developed as ultrawideband polarization-insensitive high-power amplifiers, high-speed signal regenerators, and wideband wavelength converters. A semiconductor optical amplifier having a gain of > 25 dB, noise figure of 20 dBm, over the record widest bandwidth of 90 nm among all kinds of optical amplifiers, and also having a penalty-free output

T. Akiyama; M. Sugawara; Y. Arakawa

2007-01-01

345

A CMOS Tunable Transimpedance Amplifier  

Microsoft Academic Search

A tunable transimpedance amplifier (TIA) is presented in this letter. By incorporating a mechanism for gain and bandwidth tuning, the TIA can be adjusted to achieve optimum circuit performance with a lowest bit-error-rate (BER) for high-speed applications. The proposed circuit is implemented in a 0.18-mum CMOS process. Consuming a dc power of 34mW from a 2.0-V supply voltage, the fabricated

Huei-Yan Hwang; Jun-Chau Chien; Tai-Yuan Chen; Liang-Hung Lu

2006-01-01

346

Design of linear transimpedance amplifiers  

Microsoft Academic Search

Current-to-voltage converters are important building blocks in analog-mixed signal processing circuits. In this paper, two very simple circuits of transimpedance amplifier used to realize a linear current-to-voltage conversion are presented. The circuits operation is not based on any charge accumulation process and the implementation of the circuits does not require any linear capacitance. The gain of the conversion and the

Chunyan Wang; Jiqiang Wang

2001-01-01

347

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

348

Electronically tuned UHF power amplifier  

Microsoft Academic Search

This electronically tunable UHF power amplifier (PA) is based upon a gallium-nitride (GaN) HEMT operated in class C. The gate input is tuned by two arrays of varactor diodes. The drain output is tuned by a three-stub tuner whose stub lengths are controlled by pin diodes. From 325 to 800 MHz (factor of 2.5:1), the PA delivers an output of

Frederick H. Raab

2011-01-01

349

Gyrotron amplifiers for plasma heating  

NASA Astrophysics Data System (ADS)

In the non-neutral, relativistic plasma Cyclotron Resonance Maser (CRM) instability, electrons gyrating in a uniform magnetic field interact with electromagnetic radiation. The action of the electric field of the radiation is to accelerate some electrons and decelerate others, depending on their location in the orbital phase. The accelerated electrons increase in momentum, gyro-radius and relativistic mass, and therefore drop in frequency and retard in phase. The opposite is true for decelerating electrons resulting in the formation of a phase bunch. If the gyrofrequency of the beam is slightly less than the wave frequency then the bunches move naturally into decelerating phase and reinforce the wave. This type of interaction has hitherto been successfully exploited in gyrotron oscillators. The research to be presented has built upon the fundamental breakthrough that occurred in gyro-amplifiers where the gain mechanism of the successful gyrotron oscillator has been exploited effectively in a Gyrotron Travelling Wave amplifier, Gyro-TWA. The design, construction and operation of a Gyro-TWA experiment will be presented. The amplifier achieved a peak power of 1.3MW, a saturated gain of 35dB in the frequency range of 8.4GHz to 10.2GHz with an efficiency of 30%.

Cross, Adrian; Whyte, Colin; He, Wenlong; Young, Alan; Robertson, Craig; Ronald, Kevin; Phelps, Alan

2008-11-01

350

Graphene based spin field effect transistor  

Microsoft Academic Search

A spin field effect transistor (FET) is proposed by utilizing a graphene nanoribbon as the channel. Similar to the conventional spin FETs, the device involves ferromagnetic metals as a source and drain; they, in turn, are connected to the graphene channel. Due to the negligible spin-orbital coupling in the carbon based materials, the bias can accomplishes spin manipulation by means

Y. G. Semenov; K. W. Kim; J. M. Zavada

2007-01-01

351

Interfacial charge transfer in nanoscale polymer transistors  

Microsoft Academic Search

Interfacial charge transfer plays an essential role in establishing the relative alignment of the metal Fermi level and the energy bands of organic semiconductors. While the details remain elusive in many systems, this charge transfer has been inferred in a number of photoemission experiments. We present electronic transport measurements in very short channel ($L < 100$ nm) transistors made from

J. H. Worne; R. Giridharagopal; K. F. Kelly; D. Natelson

2008-01-01

352

Thin-Film-Transistor Stability Investigation.  

National Technical Information Service (NTIS)

This program was undertaken to identify the key parameters required for stable operation of thin-film transistors (TFTs), to define the range of stable operation, and to assess TFT-device reliability and yield. Lead sulfide (PbS) and lead selenide semicon...

G. Kramer

1975-01-01

353

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

354

Environmentally sustainable organic field effect transistors  

Microsoft Academic Search

Environmentally sustainable systems for the design, production, and handling of electronic devices should be developed to solve the dramatic increase in electronic waste. Sustainability in plastic electronics may be the production of electronic devices from natural materials, or materials found in common commodity products accepted by society. Thereby biodegradable, biocompatible, bioresorbable, or even metabolizable electronics may become reality. Transistors with

Mihai Irimia-Vladu; Pavel A. Troshin; Melanie Reisinger; Guenther Schwabegger; Mujeeb Ullah; Reinhard Schwoediauer; Alexander Mumyatov; Marius Bodea; Jeffrey W. Fergus; Vladimir F. Razumov; Helmut Sitter; Siegfried Bauer; Niyazi Serdar Sariciftci

2010-01-01

355

Development of High Electron Mobility Transistor  

Microsoft Academic Search

The development of the high electron mobility transistor (HEMT) provides a good illustration of the way a new device emerges and evolves toward commercialization. This article will focus on these events that the author feels might be of interest to young researchers. Recent progress and future trends in HEMT technology are also described.

Takashi Mimura

2005-01-01

356

Thin Film Transistor-Addressed Display Device.  

National Technical Information Service (NTIS)

This is the final report on Contract DAAB07-72-C-0061; the objective of which was an examination of the feasibility of fabricating a multielement dot-matrix display using electroluminescent output and an integrated thin film transistor addressing array. T...

T. P. Brody F. C. Luo D. H. Davies

1977-01-01

357

Physics of Real-Space Transfer Transistors,  

National Technical Information Service (NTIS)

The physics of real-space transfer transistors has been studied by self-consistent particle Monte Carlo methods. Results of our simulations reproduce all experimentally known features of these devices. In particular, we study and explain the reasons of ne...

I. C. Kizilyalli K. Hess

1989-01-01

358

A model for THz silicon nanotube transistor  

Microsoft Academic Search

In this work, a schematic model of single-walled silicon nanotube (SWSiNT) devices is presented aimed at advancing the understanding of nano-electronic field. The circuit model of one-dimensional SWSiNT devices is firstly proposed. The cutoff frequency of SWSiNT devices is obtained, opening up the possibility of a THz silicon nanotube transistor.

Guangcun Shan; Miao Zhang; Wei Huang

2010-01-01

359

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

360

Protection Techniques of Bipolar Power Transistors,  

National Technical Information Service (NTIS)

In order to protect power transistors from overvoltage or overcurrent, it is necessary to know device characteristics and high-voltage withstand capability and further to investigate what sort of duty is caused by what mechanism in actual equipment. The p...

M. Ichijo H. Shigekane

1987-01-01

361

Hermetically sealed silicon chip diodes and transistors  

Microsoft Academic Search

Modern computer design has created a demand for large quantities of high speed logic diodes and transistors. To be technically and economically feasible extreme reliability must be combined with high performance at the lowest possible cost. The glass sealed planar devices described in this paper were designed to fill these specific requirements. The need for a costly header was eliminated

J. L. Langdon; W. E. Mutter; R. P. Pecoraro; K. K. Schuegraf

1961-01-01

362

Monolithic integrated Raman silicon lasers and amplifiers  

Microsoft Academic Search

In this paper, a chip-scale Raman silicon laser and amplifier based on a ring resonator architecture are presented. Lasing threshold and efficiency are significantly improved from the previous experiments. Much lower pump power and smaller foot print are needed for the ring resonator amplifier compared to Raman amplifier in linear configuration due to the resonance enhancement effect. The ring resonator

Haisheng Rong; Shengbo Xu; Ying-Hao Kuo; V. Sih; M. Paniccia; O. Cohen; O. Raday

2007-01-01

363

The Need for Flexibility in Amplifier Design  

Microsoft Academic Search

Improvements in detector resolution and increases in the sophistication of nuclear experiments have placed an entirely new emphasis on linear amplifier design. Just a few years ago it was necessary to have specialized amplifiers to deal with each specific problem. The lack of flexibility now plaguing most existing linear pulse amplifying systems is often quite annoying to the user. Invariably,

W. W. Goldsworthy

1963-01-01

364

Alternative Dopants for Silica Fibre Amplifiers  

Microsoft Academic Search

Optical telecommunications systems benefit from well developed and efficient optical fibre amplifiers operating on relatively narrow bands. Recent improvements in silica fibres broadened their transmission window, allowing telecommunications almost anywhere within the 800 - 1700 nm window. Although already available amplified bandwidth is not fully used yet, long term basic research is needed to identify innovative, cheap, reliable fiber amplifiers

B. Dussardier; W. Blanc

2007-01-01

365

Kilohertz Femtosecond Ti: Sapphire Regenerative Amplifier.  

National Technical Information Service (NTIS)

To have capabilities in the near-infrared, we proposed to develop a Ti:S regenerative amplifier operating at one kilohertz. This amplifier was developed to amplify the pulses from our femtosecond Ti:S laser oscillator to the 2-3 mu J/pulse energy level. T...

N. Peyghamberian B. McGinnis

1995-01-01

366

AC instrumentation amplifier for bioimpedance measurements  

Microsoft Academic Search

The input impedance and common-mode rejection ratio requirements for an amplifier for bioimpedance measurements are analyzed, considering the capacitive components of the electrode-skin contact impedance. An AC-coupled instrumentation amplifier that fulfills those requirements, and provides both interference and noise reduction and a zero phase shift over a wide frequency band without using broadband operational amplifiers, is described.

R. Pallas-Areny; J. G. Webster

1993-01-01

367

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

368

Advancements in the gallium arsenide/nickel aluminum material system and its potential for device applications: Progress towards the realization of a metal base transistor  

NASA Astrophysics Data System (ADS)

The concept of a metal base transistor is not a new one. In 1960, Carver A. Mead published a paper proposing a tunnel-emission amplifier comprised of metal-insulator-metal-insulator-metal structure in which the two insulator layers are thin barriers that produce tunnel-effect transmission of electrons between the metal layers. The middle metal layer would be thin with respect to the electronic mean free path in it. This structure would be capable of power gain in an analogous way to a conventional bipolar transistor. However, the realization of such a device was hampered by two problems. First, the large quantum mechanical reflection of electrons at the collector barrier of the device prohibited a large gain-a device physics problem. Second, the chosen material system, aluminum metal layers and oxidized aluminum layers (Al/Alsb2Osb3) was less than ideal-a materials problem. Oxide non-uniformity and non-ideal band offsets kept the device from satisfactory performance. In this thesis a different approach to realizing a practical metal base hot electron transistor will be investigated. In this approach, Molecular Beam Epitaxy (MBE) will be used to grow structures consisting of both III-V (GaAs based) semiconductors and single-crystal metals composed of NiAl. The advantages to this new approach will be discussed with respect to overcoming both of the problems mentioned above. A brief review of hot electron transistors will be provided. A discussion of hot electron transistors will emphasize the device physics relevant to overcoming the problems associated with a simple semiconductor hot electron transistor that is structurally very similar to the first metal/oxide transistor proposed by Mead. The later part of this thesis will focus on the material science related to the realization of a metal base transistor-specifically, how NiAl and related alloys, can be successfully grown on lattice mismatched III-V semiconductor substrates and employed in hot electron structures. It is the advancements in materials research that will ultimately be responsible for the success in realizing a metal base transistor since the structure of the transistor will largely be dictated by the material system used to construct the device.

