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排序方式: 共有234条查询结果,搜索用时 15 毫秒
11.
M. Kameche 《Journal of Computational Electronics》2007,6(4):421-424
This paper describes the temperature dependence of the drain current and the drain temperature in dual-gate GaAs MESFETs.
The model presented, effectively couples together the effects of the operating temperature and the polarization voltages on
the electron temperature and the drain current. This offers improved accuracy over existing models by considering a nonlinear
field-dependent diffusivity-to-mobility ratio. Two-dimensional numerical simulation is used to describe significant physics
in the characteristics for 0.5 μm gates GaAs DGMESFET. 相似文献
13.
14.
Masayoshi Umeno Takashi Egawa Hiroyasu Ishikawa 《Materials Science in Semiconductor Processing》2001,4(6)
A recessed gate AlGaN/GaN high-electron mobility transistor (HEMT) on sapphire (0 0 0 1), a GaN metal-semiconductor field-effect transistor (MESFET) and an InGaN multiple-quantum well green light-emitting diode (LED) on Si (1 1 1) substrates have been grown by metalorganic chemical vapor deposition. The AlGaN/GaN intermediate layers have been used for the growth of GaN MESFET and LED on Si substrates. A two-dimensional electron gas mobility as high as 9260 cm2/V s with a sheet carrier density of 4.8×1012 cm−2 was measured at 4.6 K for the AlGaN/GaN heterostructure on the sapphire substrate. The recessed gate device on sapphire showed a maximum extrinsic transconductance of 146 mS/mm and a drain–source current of 900 mA/mm for the AlGaN/GaN HEMT with a gate length of 2.1 μm at 25°C. The GaN MESFET on Si showed a maximum extrinsic transconductance of 25 mS/mm and a drain–source current of 169 mA/mm with a complete pinch-off for the 2.5-μm-gate length. The LED on Si exhibited an operating voltage of 18 V, a series resistance of 300 Ω, an optical output power of 10 μW and a peak emission wavelength of 505 nm with a full-width at half-maximum of 33 nm at 20 mA drive current. 相似文献
15.
Ho-Young Cha Y. C. Choi R. M. Thompson V. Kaper J. R. Shealy L. F. Eastman M. G. Spencer 《Journal of Electronic Materials》2004,33(8):908-911
The SiC metal-semiconductor field-effect transistors (MESFETs) have been reported to have current instability and strong dispersion
caused by trapping phenomena at the surface and in the substrate, which degrade direct-current (DC) and radio-frequency (RF)
performance. This paper illustrates the change in electrical characteristics of SiC MESFETs after Si3N4 passivation. Because of a reduction of surface trapping effects, Si3N4 passivation can diminish current collapse under pulsed DC conditions, increasing the RF power performance. The reduction
of surface trapping effects is verified by the change in the ratio of the drain current to the gate current under pinch-off
conditions. 相似文献
16.
Rong-Ting Huang Dumrong Kasemset N. Nouri C. Colvard D. Ackley 《Journal of Electronic Materials》1989,18(5):603-609
A unique multi-wafer OMVPE reactor with capability to produce atomic-layer abrupt-ness is demonstrated. Uniform GaAs and AlGaAs epitaxial layers were grown on four two-inch wafers or one three- or four-inch wafer. Thickness variation across a three-inch wafer was less than ±2%, while the variation of Al solid composition was less than ±1%. Multiple AlGaAs/GaAs quantum wells ranging in size from 10Å to 140Å were grown with heterointerface roughness less than one monolayer. The electrical properties of HEMT device were studied. Variations of sheet carrier concentration and electron mobility were ±6% and ±5% respectively across a three-inch wafer. The carrier con-centration profile, mobility spectrum and device characteristics of DH-HEMT are also presented. These results indicate that this OMVPE reactor can grow good device struc-tures for microwave and millimeter-wave power device applications. 相似文献
17.
Using the nonlinear Volterra series representation, analytical expressions for the third-order intermodulation distortion power and intercept point for a MESFET small-signal amplifier are derived when its equivalent circuit is bilateral and includes the gate-to-drain capacitance (Cgd) explicitly as a nonlinear element. Previously developed analytical expressions treated Cgd as a linear element or incorporated it as a part of gate-to-source and drain-to-source capacitances (Cgs and Cds). These new analytical expressions are then compared with experimental data and good agreement is obtained. The analytical expressions are also used to study the variation of intermodulation distortion with input power and frequency, and the effect of the individual nonlinear elements in the MESFET’s equivalent circuit. 相似文献
18.