Weckwerth, Mark Vernon

369

Updated design for a low-noise, wideband transimpedance photodiode amplifier  

NASA Astrophysics Data System (ADS)

The high-speed rotation diagnostic developed for Columbia's HBT-EP tokamak requires a high quantum efficiency, very low drift detector/amplifier combination. An updated version of the circuit developed originally for the beam emission spectroscopy experiment on TFTR is being used. A low dark current (2 nA at 15 V bias), low input source capacitance (2 pF) FFD-040 N-type Si photodiode is operated in photoconductive mode. It has a quantum efficiency of 40% at the 468.6 nm (He II line that is being observed). A low-noise field-effect transistor (InterFET IFN152 with eNa=1.2 nV/?Hz) is used to reduce the noise in the transimpedance preamplifier (A250 AMPTEK op-amp) and a very high speed (unity-gain bandwidth=200 MHz) voltage feedback amplifier (LM7171) is used to restore the frequency response up to 100 kHz. This type of detector/amplifier is photon-noise limited at this bandwidth for incident light with a power of >~2 nW. The circuit has been optimized using SIMETRIX 4.0 SPICE software and a prototype circuit has been tested successfully. Though photomultipliers and avalanche photodiodes can detect much lower light levels, for light levels >2 nW and a 10 kHz bandwidth, this detector/amplifier combination is more sensitive because of the absence of excess (internally generated) noise.

Paul, S. F.; Marsala, R.

2006-10-01

370

Updated design for a low-noise, wideband transimpedance photodiode amplifier  

SciTech Connect

The high-speed rotation diagnostic developed for Columbia's HBT-EP tokamak requires a high quantum efficiency, very low drift detector/amplifier combination. An updated version of the circuit developed originally for the beam emission spectroscopy experiment on TFTR is being used. A low dark current (2 nA at 15 V bias), low input source capacitance (2 pF) FFD-040 N-type Si photodiode is operated in photoconductive mode. It has a quantum efficiency of 40% at the 468.6 nm (He II line that is being observed). A low-noise field-effect transistor (InterFET IFN152 with e{sub Na}=1.2 nV/{radical}Hz) is used to reduce the noise in the transimpedance preamplifier (A250 AMPTEK op-amp) and a very high speed (unity-gain bandwidth=200 MHz) voltage feedback amplifier (LM7171) is used to restore the frequency response up to 100 kHz. This type of detector/amplifier is photon-noise limited at this bandwidth for incident light with a power of >{approx}2 nW. The circuit has been optimized using SIMETRIX 4.0 SPICE software and a prototype circuit has been tested successfully. Though photomultipliers and avalanche photodiodes can detect much lower light levels, for light levels >2 nW and a 10 kHz bandwidth, this detector/amplifier combination is more sensitive because of the absence of excess (internally generated) noise.

Paul, S. F.; Marsala, R. [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543-0451 (United States)

2006-10-15

371

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

PubMed

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

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

2013-09-01

372

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

373

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

374

Digitally programmable composite operational amplifier applications  

NASA Astrophysics Data System (ADS)

In this study, CMOS implementation of composite operational amplifiers onto a single chip is examined. Composite operational amplifiers are realized by interconnecting two or more single operational amplifiers in any one of four high performance circuit topologies. These high performance topologies result in composite operational amplifiers having useful bandwidths that are significantly larger than those associated with their constituent operational amplifiers without sacrificing closed loop gain. Computer simulations using PSPICE are compared with experimental results for performance evaluation. As an application, a multiple feedback bandpass filter implementation is examined.

Crowell, Ronald A.

1993-09-01

375

A 65mW 5Gb\\/s\\/ch current-mode common-base transimpedance amplifier array for optical interconnects  

Microsoft Academic Search

A four-channel photoreceiver array with 20-Gb throughput has been realized in a 0.8-?m Si-SiGe heterojunction bipolar transistor technology for parallel optical interconnect applications. Each channel includes a transimpedance amplifier exploiting the current-mode common-base input configuration to achieve efficient isolation of the large input parasitic capacitance. The chip module demonstrates the -3-dB bandwidth of 4.1 GHz for 0.25-pF photodiode capacitance, the

Sung Min Park; Songcheol Hong

2003-01-01

376

High-efficient class F GaAs FET amplifiers operating with very low bias voltages for use in mobile telephones at 1.75 GHz  

Microsoft Academic Search

High-efficiency class F GaAs power FET amplifiers working with a very low drain bias voltage of 3 V, for use in portable telephones, are reported. The transistor used has an optimized gate periphery of 2000 mm and a gate length of 0.7 ?m. Under class F operation with a drain voltage of 3 V, it has demonstrated an output power

C. Duvanaud; S. Dietsche; G. Pataut; J. Obregon

1993-01-01

377

Thermally Stable Structure of InGaP/GaAs Hetero-junction Bipolar Transistor: Dual-Emitter Structure  

NASA Astrophysics Data System (ADS)

We propose a new structure of InGaP/GaAs Hetero-junction Bipolar Transistor (HBT) with dual emitter fingers for power amplifier application, which is optimized for uniform thermal distribution within the device. The optimized thermal management of the proposed HBT relaxes the current decrease by a factor of 1.41 under active current bias, and prevents current gain collapse up to VCE of 8 V, while a conventional device shows a significant collapse at VCE=6.2 V.

Lee, You Sang; Park, Chul Soon

2002-04-01

378

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

379

Josephson bifurcation amplifier: Amplifying quantum signals using a dynamical bifurcation  

NASA Astrophysics Data System (ADS)

Quantum measurements of solid-state systems, such as the readout of superconducting quantum bits challenge conventional low-noise amplification techniques. Ideally, the amplifier for a quantum measurement should minimally perturb the measured system while maintaining sufficient sensitivity to overcome the noise of subsequent elements in the amplification chain. Additionally, the drift of materials properties in solid-state systems mandates a fast acquisition rate to permit measurements in rapid succession. In this thesis, we describe the Josephson Bifurcation Amplifier (JBA) which was developed to meet these requirements. The JBA exploits the sensitivity of a dynamical system - a non-linear oscillator tuned near a bifurcation point. In this new scheme, all available degrees of freedom in the dynamical system participate in information transfer and none contribute to unnecessary dissipation resulting in excess noise. We have used a superconducting tunnel junction, also known as a Josephson junction to construct our non-linear oscillator. The Josephson junction is the only electronic circuit element which remains non-linear and non-dissipative at arbitrarily low temperatures. This thesis will describe the theory and experiments demonstrating bifurcation amplification in the JBA and its application to the measurement of superconducting quantum bits. By describing the JBA as a parametrically driven oscillator, we will demonstrate that the ultimate sensitivity of the JBA is limited only by quantum fluctuations. Using this treatment, we will identify the connection between the four main aspects of working with a dynamical bifurcation: parametric amplification, squeezing, quantum activation and the Dynamical Casimir Effect.

Vijayaraghavan, Rajamani

380

Pre-amplifier with multi-stage feedback  

NASA Astrophysics Data System (ADS)

A circuit for amplifying an input signal comprises an operational amplifier, a dual operational amplifier, and a buffering operational amplifier all cascaded in the aforementioned order. The first operational amplifier amplifies the input signal with minimum noise degradation, is set up as a non-inverting amplifier stage, and has a local negative feedback loop comprising a resistor and capacitor in parallel. The dual operational amplifier has two amplifying devices. One device forms a second amplifying stage which increases the gain of the pre-amplified input signal and has a local negative feedback loop comprising a resistor.

Hagerty, James D.

1994-03-01

381

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

382

Pre-amplifier with multi-stage feedback  

NASA Astrophysics Data System (ADS)

A circuit for amplifying an input signal comprises an operational amplifier, a dual operational amplifier, and a buffering operational amplifier all cascaded in the afore-mentioned order. The first operational amplifier amplifies the input signal with minimum noise degradation, is set up as a non-inverting amplifier stage, and has a local negative feedback loop comprising a resistor and capacitor in parallel. The dual operational amplifier has two amplifying devices. One device forms a second amplifying stage which increases the gain of the pre-amplified input signal and has a local negative feedback loop comprising a resistor. The other device is a third operational amplifier which combines with the buffering operational amplifier to form an amplifying and buffering stage. The third operational amplifier connects in series to the output of the second amplifying stage. The buffering operational amplifier connects in series to the output of the third operational amplifier and buffers the amplified signal at this output. The amplifying and buffering stage has a two-stage feedback loop comprising a resistor connected between the output of the buffering operational amplifier and the inventing input of the third operational amplifier. A four-stage feedback loop includes a resistor and capacitor in parallel and connects between the output of the buffering operational amplifier and the inverting input of the first operational amplifier.

Hagerty, James D.

1994-12-01

383

The spaser as a nanoscale quantum generator and ultrafast amplifier  

NASA Astrophysics Data System (ADS)

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

Stockman, Mark I.

2010-02-01

384

Amplifier based broadband pixel for sub-millimeter wave imaging  

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

385

New Performance Indicators of Metal--Oxide--Semiconductor Field-Effect Transistors for High-Frequency Power-Conscious Design  

NASA Astrophysics Data System (ADS)

With the progress of complementary metal--oxide--semiconductor (CMOS) process technology, it is possible to apply CMOS devices to millimeter-wave amplifier design. However, the power consumption of the system becomes higher in proportion to its target frequency. Moreover, CMOS devices are biased at a point where the device achieves the highest gain and consumes much power. In order to reduce the power consumption without any compromise, we introduce two types of indicator. One works towards achieving the highest gain with the lowest power consumption. The other works towards achieving the highest linearity with consideration of the power consumption. In this work, we have shown the effectiveness of those indicators by applying measured data of the fabricated metal--oxide--semiconductor field-effect transistors (MOSFETs) to cascade common-source amplifiers.

Katayama, Kosuke; Fujishima, Minoru

2012-02-01

386

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

387

Double electron layer tunnelling transistor (DELTT)  

NASA Astrophysics Data System (ADS)

We demonstrate the double electron layer tunnelling transistor (DELTT), based on the gate control of two-dimensional-two-dimensional tunnelling in a double quantum well. Unlike previously proposed resonant tunnelling transistors, the DELTT is entirely planar and can be easily fabricated in large numbers. At 1.5 K we demonstrate peak-to-background ratios of 0268-1242/13/8A/051/img10:1 in source-drain conductance versus gate voltage and peak-to-valley ratios of 0268-1242/13/8A/051/img11:1 in the source-drain current versus source-drain voltage. Using a single DELTT in series with a load resistor, we demonstrate low-power bistable memories at 1.5 K. We also demonstrate a unipolar complementary static RAM by connecting two DELTTs in series.

Blount, M. A.; Simmons, J. A.; Moon, J. S.; Baca, W. E.; Reno, J. L.; Hafich, M. J.

1998-08-01

388

Growth of pentacene films for transistor applications  

NASA Astrophysics Data System (ADS)

Organic thin film transistors (OTFTs) are being developed in academic and industrial labs for ``disposable'' plastic electronics such as smart identification tags. Among the most promising organic semiconductors is pentacene, which yields transistors with performance similar to that of amorphous silicon. The interfaces of pentacene films with dielectric materials (gate oxide) and conductors (electrodes) play a major role in determining OTFT performance. A combination of synchrotron x-ray diffraction and atomic force microscopy was used to probe these interfaces and help optimize pentacene growth. By varying the growth conditions we were able to obtain polycrystalline films with crystallite sizes of the order of tens of microns. The connection between growth, morphology and OTFT performance will be discussed.

Malliaras, George; Headrick, Randall

2005-03-01

389

Looking inside the box: bacterial transistor arrays.  

PubMed

One often compares cells to computers, and signalling proteins to transistors. Location and wiring of those molecular transistors is paramount in defining the function of the subcellular chips. The bacterial chemotactic sensing apparatus is a large, stable assembly consisting of thousands of receptors, signal transducing kinases and linking proteins, and is responsible for the motile response of the bacterium to environmental signals, whether chemical, mechanical, or thermal. Because of its rich functional repertoire despite its relative simplicity, this chemosome has attracted much attention from both experimentalists and theoreticians, and the bacterial chemotaxis response becoming a benchmark in Systems Biology. Structural and functional models of the chemotactic device have been developed, often based on particular assumptions regarding the topology of the receptor lattice. In this issue of Molecular Microbiology, Briegel et al. provide a detailed view of the receptor arrangement, unravelling the wiring of the molecular signal processors. PMID:18484950

Shimizu, Thomas S; Le Novère, Nicolas

2008-05-12

390

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

391

Low-Voltage Tunnel Transistors for Beyond CMOS Logic  

Microsoft Academic Search

Steep subthreshold swing transistors based on interband tunneling are examined toward extending the performance of electronics systems. In particular, this review introduces and summarizes progress in the development of the tunnel field-effect transistors (TFETs) including its origin, current experimental and theoretical performance relative to the metal-oxide-semiconductor field-effect transistor (MOSFET), basic current-transport theory, design tradeoffs, and fundamental challenges. The promise of

Alan C. Seabaugh; Qin Zhang

2010-01-01

392

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

393

Organic transistors on fiber: a first step towards electronic textiles  

Microsoft Academic Search

For the first time, we demonstrate flexible transistors formed directly on fibers. This represents a significant step towards the realization of electronics textiles. Fiber transistors exhibit mobilities of >10-2 cm2\\/V-s measured at 20 V VDD. The entire transistor is fabricated without resorting to conventional lithography techniques. Patterning is achieved via shadowing from overwoven fibers. The process is compatible with textile

Josephine B. Lee; Vivek Subramanian

2003-01-01

394

Performance prediction of graphene-nanoribbon and carbon nanotube transistors  

Microsoft Academic Search

Technology exploration is carried out through the modeling of zigzag carbon nanotube field-effect-transistors (z-CNTFETs) and armchair graphene nanoribbon field-effect-transistors (a-GNRFETs) with top gate design. The devices are simulated using a top-of-the-barrier model where the energy dispersion for CNTs and GNRs is based on the tight-binding approximation. The structure of these transistors is shown in figures. In armchair GNRs, two Dirac

M. L. P. Tan; G. A. J. Amaratunga

2010-01-01

395

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

396

Unexpected Scaling of the Performance of Carbon Nanotube Transistors  

Microsoft Academic Search

We show that carbon nanotube transistors exhibit scaling that is\\u000aqualitatively different than conventional transistors. The performance depends\\u000ain an unexpected way on both the thickness and the dielectric constant of the\\u000agate oxide. Experimental measurements and theoretical calculations provide a\\u000aconsistent understanding of the scaling, which reflects the very different\\u000adevice physics of a Schottky barrier transistor with a

S. Heinze; M. Radosavljevic; J. Tersoff; Ph. Avouris

2003-01-01

397

Organic thin-film transistors of phthalocyanines  

Microsoft Academic Search

Organic thin-film field-effect transistors (OTFTs) are emerging as attractive candi- dates for low-price, large-area, and flexible circuit applications. A variety of organic com- pounds have been utilized as active semiconductor materials for OTFTs, among which phthalocyanine compounds have attracted considerable attention owing to their remarkable chemical and thermal stability as well as good field-effect performance. Here, we review re- cent

Liqiang Li; Qingxin Tang; Hongxiang Li; Wenping Hu; Xiaodi Yang; Zhigang Shuai; Yunqi Liu; Daoben Zhu

2008-01-01

398

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

399

Graphene based spin field effect transistor  

Microsoft Academic Search

A spin field effect transistor (FET) is proposed by utilizing a graphene\\u000ananoribbon as the channel. Similar to the conventional spin FETs, the device\\u000ainvolves ferromagnetic metals as a source and drain; they, in turn, are\\u000aconnected to the graphene channel. Due to the negligible spin-orbital coupling\\u000ain the carbon based materials, the bias can accomplishes spin manipulation by\\u000ameans

Y. G. Semenov; K. W. Kim; J. M. Zavada

2007-01-01

400

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

401

Interfacial charge transfer in nanoscale polymer transistors  

Microsoft Academic Search

Interfacial charge transfer plays an essential role in establishing the relative alignment of the metal Fermi level and the\\u000a energy bands of organic semiconductors. While the details remain elusive in many systems, this charge transfer has been inferred\\u000a in a number of photoemission experiments. We present electronic transport measurements in very short channel (L < 100 nm) transistors made from

Jeffrey H. Worne; Rajiv Giridharagopal; Kevin F. Kelly; Douglas Natelson

2008-01-01

402

BUSFET -- A radiation-hardened SOI transistor  

SciTech Connect

The total-dose hardness of SOI technology is limited by radiation-induced charge trapping in gate, field, and SOI buried oxides. Charge trapping in the buried oxide can lead to back-channel leakage and makes hardening SOI transistors more challenging than hardening bulk-silicon transistors. Two avenues for hardening the back-channel are (1) to use specially prepared SOI buried oxides that reduce the net amount of trapped positive charge or (2) to design transistors that are less sensitive to the effects of trapped charge in the buried oxide. In this work, the authors propose a partially-depleted SOI transistor structure for mitigating the effects of trapped charge in the buried oxide on radiation hardness. They call this structure the BUSFET--Body Under Source FET. The BUSFET utilizes a shallow source and a deep drain. As a result, the silicon depletion region at the back channel caused by radiation-induced charge trapping in the buried oxide does not form a conducting path between source and drain. Thus, the BUSFET structure design can significantly reduce radiation-induced back-channel leakage without using specially prepared buried oxides. Total dose hardness is achieved without degrading the intrinsic SEU or dose rate hardness of SOI technology. The effectiveness of the BUSFET structure for reducing total-dose back-channel leakage depends on several variables, including the top silicon film thickness and doping concentration, and the depth of the source. 3-D simulations show that for a body doping concentration of 10{sup 18} cm{sup {minus}3}, a drain bias of 3 V, and a source depth of 90 nm, a silicon film thickness of 180 nm is sufficient to almost completely eliminate radiation-induced back-channel leakage. However, for a doping concentration of 3 x 10{sup 17} cm{sup {minus}3}, a thicker silicon film (300 nm) must be used.

Schwank, J.R.; Shaneyfelt, M.R.; Draper, B.L.; Dodd, P.E.

1999-12-01

403

Development of the spin-valve transistor  

Microsoft Academic Search

As the easiest experimental approach, GMR (giant magnetoresistance) is usually measured using the current in plane (CIP)-GMR. The spin-valve transistor has previously been presented as a spectroscopic tool to measure current perpendicular to the planes (CPP)-GMR. Hot electrons cross the magnetic multilayer base quasi-ballistically and the number reaching the collector depends exponentially on the perpendicular hot electron mean free path.

D. J. Monsma; R. Vlutters; T. Shimatsu; E. G. Keim; R. H. Mollema; J. C. Lodder

1997-01-01

404

Advanced Metrology for Next Generation Transistors  

Microsoft Academic Search

This paper overviews advances in optical and electrical measurements for advanced transistor materials and processes. Optical\\u000a measurements such as ellipsometry require advances in both optical methods and optical measurement technology [1,2]. Although\\u000a laboratory based optical measurements are capable of measuring into the VUV, the availability of in-line systems is a recent\\u000a development. The Cody Lorentz model is used to describe

Alain C. Diebold

405

P-N-P-N Transistor Switches  

Microsoft Academic Search

The design, fabrication, and electrical characteristics of silicon p-n-p-n transistors with ¿>1 for use as switches is discussed. The increase of alpha with injection level can be used to construct two terminal p-n-p-n switches. The high impedance characteristic has an impedance determined chiefly by the capacitance of the junctions. This capacity is of the order of tens of micromicrofarads. The

J. L. Moll; M. Tanenbaum; J. M. Goldey; N. Holonyak

1956-01-01

406

Drain voltage scaling in carbon nanotube transistors  

Microsoft Academic Search

Decreasing the oxide thickness in carbon nanotube field-effect transistors (CNFETs) improves the turn-on behavior. However, we demonstrate that this also requires scaling the range of the drain voltage. This scaling is needed to avoid an exponential increase in off-current with drain voltage, due to modulation of the Schottky barriers at both the source and drain contact. We illustrate this with

M. Radosavljevic; S. Heinze; J. Tersoff; Ph. Avouris

2003-01-01

407

Introduction to Single-Molecule Transistor  

NASA Astrophysics Data System (ADS)

Effects, beyond the Coulomb-blockade model, of a single-molecule transistor are reviewed. The image-charge effect, elastic cotunneling effect (conduction via the Kondo effect), and the inelastic cotunneling effect [non-resonance (vibrational) inelastic electron tunneling spectroscopy] are discussed. Theories on the interaction between the Kondo effect and the molecular vibration are briefly reviewed. Inelastic Kondo effect, switching phenomena and spin-blockade effect are described. Representative experimental results are given.

Nishijima, Mitsuaki

408

Alkanethiol-based single-molecule transistors  

NASA Astrophysics Data System (ADS)

We have investigated the transport properties of alkanethiol molecules in the two-terminal and three-terminal junctions by using first-principles approaches. We observe that states around the Fermi levels are introduced in the amino-substituted butanethiol junction. It leads to a sharp increase in the current, which is credited to the resonant tunneling. The current-voltage characteristics suggest that the amino-substituted butanethiol molecular junction may be a promising candidate for field-effect transistors.

Ma, Chun-Lan; Nghiem, Diu; Chen, Yu-Chang

2008-12-01

409

Floating-Gate MOS Synapse Transistors  

Microsoft Academic Search

Our goal is to develop silicon learning systems. One impediment to achieving this goal has been the lack of a simple circuit\\u000a element combining nonvolatile analog memory storage with locally computed memory updates. Existing circuits [63, 132] typically\\u000a are large and complex; the nonvolatile floating-gate devices, such as EEPROM transistors, typically are optimized for binary-valued\\u000a storage [17], and do not

Chris Diorio; Paul Hasler; Bradley A. Minch; Carver Mead

410

Switching Characteristics of Ferroelectric Transistor Inverters  

Microsoft Academic Search

This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, ?phl and ?plh are presented along with the output voltage rise and fall times, ?rise and ?fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times

Crystal Laws; Cody Mitchell; Todd C. MacLeod; Fat D. Ho

2011-01-01

411

Large Area Printing of Organic Transistors  

NASA Astrophysics Data System (ADS)

Organic electronic systems offer the advantage of lightweight, mechanical flexibility and large area coverage at potentially lower manufacturing cost. Although the production of functioning plastic transistors using approaches such as ink jet, screen printing and stamping, has been described in the literature, no one-transistor layer has yet been fabricated using a technique appropriate for their commercial ization. The solution processability of many organics may ultimately allow for the printing of electronic devices in a printing press at high speeds and in a reel to reel configuration. However, designing chemically compatible solutions to be printed sequentially represents a significant technical barrier to achieving all-printed plastic electronic systems. The work presented here represents a step change in the fabrication of organic electronic devices. We introduce thermal transfer, a non-lithographic technique that enables printing multi-layer electronics devices via a dry (i.e. solvent-less) additive process. This high-speed method is capable of patterning a range of organic materials over large areas ( 1 m2 ) with micron dimensions and excellent electrical performance. The 0.5 m2 transistor array backplane printed via thermal transfer represent the most advanced demonstration of a novel printing technology applied to the fabrication of large area integrated electronic devices. Dry transfer printing may provide a practical route to realizing the benefits of plastic materials for electronics.

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

2003-03-01

412

Simple two-electrode biosignal amplifier.  

PubMed

A simple, cost effective circuit for a two-electrode non-differential biopotential amplifier is proposed. It uses a 'virtual ground' transimpedance amplifier and a parallel RC network for input common mode current equalisation, while the signal input impedance preserves its high value. With this innovative interface circuit, a simple non-inverting amplifier fully emulates high CMRR differential. The amplifier equivalent CMRR (typical range from 70-100 dB) is equal to the open loop gain of the operational amplifier used in the transimpedance interface stage. The circuit has very simple structure and utilises a small number of popular components. The amplifier is intended for use in various two-electrode applications, such as Holter-type monitors, defibrillators, ECG monitors, biotelemetry devices etc. PMID:16594298

Dobrev, D; Neycheva, T; Mudrov, N

2005-11-01

413

An ultralow noise amplifier for superconductive detectors  

Microsoft Academic Search

The design and construction of an AC-coupled, ultralow noise amplifier (equivalent input noise voltage En=0.33 nV\\/ square root Hz, optimum source impedance 1 k Omega at 100 kHz) is presented. The amplifier employs nine Sony 2SK 152-4 JFETS in parallel to yield the low noise result. Measurements were taken to characterize the amplifier's bandwidth, the additive voltage noise versus frequency,

G. M. Gutt; J. S. Kim; M. R. Condron; J. M. Lockhart; B. Muhlfelder

1991-01-01

414

Antares prototype power amplifier. Final report  

Microsoft Academic Search

A new power amplifier design was devised for Antares, the Los Alamos Scientific Laboratory 100-kJ COâ laser system. To test this design, a cold-cathode gun, a high-voltage test vehicle, and a prototype power amplifier were designed, built, and tested. This report describes these devices and the experimental work that demonstrated the predicted performance of the new amplifier design.