RF wideband power amplifiers are desirable as they will reduce equipment, power consumption and operating cost for the RF communication infrastructure. For decades, the realization of single-stage broadband power amplifier has posed a significant challenge due to the electrical and thermal limitations of GaAs transistor technology. Silicon carbide (SiC) MESFET technology is a strong contender for such applications due to its superior properties. In particular, its high impedance reduces mismatch commonly encountered in such power amplifier.In this work, design of wideband hybrid single-stage power amplifier using a commercial 4H-SiC MESFET CRF24010 from Cree Inc is presented. The amplifier has been designed and fabricated for operating frequencies 650-1800 MHz, which is equivalent to more than 90% bandwidth, compared to only 3-4% bandwidth achievable using GaAs technology. 相似文献
19.
Z. Ghanian A. Abdipour A. Ghorbani 《Analog Integrated Circuits and Signal Processing》2006,49(2):213-223
A VCO in S frequency band is designed by using nonlinear technique based on large signal model of semiconductor devices. The
nonlinear circuit of the VCO is analyzed by a novel analytical approach of harmonic balance method as an autonomous circuit,
and with fulfilling the stability condition of the network, the output specifications are determined. This proposed nonlinear
approach for determining of the frequency and amplitude stability is also based on harmonic balance method. The results of
the analysis are compared with those of measurements. The comparison shows good agreement between results of this analytical
approach and the measurements.
Zahra Ghanian was born in Tehran, Iran, in 1975. She received the B.Sc. degree in electrical engineering from Sharif University of Technology,
Tehran, Iran, in 1998, and the M.Sc. degree from the Amirkabir University of Technology, Tehran, Iran, in 2001. Since 2000,
she has been involved in several research and engineering projects at the Amirkabir University of Technology, Iran Telecommunications
Research Center (ITRC) and Niroo Research Institute (NRI). Her main areas of interest are design, simulation and analysis
of circuits for Microwave, Millimeter wave and Wireless applications.
Abdolali Abdipour was born in Iran in 1966. He obtained his B.Sc. in Electrical Engineering from Tehran University, Tehran, Iran in 1989, and
the M.Sc. in Electronics from Limoges University, Limoges, France in 1992. Then he achieved his PhD degree in Electronic Engineering
from Paris XI University, Paris, France in March 1996. His research areas include wireless communication systems (RF Technology
and Transceivers), RF/Microwave/mm-wave circuit and system design, E & M modeling of active devices and circuits, high frequency
electronics (signal and noise), nonlinear modeling and analysis of microwave devices and circuits. He has published over 80
papers in the refereed journals and international conferences. He authored two books “Noise in Electronic Communication: Modeling, Analysis and measurement” and “Transmission Lines” (in Persian). He is currently an associate professor of Electrical Engineering Department at Amirkabir University of Technology
(Tehran Polytechnic), Tehran, Iran.
Ayaz Ghorbani received PG diploma, m. Phiel and PhD degrees from the university of Bradford U.K. in 1984, 1985 and 1987 respectively in
the area of electrical and communication engineering. From 1987 up to now he has been teaching various courses in the department
of electrical engineering at university of Amirkabir (Tehran poly technique) Tehran, Iran. In 1987 he was awarded John Robertshaw
Travel Award to visit a number of research establishments in the United States of America from Bradford University, and in
1990 he was also awarded U.R.S.I. Young Scientists Award at general assembly of the URSI, Prague, Czech Republic. In 2004
he was in Bradford University for one year as a research visitor where he obtained post doctorate degree. Dr. Ghorbani is
author and coauthor of more than seventy papers in conferences as well as scientific journals. 相似文献
20.
运用双指数函数模型方法分析了影响 MESFET的 Ti Pt Au-Ga As肖特基势垒结特性的各种因素及各因素间的关系 ,编制了 MESFET肖特基势垒结结参数提取和 I-V曲线拟合软件 ,实现了通过栅源正向 I-V实验数据提取反映肖特基势垒结特性的六个结参数和得到相应结参数下的理论数据 ,与实验数据吻合良好。分析了影响肖特基势垒结 I-V曲线分布的因素 ,提出了进行器件特性、参数稳定性与可靠性研究和定量分析 MESFET肖特基势垒结质量的新方法 相似文献