W. T. Leland; G. York; T. Ganley; D. Swanson; G. Loda; E. Yavornik; K. Riepe; R. Lindstrand; J. Comly

1978-01-01

415

Gyro-amplifiers modeling with MAGY  

Microsoft Academic Search

Recent modeling results of several experiments on gyroklystron amplifier at the Naval Research Laboratory are presented. Modeling was performed using the quasi three-dimensional, self-consistent code MAGY[1] . Amplifiers in both Ka- and W-bands have been studied [2,3]. Using known experimental input parameters, code-predicted salient amplifier performance characteristics, e.g. efficiency, bandwidth, drive curve, have been found to be in good agreement

Baruch Levush; Khanh Nguyen; Moti Botton; Alexander Vlasov Antonsen Jr.

1999-01-01

416

A 130 nm generation logic technology featuring 70 nm transistors, dual Vt transistors and 6 layers of Cu interconnects  

Microsoft Academic Search

A leading edge 130 nm generation logic technology with 6 layers of dual damascene Cu interconnects is reported. Dual Vt transistors are employed with 1.5 nm thick gate oxide and operating at 1.3 V. High Vt transistors have drive currents of 1.03 mA\\/?m and 0.5 mA\\/?m for NMOS and PMOS respectively, while low Vt transistors have currents of 1.17 mA\\/?m

S. Tyagi; M. Alavi; R. Bigwood; T. Bramblett; J. Brandenburg; W. Chen; B. Crew; M. Hussein; P. Jacob; C. Kenyon; C. Lo; B. McIntyre; Z. Ma; P. Moon; P. Nguyen; L. Rumaner; R. Schweinfurth; S. Sivakumar; M. Stettler; S. Thompson; B. Tufts; J. Xu; S. Yang; M. Bohr

2000-01-01

417

Ping-pong auto-zero amplifier with glitch reduction  

DOEpatents

A ping-pong amplifier with reduced glitching is described. The ping-pong amplifier includes a nulling amplifier coupled to a switching network. The switching network is used to auto-zero a ping amplifier within a ping-pong amplifier. The nulling amplifier drives the output of a ping amplifier to a proper output voltage level during auto-zeroing of the ping amplifier. By being at a proper output voltage level, glitches associated with transitioning between a ping amplifier and a pong amplifier are reduced or eliminated.

Larson, Mark R. (Maple Grove, MN)

2008-01-22

418

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

PubMed

Flexible pressure sensors are essential parts of an electronic skin to allow future biomedical prostheses and robots to naturally interact with humans and the environment. Mobile biomonitoring in long-term medical diagnostics is another attractive application for these sensors. Here we report the fabrication of flexible pressure-sensitive organic thin film transistors with a maximum sensitivity of 8.4 kPa(-1), a fast response time of <10 ms, high stability over >15,000 cycles and a low power consumption of <1 mW. The combination of a microstructured polydimethylsiloxane dielectric and the high-mobility semiconducting polyisoindigobithiophene-siloxane in a monolithic transistor design enabled us to operate the devices in the subthreshold regime, where the capacitance change upon compression of the dielectric is strongly amplified. We demonstrate that our sensors can be used for non-invasive, high fidelity, continuous radial artery pulse wave monitoring, which may lead to the use of flexible pressure sensors in mobile health monitoring and remote diagnostics in cardiovascular medicine. PMID:23673644

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

2013-01-01

419

Influence of amplified spontaneous emission on gain lifetime in high-aperture Ti:sapphire amplifiers.  

PubMed

We demonstrate that by lowering gain lifetime, transverse amplified spontaneous emission imposes practical limit on usable aspect ratio of large-aperture amplifiers in a high-energy Ti:sapphire system. PMID:23670763

Yanovsky, Victor; Krushelnick, Karl

2013-04-10

420

Transfer matrix analysis of the amplified spontaneous emission of DFB semiconductor laser amplifiers  

Microsoft Academic Search

Analytical expressions ware derived for the amplified spontaneous emission of a DFB semiconductor laser amplifier with reflective cavity ends. The analysis is extended to a multisection DFB structure including a phase-shifted DFB semiconductor laser amplifier. It is shown that the spontaneous emission power per unit frequency bandwidth emitted from one facet is proportional to the transmission gain and to a

T. Makino; J. Glinski

1988-01-01

421

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

NASA Astrophysics Data System (ADS)

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

Clarke, John; Kinion, Darin

2011-11-01

422

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

SciTech Connect

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

Lyles, J.; Davis, J.

1998-12-31

423

Double Integrator Magnetic Amplifier Output Circuit.  

National Technical Information Service (NTIS)

The magnetic amplifier has an integrating circuit adapted to produce a sinusoidal output voltage. Two properly rated integrating circuits are applied to the output of a push-pull magnetic amplifier. An output current may be provided flowing through the ex...

W. A. Geyher

1965-01-01

424

Varactor Tuners Eliminated an RF Amplifier  

Microsoft Academic Search

There is an urgent demand for low noise varactor tuners for use in TV receivers to meet the requirements of FCC rules. The RF amplifier has been frequently eliminated in mechanical tuners now in use, resulting in good cross-modulation characteristics and low cost. However, the elimination of the RF amplifier has not been attained in varactor tuners, because of high

Tohru Hara; Ikuo Niikura

1979-01-01

425

A micro strain gauge with mechanical amplifier  

Microsoft Academic Search

A passive micro strain gauge with a mechanical amplifier has been designed, analyzed, and tested. The mechanical amplifier provides a high gain such that residual strain in thin films can be directly measured under an optical microscope. This strain gauge can be in situ fabricated with active micro sensors or actuators for monitoring residual strain effects, and both tensile and

Liwei Lin; Albert P. Pisano; Roger T. Howe

1997-01-01

426

Gain flattening in a Raman amplifier  

Microsoft Academic Search

In designing WDM (Wavelength Division Multiplexing) systems, it is required that gain flattening must not be ignored. In this work, it is ensured that a Raman amplifier provides flat gain in a wide band, by analysis. The effects of the wavelength and the power of the pump laser on the gain flattening of a Raman amplifier are investigated. Using a

Mehmet Unal; Yusuf Hacisalihoglu; N. Ozlem Unverdi

2011-01-01

427

Analysis and design of feedforward power amplifier  

Microsoft Academic Search

A linear power amplifier is particularly emphasized on the system using a linear modulation scheme, because intermodulation distortion which causes adjacent channel interference and co-channel interference is mostly generated in a nonlinear power amplifier. In this paper, parameters of a linearization loop, such as an amplitude imbalance, a phase imbalance and a delay mismatch, are fully analyzed to get a

Sang-Gee Kang; Il-Kyoo Lee; Ki-Suk Yoo

1997-01-01

428

Fine-grain Sleep Transistor Placement Considering Leakage Feedback Gate  

Microsoft Academic Search

Abstract—Fine-grain sleep ,transistor insertion (FGSTI) technique is easier to guarantee ,circuit functionality and improves circuit noise margins while achieves a considerable leakage saving when the circuit is standby. However, when the circuit slowdown is not enough to assign sleep transistors (ST) toeach gate, a large amount of leakage feedback (LF) gates should be used to avoid floating states, and these

Yu Wang; Hui Wang; Huazhong Yang

2006-01-01

429

Simulation of Transistor Switching Circuits on the IBM 704  

Microsoft Academic Search

When the configuration of a circuit and the equivalent representations of the transistors are known, a computer program can be written to yield the performance of the circuit and the mean values of the circuit parameters. Nonlinearity of the transistors is accounted for by piece-wise linearization of an equivalent circuit. Rules of interconnection have been devised to combine this procedure

R. J. Domenico

1957-01-01

430

Single-event burnout of epitaxial bipolar transistors  

SciTech Connect

Single-Event Burnout (SEB) of bipolar junction transistors (BJTs) has been observed nondestructively. It was revealed that all the NPN BJTs, including small signal transistors, with thinner epitaxial layers were inherently susceptible to the SEB phenomenon. It was demonstrated that several design parameters of BJTs were responsible for SEB susceptibility. Additionally, destructive and nondestructive modes of SEB were identified.

Kuboyama, S.; Sugimoto, K.; Shugyo, S.; Matsuda, S. [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan); Hirao, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan)

1998-12-01

431

Transistor characteristics with Ta2O5 gate dielectric  

Microsoft Academic Search

As the gate oxide thickness decreases below 2 nm, the gate leakage current increases dramatically due to direct tunneling current. This large gate leakage current will be an obstacle to reducing gate oxide thickness for the high speed operation of future devices. A MOS transistor with Ta2O5 gate dielectric is fabricated and characterized as a possible replacement for MOS transistors

Ya-chin King; Qiang Lu; Tsu-Jae King; Chenming Hu; A. Kalnitsky; Sing-Pin Tay; Chia-Cheng Cheng

1998-01-01

432

Accurate power grid analysis with behavioral transistor network modeling  

Microsoft Academic Search

In this paper, we propose fast and efficient techniques to analyze the power grid with accurate modeling of the tran- sistor network. The solution techniques currently available for power grid analysis rely on a model of representing the transistor network as a current source. The disadvantage of the above model is that the drain capacitance of the PMOS transistors which

Anand Ramalingam; Giri V. Devarayanadurg; David Z. Pan

2007-01-01

433

Modeling of organic thin film transistors: Effect of contact resistances  

Microsoft Academic Search

Field effect transistors require an Ohmic source contact and an Ohmic drain contact for ideal operation. In many real situations, however, and specifically in organic devices, the injection of charge carriers from metals into semiconductors can be an inefficient process that is non-Ohmic. This has an adverse impact on the performance of thin film transistors and makes the analysis of

Dario Natali; Luca Fumagalli; Marco Sampietro

2007-01-01

434

A Short Story of the EKV MOS Transistor Model  

Microsoft Academic Search

The EKV MOS transistor model and design methodology evolved from the first weak inversion transistor models of the 1970's. In this first-hand account, Christian Enz chronicles the evolution of the hierarchical structure, limited parameters and flexibility of the EKV model that he developed with colleagues such as Francois Krummenacher and Eric Vittoz (the \\

Christian C. Enz

2008-01-01

435

MOS transistor modeling for RF integrated circuit design  

Microsoft Academic Search

The design of radio-frequency (RF) integrated circuits in deep-submicron CMOS processes requires accurate and scalable compact models of the MOS transistor that are valid in the GHz frequency range and even beyond. Unfortunately, the currently available compact models give inaccurate results if they are not modified adequately. This paper presents the basis of the modeling of the MOS transistor for

Christian Enz

2000-01-01

436

Linear IC SPICE macromodel developed from measured transistor parameters.  

National Technical Information Service (NTIS)

A transistor level model in a subcircuit definition is presented for the L161 micropower comparator. This macromodel is suitable for use with present-day circuit simulators such as PSPICE and SPICE-2G6. Wherever possible, measured transistor parameter val...

C. W. Raney

1991-01-01

437

Program to development an optical transistor and switch  

Microsoft Academic Search

The Optical Transistor and Switch, for which concepts and designs were developed under this program, is a device in which a radiation beam of one wavelength is controlled by a beam of a second wavelength. In contrast to other optical transistors and switches, this arrangement keeps the requirements for control and signal independent and thus adds another dimension to design.

T. Henningsen; M. Garbuny; R. H. Hopkins

1987-01-01

438

Development of organic thin film transistors based on flexible substrates  

Microsoft Academic Search

A concept for organic field effect transistors (OFETs) based on polymeric foils is presented. Starting with a short description of the basic OFET design, the selection of materials used as organic semiconductor, substrate, electrodes and gate insulator is discussed. In order to obtain reference values from well-characterised test chips, transistor measurements carried out using silicon\\/silicon dioxide substrates are described. The

S. Richter; M. Ploetner; W.-J. Fischer; M. Schneider; P.-T. Nguyen; W. Plieth; N. Kiriy; H.-J. P. Adler

2005-01-01

439

Effect of aging on radiation response of bipolar transistors  

Microsoft Academic Search

A thermally activated aging process is investigated by experimental evaluation of the change in radiation response of test PNP and NPN transistors over a wide range of emitter-base bias conditions after preirradiation elevated-temperature stress and infrared illumination. A comparison of radiation response after temperature stress for transistors with rather different ages is investigated. For \\

V. S. Pershenkov; A. Y. Slesarev; A. V. Sogoyan; V. V. Belyakov; V. B. Kekukh; A. Y. Bashin; D. V. Ivashin; V. S. Motchkine; V. N. Ulimov; V. V. Emelianov

2001-01-01

440

Calculation of the emitter efficiency of bipolar transistors  

Microsoft Academic Search

The emitter efficiency of a bipolar transistor is calculated taking heavy doping effects such as impurity band formation and band tailing into account. It is shown that in most cases these effects, rather than the minority carrier lifetime in the emitter are limiting the transistor current gain. This allows us to define an effective emitter impurity profile for use in

ROBERT P. MERTENS; HUGO J. DEMAN; ROGER J. VAN OVERSTRAETEN

1973-01-01

441

All inkjet printed self-aligned transistors and circuits applications  

Microsoft Academic Search

We fabricate devices and circuit blocks using a novel, fully-printed transistor process that self-aligns source\\/drain electrodes to gates, resulting in improved overlap capacitance. These are used with a self-aligned interconnect to realize fully-printed transistor arrays and inverters showing performance suitable for use in a range of low-cost electronics applications.

Huai-Yuan Tseng; Vivek Subramanian

2009-01-01

442

RF\\/microwave transistors: evolution, current status, and future trend  

Microsoft Academic Search

Most applications for radio frequency\\/microwave (hereafter called RF) transistors had been military oriented in the early 1980s. Recently, this has changed drastically due to the explosive growth of the markets for civil wireless communication systems. This paper gives an overview on the evolution, current status, and future trend of transistors used in RF electronic systems. Important background, development and major

Juin J. Liou; Frank Schwierz

2002-01-01

443

Post pulse shutter for laser amplifier  

DOEpatents

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.

Bradley, Laird P. (Livermore, CA); Carder, Bruce M. (Antioch, CA); Gagnon, William L. (Berkeley, CA)

1981-01-01

444

Dual-range linearized transimpedance amplifier system  

SciTech Connect

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

Wessendorf, Kurt O. (Albuquerque, NM)

2010-11-02

445

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

446

Graphene-based flexible and stretchable thin film transistors.  

PubMed

Graphene has been attracting wide attention owing to its superb electronic, thermal and mechanical properties. These properties allow great applications in the next generation of optoelectronics, where flexibility and stretchability are essential. In this context, the recent development of graphene growth/transfer and its applications in field-effect transistors are involved. In particular, we provide a detailed review on the state-of-the-art of graphene-based flexible and stretchable thin film transistors. We address the principles of fabricating high-speed graphene analog transistors and the key issues of producing an array of graphene-based transistors on flexible and stretchable substrates. It provides a platform for future work to focus on understanding and realizing high-performance graphene-based transistors. PMID:22767356

Yan, Chao; Cho, Jeong Ho; Ahn, Jong-Hyun

2012-07-06

447

Self-Consistent Study of Conjugated Aromatic Molecular Transistors  

NASA Astrophysics Data System (ADS)

We study the current through conjugated aromatic molecular transistors modulated by a transverse field. The self-consistent calculation is realized with density function theory through the standard quantum chemistry software Gaussian03 and the non-equilibrium Green's function formalism. The calculated I - V curves controlled by the transverse field present the characteristics of different organic molecular transistors, the transverse field effect of which is improved by the substitutions of nitrogen atoms or fluorine atoms. On the other hand, the asymmetry of molecular configurations to the axis connecting two sulfur atoms is in favor of realizing the transverse field modulation. Suitably designed conjugated aromatic molecular transistors possess different I - V characteristics, some of them are similar to those of metal-oxide-semiconductor field-effect transistors (MOSFET). Some of the calculated molecular devices may work as elements in graphene electronics. Our results present the richness and flexibility of molecular transistors, which describe the colorful prospect of next generation devices.

Wang, Jing; Liang, Yun-Ye; Chen, Hao; Wang, Peng; Note, R.; Mizuseki, H.; Kawazoe, Y.

2010-06-01

448

Carrier transport characteristics of small-size field effect transistors  

NASA Astrophysics Data System (ADS)

The quantum wave transport of carriers driven by an external electric field (drain bias) is studied numerically in a typical GaAs/AlGaAs heterojunction field effect transistor as a function of the gate bias. We have shown that when the size of the transistor is reduced so that quantum effects become important, the operational characteristics of the transistor are dominated by the conductance quantization effect at infinitely small drain bias and zero temperature. The conductance quantization is diminished when the temperature is increased due to the thermal excitation effect. Normal I-V characteristics of the transistor performance are obtained for small-size field effect transistor where quantum wave transmission is the principal carrier transport mechanism.

Fu, Y.; Willander, M.

1999-04-01

449

A spiking neuron circuit based on a carbon nanotube transistor  

NASA Astrophysics Data System (ADS)

A spiking neuron circuit based on a carbon nanotube (CNT) transistor is presented in this paper. The spiking neuron circuit has a crossbar architecture in which the transistor gates are connected to its row electrodes and the transistor sources are connected to its column electrodes. An electrochemical cell is incorporated in the gate of the transistor by sandwiching a hydrogen-doped poly(ethylene glycol)methyl ether (PEG) electrolyte between the CNT channel and the top gate electrode. An input spike applied to the gate triggers a dynamic drift of the hydrogen ions in the PEG electrolyte, resulting in a post-synaptic current (PSC) through the CNT channel. Spikes input into the rows trigger PSCs through multiple CNT transistors, and PSCs cumulate in the columns and integrate into a ‘soma’ circuit to trigger output spikes based on an integrate-and-fire mechanism. The spiking neuron circuit can potentially emulate biological neuron networks and their intelligent functions.

Chen, C.-L.; Kim, K.; Truong, Q.; Shen, A.; Li, Z.; Chen, Y.

2012-07-01

450

Kondo Effect in a Single Electron Transistor  

NASA Astrophysics Data System (ADS)

When a field-effect transistor is made very small, and electrons in the channel are separated from those in the leads by tunnel junctions, the transistor turns on and off every time an extra electron is added to the channel. The droplet of electrons confined in the channel of such a single-electron transistor (SET) interacts with electrons in the leads. This is in close analogy to an impurity atom interacting with the delocalized electrons in a metal, the traditional system for studying the Kondo effect.(Y. Meir, N.S. Wingreen, and P.A. Lee. PRL) 70, 2601 (1993) I will discuss measurements on a new generation of SETs that display all the aspects of the Kondo effect:(D. Goldhaber-Gordon, Hadas Shtrikman, D. Mahalu, D. Abusch-Magder, U. Meirav, and M.A. Kastner. To be published in Nature). a spin singlet forms between a localized electron in the channel and delocalized electrons in the leads, causing an enhancement of the zero-bias conductance, when the number of electrons on the artificial atom is odd but not when it is even. The system can be studied out of equilibrium by applying a voltage between the two leads, an impossible procedure in bulk Kondo systems. The spin singlet is altered by applying such a voltage or a magnetic field or by increasing the temperature, all in ways that agree with predictions. In addition, the tunability of an SET allows study of the system over a range of parameters not easily accessible to previous calculations or experiments.

Goldhaber-Gordon, David

1998-03-01

451

Organic Thin Film Transistors for Electronic Systems  

NASA Astrophysics Data System (ADS)

The surge of interest in organic thin film transistors (TFTs) has been motivated, on the one hand, by fundamental questions concerning the energetics and transport of localized carriers, and, on the other hand, by the practical advantages of electronic systems fabricated at low temperatures on flexible substrates. The overriding consideration for the usefulness of organic thin-film transistors for electronic systems has been the field-effect mobility. In this paper I will discuss materials-related factors other than mobility that influence the usefulness of organic TFTs. The subthreshold slope determines the voltage excursion that must take place below the threshold voltage to fully turn off the transistor. Typical organic TFTs have subthreshold slopes that are small compared to silicon devices, due to strongly localized states in energy gap between the more extended levels. The excursion required below threshold often has about the same magnitude as that required above threshold to reach a given level of on-current, and the speed of the system, as well as the power supply requirements, can be adversely affected by the additional required voltage swing. Organic TFTs use metallic or conducting polymer contacts that overlap the gate region, unlike the doped source and drain regions that are self-aligned to the gate in high-performance silicon technologies. A self-aligned process has not been developed for organic TFTs, and, as a result, in organic TFTs there are large parasitic capacitances that can limit system performance. If the amount of overlap is fixed by registration capabilities and can not be reduced as channel length L is reduced, the well-known silicon scaling law in which the upper frequency limit fmax scales as 1/L^2 is modified to fmax ˜ 1/L, altering significantly the economics of increased integration. The usefulness of organic TFTs is hindered by the lack of a technology that provides complementary n-channel and p-channel transistors on the same substrate. A good case can be made that the benefits of a complementary technology outweigh the gains achieved from modest improvements in single-channel device mobility, and that more effort to develop organic CMOS is warranted.

Kane, Michael

2005-03-01

452

Electroluminescence Properties of Carbon Nanotube Network Transistors  

NASA Astrophysics Data System (ADS)

Carbon nanotubes network transistors (CNNT) open a promising route for the integration of nanotubes in electronics for that they circumvent major issues related to their fabrication. [1] They also reduce device-to-device discrepancies because they combine the properties of an ensemble of nanotube species. Here, we investigated the optoelectronic properties of the CNNT fabricated from different nanotube sources and found bright electroluminescent (EL) emission. The EL is specific to the nanotube source and can be linked using absorption spectra to their diameter distribution. (1) E.S. Snow, P.M. Campbell, M.G. Ancona, Appl. Phys. Lett., 2005, 86, 033105.

St-Antoine, Benoit; Adam, Elyse; Aguirre, Carla; Menard, David; Martel, Richard

2007-03-01

453

Conjugated polyelectrolytes for organic light emitting transistors  

NASA Astrophysics Data System (ADS)

We report on solution-processed light emitting field-effect transistors (LEFETs) that incorporate symmetric high work function (WF) source and drain metal electrodes. A key architectural design is the incorporation of a conjugated polyelectrolyte (CPE) electron injection layer atop the emissive layer. The device structure also comprises a hole-transporting layer underneath the emissive layer. Both holes and electrons are injected from stable, high WF metal though the CPE layer leading to electroluminescence near the electron-injecting electrode. With the benefits of the simplicity in device fabrication, the LEFETs incorporating CPEs are interesting structures for integrated organic optoelectronic devices.

Seo, Jung Hwa; Namdas, Ebinazar B.; Gutacker, Andrea; Heeger, Alan J.; Bazan, Guillermo C.

2010-07-01

454

Organic electrochemical light emitting field effect transistors  

NASA Astrophysics Data System (ADS)

We report on the demonstration of an organic electrochemical light emitting field effect transistor. The device fabricated in bottom gate/bottom contact geometry using a conjugated polymer poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) mixed with polymer electrolyte poly(ethylene oxide) including lithium trifluoromethanesulfonate (Li triflate) as active layer and poly(vinyl alcohol) as gate dielectric. Orange-yellow light emission is observed from the device. The output characteristics (source-drain current versus the source-drain voltage) and transfer characteristics (source-drain current versus the gate voltage) of the device are reported.

Yumusak, C.; Sariciftci, N. S.

2010-07-01

455

Introduction to Single-Molecule Transistor  

NASA Astrophysics Data System (ADS)

Experimental and theoretical studies on the 2-terminal systems, which are related with a (3-terminal) single-molecule transistor, are reviewed. The measured current- bias-voltage (I-V) characteristics for the representative molecules are compared with the ab initio calculations. Molecular-vibration-induced loss of coherence and the change of the electron-transport mechanism are discussed. Mechanisms for rectification, negative differential resistance and switching of the 2-terminal systems are described. Shot-noise and thermopower studies are briefly mentioned.

Nishijima, Mitsuaki

456

Formation of molecular transistor electrodes by electromigration  

NASA Astrophysics Data System (ADS)

In this work we obtained the gaps less than 5 nm wide in the thin (15 nm) gold films. These gaps can be used for the creation of the room-temperature single-electron transistor. We demonstrated the need of deposition of Au without an adhesive layer and elaborated the technique of the creation of thin (15 nm) and narrow (200 nm) gold electrodes on Al2O3. It provides a sufficient adhesion of Au film even without a buffer layer and subsequent successive gap implementation.

Stepanov, A. S.; Soldatov, E. S.; Snigirev, O. V.

2009-10-01

457

Nonballistic Spin-Field-Effect Transistor  

NASA Astrophysics Data System (ADS)

We propose a spin-field-effect transistor based on spin-orbit coupling of both the Rashba and the Dresselhaus types. Different from earlier proposals, spin transport through our device is tolerant against spin-independent scattering processes. Hence the requirement of strictly ballistic transport can be relaxed. This follows from a unique interplay between the Dresselhaus and the Rashba coupling; these can be tuned to have equal strengths, leading to k-independent eigenspinors even in two dimensions. We discuss two-dimensional devices as well as quantum wires. In the latter, our setup presents strictly parabolic dispersions which avoids complications from anticrossings of different bands.

Schliemann, John; Egues, J. Carlos; Loss, Daniel

2003-04-01

458

Carbon Based Transistors and Nanoelectronic Devices  

NASA Astrophysics Data System (ADS)

Carbon based materials (carbon nanotube and graphene) has been extensively researched during the past decade as one of the promising materials to be used in high performance device technology. In long term it is thought that they may replace digital and/or analog electronic devices, due to their size, near-ballistic transport, and high stability. However, a more realistic point of insertion into market may be the printed nanoelectronic circuits and sensors. These applications include printed circuits for flexible electronics and displays, large-scale bendable electrical contacts, bio-membranes and bio sensors, RFID tags, etc. In order to obtain high performance thin film transistors (as the basic building block of electronic circuits) one should be able to manufacture dense arrays of all semiconducting nanotubes. Besides, graphene synthesize and transfer technology is in its infancy and there is plenty of room to improve the current techniques. To realize the performance of nanotube and graphene films in such systems, we need to economically fabricate large-scale devices based on these materials. Following that the performance control over such devices should also be considered for future design variations for broad range of applications. Here we have first investigated carbon nanotube ink as the base material for our devices. The primary ink used consisted of both metallic and semiconducting nanotubes which resulted in networks suitable for moderate-resistivity electrical connections (such as interconnects) and rfmatching circuits. Next, purified all-semiconducting nanotube ink was used to fabricate waferscale, high performance (high mobility, and high on/off ratio) thin film transistors for printed electronic applications. The parameters affecting device performance were studied in detail to establish a roadmap for the future of purified nanotube ink printed thin film transistors. The trade of between mobility and on/off ratio of such devices was studied and the effect of nanotube network density was explained in detail. On the other hand, graphene transfer technology was explored here as well. Annealing techniques were utilized to deposit clean graphene on arbitrary substrates. Raman spectroscopy and Raman data analysis was used to confirm the clean process. Furthermore, suspended graphene membrane was fabricated using single and multi-layer graphene films. This can make a major impact on graphene based transistors and bio-nano sensors technology.

Rouhi, Nima

459

Perpendicular transport in superlattice bipolar transistors (SBT)  

NASA Astrophysics Data System (ADS)

Diffusion-limited electron transport in superlattices is studied by gain measurements on heterojunction bipolar transistors with a GaAs/GaAlAs superlattice base. In the case of thin barriers, Bloch conduction is observed, while hopping between localized levels prevails for large barriers. A transition occurs between these two regimes, localization being achieved when the energy broadening induced by the electron-phonon coupling added to the disorder due to imperfect growth is of the order of the miniband width. This interpretation is supported by temperature dependence measurements of the perpendicular mobilities in relation with theoretical calculations of these mobilities.

Sibille, A.; Palmier, J. F.; Minot, C.; Harmand, J. C.; Dubon-Chevallier, C.

460

Ultrafast disk lasers and amplifiers  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

461

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

NASA Astrophysics Data System (ADS)

This paper presents experimental results of a 2-GHz band gallium nitride high electron mobility transistor (GaN HEMT) amplifier cryogenically-cooled to 60 K as a part of the cryogenic receiver front end (CRFE) for mobile base station receivers. At a temperature of 60 K, the GaN HEMT amplifier attains the maximum power added efficiency of 62%, the saturation output power of 35 dBm, the gain of 26 dB, and the noise figure of 2.6 dB when operating at class-AB biasing. The results reported herein are the first on the performance of a cryogenically-cooled GaN HEMT amplifier aiming at use in a 2-GHz band CRFE.

Suzuki, Y.; Narahashi, S.; Nojima, T.

2008-11-01

462

Design and assessment of a robust voltage amplifier with 2.5 GHz GBW and >100 kGy total dose tolerance  

NASA Astrophysics Data System (ADS)

A differential voltage amplifier with a gain-bandwidth product of 2.5Ghz and using adaptive biasing has been designed in a standard CMOS technology and assessed under radiation and temperature variations. The principle used in this ASIC will be employed in the design of a Gbps TIA with improved tolerance for ?-irradiation and temperature for an optical instrumentation (LIDAR) receiver aiming at operation in harsh environments. The voltage amplifier was tested under gamma radiation and features a gain degradation of merely 4.5% up to a total dose of 100kGy. In order to verify the radiation effects on the IC, the threshold voltage shift of the separate transistors has been investigated. Temperature characterization has shown that the amplifier features a reduction of the voltage gain by only 5.6% for a temperature range of -40 till 130 °C.

Verbeeck, J.; Leroux, P.; Steyaert, M.

2011-01-01

463

The characteristics and simulation of photo-bidirectional negative resistance transistor (PBNRT)  

Microsoft Academic Search

The bi-directional negative resistance transistor (BNRT) is an integrated device composed of two npn longitudinal bipolar transistors with common base and collector as well as an npn lateral bipolar transistor with the same base. We can get S type negative resistance characteristics between the two emitter terminals of both longitudinal transistors E1 and E2. By photosensitizing the BNRT, we have

Wei-Lian Guo; Xiao-Yun Li; Ping-Juan Niu; Shi-Lin Zhang; Tai-Shan Mo

2004-01-01

464

100 nm gate length high performance\\/low power CMOS transistor structure  

Microsoft Academic Search

We report a very high performance 100 nm gate length CMOS transistor structure operating at 1.2-1.5 V. These transistors are incorporated in a 180 nm logic technology generation. Various process enhancements are incorporated to significantly improve transistor current drive capability relative to the results published by Yang et al. (1998). Unique transistor features responsible for achieving high performance are described.

T. Ghani; S. Ahmed; P. Aminzadeh; J. Bielefeld; P. Charvat; C. Chu; M. Harper; P. Jacob; C. Jan; J. Kavalieros; C. Kenyon; R. Nagisetty; P. Packan; J. Sebastian; M. Taylor; J. Tsai; S. Tyagi; S. Yang; M. Bohr

1999-01-01

465

Progress on diamond amplified photo-cathode  

SciTech Connect

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

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

2011-03-28

466

A Low-Noise Semiconductor Optical Amplifier  

SciTech Connect

Optical amplifiers are essential devices for optical networks, optical systems, and computer communications. These amplifiers compensate for the inevitable optical loss in long-distance propagation (>50 km) or splitting (>10x). Fiber amplifiers such as the erbium-doped fiber amplifier have revolutionized the fiber-optics industry and are enjoying widespread use. Semiconductor optical amplifiers (SOAs) are an alternative technology that complements the fiber amplifiers in cost and performance. One obstacle to the widespread use of SOAs is the severity of the inevitable noise output resulting from amplified spontaneous emission (ASE). Spectral filtering is often used to reduce ASE noise, but this constrains the source spectrally, and improvement is typically limited to about 10 dB. The extra components also add cost and complexity to the final assembly. The goal of this project was to analyze, design, and take significant steps toward the realization of an innovative, low-noise SOA based on the concept of ''distributed spatial filtering'' (DSF). In DSF, we alternate active SOA segments with passive free-space diffraction regions. Since spontaneous emission radiates equally in all directions, the free-space region lengthens the amplifier for a given length of gain region, narrowing the solid angle into which the spontaneous emission is amplified [1,2]. Our innovation is to use spatial filtering in a differential manner across many segments, thereby enhancing the effect when wave-optical effects are included [3]. The structure quickly and effectively strips the ASE into the higher-order modes, quenching the ASE gain relative to the signal.

Ratowsky, R.P.; Dijaili, S.; Kallman, J.S.; Feit, M.D.; Walker, J.

1999-03-23

467

Outside Looking In: Nanotube Transistor Intracellular Sensors  

PubMed Central

Nanowire-based field-effect transistors (NWFETs), including devices with planar and three-dimensional (3D) configurations, are being actively explored as detectors for extra- and intracellular recording due to their small size and high sensitivities. Here we report the synthesis, fabrication and characterization of a new needle-shaped nanoprobe based on an active silicon nanotube transistor, ANTT, that enables high-resolution intracellular recording. In the ANTT probe, the source/drain (S/D) contacts to the silicon nanotube are fabricated on one end, passivated from external solution, and then time-dependent changes in potential can be recorded from the opposite nanotube end via the solution filling the tube. Measurements of conductance versus water-gate potential in aqueous solution show that the ANTT probe is selectively gated by potential changes within the nanotube, thus demonstrating the basic operating principle of the ANTT device. Studies interfacing the ANTT probe with spontaneously beating cardiomyocytes yielded stable intracellular action potentials similar to those reported by other electrophysiological techniques. In addition, the straightforward fabrication of ANTT devices was exploited to prepare multiple ANTT structures at the end of single probes, which enabled multiplexed recording of intracellular action potentials from single cells, and multiplexed arrays of single ANTT device probes. These studies open up unique opportunities for multisite recordings from individual cells through cellular networks.

Gao, Ruixuan; Strehle, Steffen; Tian, Bozhi; Cohen-Karni, Tzahi; Xie, Ping; Duan, Xiaojie; Qing, Quan; Lieber, Charles M.

2012-01-01

468

Outside looking in: nanotube transistor intracellular sensors.  

PubMed

Nanowire-based field-effect transistors, including devices with planar and three-dimensional configurations, are being actively explored as detectors for extra- and intracellular recording due to their small size and high sensitivities. Here we report the synthesis, fabrication, and characterization of a new needle-shaped nanoprobe based on an active silicon nanotube transistor, ANTT, that enables high-resolution intracellular recording. In the ANTT probe, the source/drain contacts to the silicon nanotube are fabricated on one end, passivated from external solution, and then time-dependent changes in potential can be recorded from the opposite nanotube end via the solution filling the tube. Measurements of conductance versus water-gate potential in aqueous solution show that the ANTT probe is selectively gated by potential changes within the nanotube, thus demonstrating the basic operating principle of the ANTT device. Studies interfacing the ANTT probe with spontaneously beating cardiomyocytes yielded stable intracellular action potentials similar to those reported by other electrophysiological techniques. In addition, the straightforward fabrication of ANTT devices was exploited to prepare multiple ANTT structures at the end of single probes, which enabled multiplexed recording of intracellular action potentials from single cells and multiplexed arrays of single ANTT device probes. These studies open up unique opportunities for multisite recordings from individual cells through cellular networks. PMID:22583370

Gao, Ruixuan; Strehle, Steffen; Tian, Bozhi; Cohen-Karni, Tzahi; Xie, Ping; Duan, Xiaojie; Qing, Quan; Lieber, Charles M

2012-05-22

469

Photoresponse characteristics of the heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

As the need for high-volume communication systems grows, especially in densely populated areas, so follows the demand for faster, less costly and more reliable network infrastructure. Fiber optics provides plenty bandwidth space that applications such as Local Area Networks (LANs), video and data distribution (eg. CATV, SONET), optically fed wireless systems and remoting of radar, could benefit from it. However the opto-electronic interconnects are major bottlenecks in such systems. The HBT operating as a three-terminal photodetector is potentially the best solution for optoelectronic integrated receivers. It is compatible with post- detection electronics requiring no matching circuits which reduces parasitics and is capable of providing simultaneous gain and amplification at high frequencies. It also requires small bias voltages which leads to lower power consumption, a very attractive characteristic for monolithic circuits. This work presents a comprehensive theoretical and experimental analysis of the HBT under illumination. The study covers static, dynamic and noise properties of these devices when working as photodetectors. Other types of transistors are also investigated such as the MESFET and the HEMT. Experimental results for the three types of transistors are compared to currently used photodiodes (PIN and MSMs). A new HBT photodetector, the optical-HBT, is proposed, implemented and characterized. The new design enhances the sensitivity of conventional HBTs without degrading bandwidth. The optical-HBT is fully compatible with existing electronics, has low power consumption and provides large gain and bandwidth simultaneously.

de Barros, Luiz Eugenio Monteiro, Jr.

1997-11-01

470

Flicker Noise in Bilayer Graphene Transistors  

NASA Astrophysics Data System (ADS)

We present the 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 fabricated transistors was around 10 V. The noise spectra at frequencies above 10 - 100 Hz were of the 1/f - type with the spectral density on the order of 10E-23 - 10E-22 A2/Hz at the frequency of 1 kHz. The deviation from the 1/f spectrum at the frequencies below 10 -100 Hz indicates that the noise is of the carrier - number fluctuation origin due to the carrier trapping by defects. The Hooge parameter of 10E-4 was extracted for this type of devices. The gate dependence of the noise spectral density suggests that the noise is dominated by the contributions from the ungated part of the device channel and by the contacts. The obtained results are important for graphene electronic applications.

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

2009-03-01

471

Nonlinear Oscillations in a Unijunction Transistor Circuit  

NASA Astrophysics Data System (ADS)

Many interesting nonlinear behaviors have been studied in distributed (glow-discharge and Q-machine plasmas) and non-distributed (nonlinear electronic oscillators) nonlinear systems that can be modeled by the van der Pol equation.footnotetextPhys. Plasmas 3, 4421 (1996).^,footnotetextGeophys. Res. Lett., 21, 1011 (1994).^,footnotetextPhys. Rev. A 44, 6877 (1991). This work describes an experimental, theoretical and computational investigation of two nonlinear electronic oscillators which have a unijunction transistor as a nonlinear element. The circuits that are examined in this paper are a sine wave oscillator and a relaxation oscillator. The functioning of the unijunction transistor is explained in detail. A full derivation of the differential equation describing the sine wave oscillator is made, and the results of numerical simulations based on this differential equation are compared to experimental data. Descriptions and explanations of two types of non-autonomous (driven) phenomena, entrainment and periodic pulling will be given. [1] Present affiliation: Univ. of Notre Dame, [2] Present affiliation: SUNY Oswego

Christopher, Steven; Zielinski, John; Koepke, Mark

2012-10-01

472

A low-power wide range transimpedance amplifier for biochemical sensing.  

PubMed

This paper presents a novel low voltage and low power transimpedance amplifier for amperometric potentiostats. The power is optimized by having three different gain settings for different current ranges, which can be programmed with a biasing current. The voltage ranges have been optimized by using FGMOS transistors in a second voltage amplification stage that simultaneously allow for offset calibration as well as independent biasing of the gates. The circuit operates with input currents from 1 pA to 1 microA, with a maximum power supply voltage of 1.5 V and consumes 82.5 nW, 9.825 microW, 47.325 microW for currents varying from (1 pA, 0.25 nA), (0.25 nA, 62.5 nA) and (62.5 nA, 1 microA) respectively. PMID:18002545

Rodriguez-Villegas, Esther

2007-01-01

473

A 0.09 ?W low power front-end biopotential amplifier for biosignal recording.  

PubMed

This work presents a biopotential front-end amplifier in which the MOS transistors are biased in subthreshold region with a supply voltage and current of 0.4-0.8 V and 0.23-1.86 ?A, respectively, to reduce the system power. Flicker noise is then removed using a chopping technique, and differential interference produced by electrode impedance imbalance is suppressed using a Gm-C filter. Additionally, the circuit is fabricated using TSMC 0.18 ?m CMOS technology with a core area of 0.77 × 0.36 mm². With a minimum supply voltage of 0.4 V, the measured SNR and power consumption of the proposed IC chip are 54.1 dB and 0.09?W, respectively. PMID:23853237

Tseng, Yuhwai; Ho, Yingchieh; Kao, Shuoting; Su, Chauchin

2012-10-01

474

Polycrystalline silicon conductivity modulated thin film transistors  

NASA Astrophysics Data System (ADS)

Polycrystalline silicon (poly-Si) thin-film transistors (TFTs) on glass has received significant attention for use in large area microelectronic applications. These applications include both niche and large volume applications such as printer drivers, image scanners, active-matrix liquid crystal displays (AMLCDs), electro-luminescent displays, plasma assisted displays, etc. Currently, the leading technology for these applications is amorphous-Si (a-Si) TFT. However, as the information content increases, a-Si technology encounters severe challenges due to its inherent low mobility, high parasitic capacitance, low aperture ratio, and non-compatibility to CMOS process. On the other hand, poly-Si technology offers high mobility, low parasitic capacitance, small size, CMOS compatibility, good stability, and uses the infrastructure of silicon science and technology. Thus, a simple low temperature poly-Si technology which allows large area system integration on panel will be in great demand for future high definition displays. However, it was found that poly-Si material properties vary with its method of preparation, its grain size, its surface roughness, and the nature and distribution of the inter-granular and bulk defects. Therefore, extensive studies are needed to optimize the key parameters such as the off-current, on-current, and breakdown voltage of the devices. These parameters can be optimized by means of material preparation as well as innovative device designs. In this thesis, three TFT structures were invented and fabricated using a simple low temperature poly-Si technology. With these novel structures, pixels, pixel drivers, and analog and digital peripheral circuits can all be built on the same glass substrate. This allows the ultimate goal of display systems on glass to be much more closer to reality. First, a high voltage transistor called the Conductivity Modulated Thin Film Transistor (CMTFT) is presented. Using this structure, the fundamental current pinching problem of the conventional high voltage offset drain TFT is completely eliminated. Experimental results show that the CMTFT can handle three orders of magnitude higher current than that of the conventional offset drain TFT while still providing low leakage current, high breakdown voltage, and fast switching speed. It is very suitable to be used as pixel drivers and high voltage printer drivers. In order to implement efficient pixel transistors and design analog peripheral circuits on glass, a second novel structure called the double-gate Elevated-Channel Thin Film Transistor (ECTFT) is invented. The ECTFT exhibits kink-free IV characteristics and low leakage current compared to the conventional uniform thin- and thick-film devices. Furthermore, the double-gate operation of the device provides much higher output current, high on/off current ratio, and steeper subthreshold slope compared to the uniform film devices. All of these result in efficient pixels and high performance analog devices to be built on glass. Finally, to further optimize the CMTFT using the ECTFT technology, a third novel structure called the double-gate Elevated Channel CMTFT (EC-CMTFT) is fabricated. Combining the advantages of elevated channel and conductivity modulation, the EC-CMTFT has a four times reduction in offset region resistance and a five times larger on/off current ratio compared to the CMTFTs.

Anish, Kumar K. P.

1997-09-01

475

Quasi-optical antenna array amplifiers  

Microsoft Academic Search

Several quasi-optical transmission wave amplifiers are presented: (1) a two-level power-combining PHEMT patch-antenna lens amplifier with 8 dB of absolute power gain at 9.7 GHz used for beamforming and beam-switching; (2) a saturated class-A polarization-preserving 24-MESFET patch array which produces 0.7 Watts at 10 GHz with 21% power-added efficiency; and (3) an X-band 2-stage low-noise CPW PHEMT amplifier cell using

Jon Schoenberg; Tom Mader; Boyd Shaw; Z. B. Popovic

1995-01-01

476

Signal Conditioning Amplifier and Recorder (SCAmpR).  

National Technical Information Service (NTIS)

The Signal Conditioning Amplifier and Recorder (SCAmpR) system is presented. The topics include: (1) System Description; (2) Universal Signal Conditioning Amplifier (USCA); (3) Advanced Data Acquisition System (ADAS); and (4) Signal Conditioning Amplifier...

P. J. Medelius

2002-01-01

477

Ultra-low-voltage floating-gate transconductance amplifiers  

Microsoft Academic Search

Ultra-low-voltage (ULV) floating-gate differential amplifiers are presented. In this paper, we present several different approaches to CMOS ULV amplifier design. Sinh-shaped and tanh-shaped transconductance amplifiers are described. Measured results are provided

YNGVAR BERG; TOR S. LANDE; O. Naess; Henning Gundersen

2001-01-01

478

Top-gated CVD Graphene Transistors with Current Saturation  

PubMed Central

Graphene transistors are of considerable interest for radio frequency (RF) applications. In general, transistors with large transconductance and drain current saturation is desirable for RF performance, which is however nontrivial to achieve in graphene transistors. Here we report high performance top-gated graphene transistors based on chemical vapor deposition (CVD) grown graphene with large transconductance and drain current saturation. The graphene transistors were fabricated with evaporated high dielectric constant material (HfO2) as the top-gate dielectrics. Length scaling studies of the transistors with channel length from 5.6 µm to 100 nm shows that complete current saturation can be achieved in 5.6 µm devices and the saturation characteristics degrade as the channel length shrinks down to 100–300 nm regime. The drain current saturation was primarily attributed to drain bias induced shift of the Dirac points. With the selective deposition of HfO2 gate dielectrics, we have further demonstrated a simple scheme to realize a 300 nm channel length graphene transistors with self-aligned source-drain electrodes to achieve the highest transconductance of 250 µS/µm reported in CVD graphene to date.

Bai, Jingwei; Liao, Lei; Zhou, Hailong; Cheng, Rui; Liu, Lixin; Huang, Yu; Duan, Xiangfeng

2011-01-01

479

Modeling of organic thin film transistors: Effect of contact resistances  

NASA Astrophysics Data System (ADS)

Field effect transistors require an Ohmic source contact and an Ohmic drain contact for ideal operation. In many real situations, however, and specifically in organic devices, the injection of charge carriers from metals into semiconductors can be an inefficient process that is non-Ohmic. This has an adverse impact on the performance of thin film transistors and makes the analysis of electrical measurements a complex task because contact effects need to be disentangled from transistor properties. This paper deals with the effects of non-Ohmic contacts on the modeling of organic transistors and gives specific rules on how to extract the real transistor parameters (mobility, threshold voltage, and contact resistances) using only electrical measurements. The method consists of a differential analysis of the transfer characteristic curves (current versus gate voltage) and exploits the different functional dependences of current on gate voltage which is induced by the presence of contact resistances. This paper fully covers the situations from constant carrier mobility to power law gate-voltage-dependent mobility, from constant contact resistance to gate-voltage-dependent contact resistance, and in the linear and in the saturation regime of the operation of the transistor. It also gives important criteria for the validation of the extracted parameters to assess whether the conditions for the application of the method are fulfilled. Examples of application to organic transistors showing various behaviors are given and discussed.

Natali, Dario; Fumagalli, Luca; Sampietro, Marco

2007-01-01

480

Phased Array Antenna Amplifier Exploratory Development Model.  

National Technical Information Service (NTIS)

This final report describes the design characteristics and test results of a scale model (mechanically steerable) Phase Array Antenna Amplifier. As a result of this development investigation, a design approach for a 1 KW system is presented. This report i...

P. Muscianesi J. Irvine J. Ranghelli

1979-01-01

481

Fluidic Vortex Amplifier for Environmental Control.  

National Technical Information Service (NTIS)

The work focused on a technology that uses a fluidic vortex amplifier for environmental control of industrial enclosures. The basic requirement for environmental control is a flow component that can vary its flow resistance quickly and automatically in re...

S. C. Chang

1987-01-01

482

Undulators for short wavelength FEL amplifiers.  

National Technical Information Service (NTIS)

Issues critical to the design of undulators for use in short wavelength FEL amplifiers, such as attainable on-axis field strength, device compactness, field quality, required magnetic gap, and strong focusing schemes, are discussed. The relative strength ...

R. D. Schlueter

1994-01-01

483

Output Performance of Idealized Microwave Power Amplifiers.  

National Technical Information Service (NTIS)

Output power, efficiency, power dissipation and optimum load resistance expressions for idealized microwave class A and class B power amplifiers are derived based on a waveform analysis. The effects of device transconductance variation with bias and circu...

L. J. Kushner

1989-01-01

484

High Current, Very Wide Band Transconductance Amplifier.  

National Technical Information Service (NTIS)

The present invention relates to high current transconductance amplifiers that are stable over a very wide bandwidth. The invention overcomes current/frequency limitations by utilizing the inherent tendency for paralleled current mirrors to add currents s...

O. Laug

1989-01-01

485

One Kilowatt UHF Power Amplifier Study.  

National Technical Information Service (NTIS)

A study effort was conducted to determine the current state-of-the-art in one kilowatt UHF power amplifiers. Studies and investigations culminated in a final technical report containing a detail performance specification and recommended overall design app...

P. R. Hoffmann

1975-01-01

486

Integrated CMOS amplifier for ENG signal recording.  

PubMed

The development and in vivo test of a fully integrated differential CMOS amplifier, implemented with standard 0.7-microm CMOS technology (one poly, two metals, self aligned twin-well CMOS process) intended to record extracellular neural signals is described. In order to minimize the flicker noise generated by the CMOS circuitry, a chopper technique has been chosen. The fabricated amplifier has a gain of 74 dB, a bandwidth of 3 kHz, an input noise of 6.6 nV/(Hz)0.5, a power dissipation of 1.3 mW, and the active area is 2.7 mm2. An ac coupling has been used to adapt the electrode to the amplifier circuitry for the in vivo testing. Compound muscle action potentials, motor unit action potentials, and compound nerve action potentials have been recorded in acute experiments with rats, in order to validate the amplifier. PMID:15605867

Uranga, A; Navarro, X; Barniol, N

2004-12-01

487

High Bandwidth Differential Amplifier for Shock Experiments  

SciTech Connect

We developed a high bandwidth differential amplifier for gas gun shock experiments. The circuit has a bandwidth up to 1 GHz, and is capable of measuring signals of ?1.5 V with a common mode rejection of 250 V. Conductivity measurements of gas gun targets are measured by flowing high currents through the targets. The voltage is measured across the target using a technique similar to a four-point probe. Because of the design of the current source and load, the target voltage is approximately 250 V relative to ground. Since the expected voltage change in the target is < 1 V, the differential amplifier must have a large common mode rejection. Various amplifying designs are shown, although the increased amplification decreases bandwidth. Bench tests show that the amplifier can withstand significant common mode DC voltage and measure 10 ns, and 50 mV signals.

Ross, P., Tran, V., Chau, R.

2012-10-01

488

High bandwidth differential amplifier for shock experiments.  

PubMed

We developed a high bandwidth differential amplifier for gas gun shock experiments of low-resistance metals. The circuit has a bandwidth up to 1 GHz, and is capable of measuring signals of ?1.5 V with a common mode rejection of 250 V. Conductivity measurements of gas gun targets are measured by flowing high currents through the targets. The voltage is measured across the target using a technique similar to a four-point probe. Because of the design of the current source and load, the target voltage is ?250 V relative to ground. Since the expected voltage change in the target is <1 V, the differential amplifier must have a large common mode rejection. Various amplifying designs are shown, although the increased amplification decreases bandwidth. Bench tests show that the amplifier can withstand significant common mode dc voltage and measure 10 ns, and 50 mV signals. PMID:23126892

Ross, P W; Tran, V; Chau, R

2012-10-01

489

Single-photon transistor in circuit quantum electrodynamics.  

PubMed

We introduce a circuit quantum electrodynamical setup for a "single-photon" transistor. In our approach photons propagate in two open transmission lines that are coupled via two interacting transmon qubits. The interaction is such that no photons are exchanged between the two transmission lines but a single photon in one line can completely block or enable the propagation of photons in the other line. High on-off ratios can be achieved for feasible experimental parameters. Our approach is inherently scalable as all photon pulses can have the same pulse shape and carrier frequency such that output signals of one transistor can be input signals for a consecutive transistor. PMID:23971573

Neumeier, Lukas; Leib, Martin; Hartmann, Michael J

2013-08-06

490

Performance Limits of Monolayer Transition Metal Dichalcogenide Transistors  

NASA Astrophysics Data System (ADS)

The performance limits of monolayer transition metal dichalcogenide transistors are examined with a ballistic MOSFET model. Using ab-initio theory, we calculate the band structures of two-dimensional (2D) transition metal dichalco-genide (MX2). We find the lattice structures of monolayer MX2 remain the same as the bulk MX2. Within the ballistic regime, the performances of monolayer MX2 transistors are better compared to the silicon transistors if thin high-{\\kappa} gate insulator is used. This makes monolayer MX2 promising 2D materials for future nanoelectronic device applications.

Liu, Leitao; Kumar, S. Bala; Ouyang, Yijian; Guo, Jing

2011-09-01

491

Organic transistors in optical displays and microelectronic applications.  

PubMed

Organic thin-film transistors (OTFTs) offer unprecedented opportunities for implementation in a broad range of technological applications spanning from large-volume microelectronics and optical displays to chemical and biological sensors. In this Progress Report, we review the application of organic transistors in the fields of flexible optical displays and microelectronics. The advantages associated with the use of OTFT technology are discussed with primary emphasis on the latest developments in the area of active-matrix electrophoretic and organic light-emitting diode displays based on OTFT backplanes and on the application of organic transistors in microelectronics including digital and analog circuits. PMID:20533415

Gelinck, Gerwin; Heremans, Paul; Nomoto, Kazumasa; Anthopoulos, Thomas D

2010-09-01

492

Complementary organic field effect transistors by ultraviolet dielectric interface modification  

NASA Astrophysics Data System (ADS)

The realization of p- and n-type pentacene organic field effect transistors and an organic inverter stage is reported based on selective ultraviolet (UV) modification of the polymer dielectric in air. Apart from the UV radiation treatment, the device structures are identical. The achieved field effect carrier mobilities for both transistor types are ~0.1 cm2/V s. Similar performance data for both transistor types as well as an observed low current hysteresis qualify the UV treatment for organic complementary metal oxide semiconductor (O-CMOS) technology. The realized O-CMOS inverter exhibits stable operation below its supply voltage, as well as a gain of 17.

Benson, Niels; Schidleja, Martin; Melzer, Christian; Schmechel, Roland; von Seggern, Heinz

2006-10-01

493

Charge control in a model biphenyl molecular transistor.  

PubMed

We study charge control in a gated 4,4'-biphenyl diradical molecular transistor using ab initio density functional theory calculations. I-V curves and intrinsic gate capacitances were derived. We find charge control in this transistor to be strongly affected by polarization of the sigma-states of the molecule, leading to strong electrostatic coupling of the internal potentials to the source and drain electrodes, and relatively weak coupling to the gate. We suggest that this spatially dependent and anisotropic polarization is an essential element in the operation of molecular transistors. PMID:15884895

Lang, Norton D; Solomon, Paul M

2005-05-01

494

Proton and gamma ray induced gain degradation in bipolar transistor  

NASA Astrophysics Data System (ADS)

This paper describes the results of the effect of 24 MeV proton and (CO)-C-60 gamma-irradiation on the collector characteristic., and forward current gain of commercial bipolar transistor (npn 2N2219A). The transistor has been exposed to these radiations in the biased condition and the collector characteristics and forward current gain have been measured as a function of proton fluence and gamma-dose. The observation is that both the proton and gamma-irradiation induce significant gain degradation in the transistor. The results are discussed in terms of displacement damage produced by energetic protons and gamma-radiation in the bulk of the semiconductor.

Kulkarni, S. R.; Sarma, A.; Joshi, G. R.; Ravindra, M.; Damle, R.

2003-09-01

495

Nanoporous alumina wire templates for surrounding-gate nanowire transistors  

NASA Astrophysics Data System (ADS)

Aluminium wires are electrochemically sculptured into bi-directional templates for the templated growth and contacting of nanowires as three terminal devices. The use of this nanostructured template is demonstrated by a ZnO nanowire surrounding-gate field-effect transistor. This bottom-up approach to a 3D nanowire transistor is unique in that it can be almost entirely fabricated in a beaker using aqueous, room temperature electrochemistry. The fabrication procedures and preliminary device characteristics of this new approach to nanowire transistors are shown.

Wade, Travis L.; Hoffer, Xavier; Dughaim Mohammed, Al; Dayen, Jean-François; Pribat, Didier; Wegrowe, Jean-Eric

2007-03-01

496

Current status of ferroelectric-gate Si transistors and challenge to ferroelectric-gate CNT transistors  

Microsoft Academic Search

Current status of ferroelectric-gate FETs (field effect transistors) is reviewed. First, characteristics of Si FETs with MFIS (metal–ferroelectric–insulator–semiconductor) gate structures are discussed. It has been shown that the data retention characteristics of ferroelectric-gate FETs are much improved by use of HfO2-based buffer layers which are inserted between the ferroelectric-gate film and Si substrate for preventing inter-diffusion of constituent elements. Then,

Hiroshi Ishiwara

2009-01-01

497

Gigahertz low noise CMOS transimpedance amplifier  

Microsoft Academic Search

A new class of low noise CMOS common gate transimpedance amplifier is described. What is novel about the design is the total isolation of the photodiode capacitance from determining the -3 dB bandwidth. HSPICE simulations of this amplifier were conducted using the Tritech 0.6 ?m CMOS process. Simulated performance gives 2 GHz bandwidth, 1.13 k? transimpedance gain and very low

S. M. Park; C. Toumazou

1997-01-01

498

Primer on the Lock-in Amplifier  

NSDL National Science Digital Library

This is an experiment designed to measure the resistance of copper and gold nanowires using a lock-in amplifier. Students learn: 1. about different types of noise, 2. the principles of phase-sensitive techniques, 3. to extract signals buried in noise using a lock-in amplifier, 4. to operate optical chopper to measure weak optical signals modulated at a certain frequency. 4. to measure the minute resistance of a conducting nanowires.

Farooq, Sidra; Salman, Rabiya; Zia, Wasif; Hassan, Umer; Anwar, Muhammad S.

2012-02-10

499

Recent progress in semiconductor laser amplifiers  

Microsoft Academic Search

Recent progress in semiconductor laser amplifiers (SLAs), mainly GaInAsP traveling-wave semiconductor laser amplifiers (TWAs) for use in optical fiber transmission systems, is discussed. The status of antireflection coating on laser-diode facets which are indispensable for TWAs is discussed. Reported data on small-signal gain, signal-gain saturation, and noise are summarized and discussed in relation to active-layer parameters. Common amplification using SLAs

Tadashi Saitoh; Takaaki Mukai

1988-01-01

500

Amplifiers and Lasers in PCF Configurations  

Microsoft Academic Search

In this paper we will present an overview of the use \\u000aof photonic crystal fibers as fiber amplifiers. We \\u000awill describe the basic concepts of optical \\u000aamplification, and how to do numerical modelling of \\u000asuch components. We will then identify advantages \\u000aand disadvantages of amplifiers based on PCF\\u000atechnology compared to conventional fibers, and then \\u000ago into greater detail on

Kristian Hougaard; Frederik D. Nielsen

2004-01-01