Analysis of a Microwave FET Oscillator Using an Efficient Computer Model for the Device

This paper presents a time domain analysis of a microwave 10-GHz FET oscillator, which employs a practical and efficient computer model for the FET. Good agreement is demonstrated between the predicted and measured performance. A sensitivity analysis of the circuit is performed with respect to some of the FET parameters. This is useful information to estimate variation in production.     

Performance and Design of Microwave FET Harmonic Generators

Experimental measurements of the power gain of a 4- to 8-GHz frequency doubler, employing a single-gate GaAs MESFET device and a microstrip circuit, are reported. The measured performance provides design guidelines, and is explained in terms of FET characteristics. In particular, the multiplication gain is largest when the FET is biased near pinchoff.     

Performance Simulation of a Microwave Micro-Electromechanical System Shunt Switch Using Chatoyant

In this paper we demonstrate the capabilities of our mixed-signal, multi-domain system level simulation tool, Chatoyant, to model and simulate an RF MEMS shunt switch. We verify our mechanical simulations and analysis by comparison to results from commercial simulation packages, ANSYS and CoventorWare. We show that our modeling accuracy and simulation speed are comparable to these commercial tools for specific analysis. We conclude by showing the unique capabilities of a system tool based on a modular hierarchal approach that allows one to model not only the individual components of the system but also the subtle interactions resulting in specific system behaviors.Michael Bails received his B.A. in Economics from the University of Vermont in 1995 and a B.S. in Electrical Engineering from the University of Pittsburgh in 2002 (cum laude). He worked as an undergraduate researcher in optical MEMS for Benchmark Photonics, a Pittsburgh-based start-up company from 2001 to 2002. Mr. Bails is currently pursuing his M.S. in the Department of Electrical and Computer Engineering at the University of Pittsburgh, where he is a recipient of the Rath Fellowship. His interests are in MEMS modeling with an emphasis on statistical process variations. Mr. Bails is a student member of IEEE.José A. Martínez is an Electrical Engineering Ph.D. student at the University of Pittsburgh. He received his MS from the University of Pittsburgh (2000) in Electrical Engineering. He received the BS (magna cum laude) in Electrical Engineering from the Universidad de Oriente (UDO), Venezuela, in 1993. Mr. Martínez was granted the José Feliz Rivas’ medal for high academic achievement by the Venezuelan government (1993), and scholarships by the Venezuelan Fundayacucho Society (1993) and CONICIT-UDO (1994) institution. Since 1997 he has been working in the Optoelectronic computing group at the University of Pittsburgh. His research interests include behavioral simulation, reduction order techniques, modeling of MEMs and OMEMs, CAD, VLSI and computer architecture. Mr. Martínez is a member of IEEE/LEOS, and OSA.Steven P. Levitan is the John A. Jurenko Professor of Computer Engineering in the Department of Electrical and Computer Engineering. He received the B.S. degree from Case Western Reserve University in 1972. From 1972 to 1977 he worked for Xylogic Systems designing hardware for computerized text processing systems. He received his M.S. and Ph.D. in Computer Science from the University of Massachusetts, Amherst. During that time he also worked for Digital Equipment Corporation, and Viewlogic Systems, as a consultant in HDL simulation and synthesis. He was an Assistant Professor from 1984 to 1986 in the Electrical and Computer Engineering Department at the University of Massachusetts. In 1987, Dr. Levitan joined the Electrical Engineering faculty at the University of Pittsburgh where he holds a joint appointment in the Department of Computer Science. He is Past Chair of the ACM Special Interest Group on Design Automation (SIGDA). He was awarded the ACM/SIGDA Distinguished Service Award for over a decade of service to ACM/SIGDA and the EDA Industry in 2002. He is on the technical advisory board for The Technology Collaborative. He is a senior member of the IEEE/Computer Society and a member of the Optical Society of America, the Association for Computing Machinery, and the International Society for Optical Engineering. He is a member of the ACM/IEEE Design Automation Conference Executive Committee.Jason Boles received the B.S. degree in computer engineering from the University of Pittsburgh, Pittsburgh, PA, in 2001, where he is currently pursuing the M.S. degree in electrical engineering. His research interests include hardware acceleration techniques for simulation, system level modeling, computer-aided design (CAD), as well as systems-on-chip design and verification. Mr. Boles is a student member of IEEE.Ilya V. Avdeev is currently with ANSYS, Inc (Canonsburg, PA). He received his B.S. and M.S. degrees both in mechanical engineering from St. Petersburg State Polytechnical University (Russia) in 1997 and 1999 respectively. He received his Ph.D. in mechanical engineering from the University of Pittsburgh in 2003. His dissertation was on modeling strongly-coupled MEMS. He has been an inaugural John Swanson Doctoral Fellow and was awarded numerous scholarships and personal grants during his undergraduate and graduate studies. His research interests include mathematical modeling of coupled-field effects, new finite element techniques and methods, design and simulation of MEMS/NEMS, and acoustics. He is a member of ASME and IEEE.Michael R. Lovell is the Associate Dean for Research and an Associate Professor of Industrial and Mechanical Engineering in the School of Engineering at the University of Pittsburgh. Dr. Lovell received his PhD in Mechanical Engineering in 1994 from the University of Pittsburgh. He joined the Mechanical Engineering Department at Pittsburgh in January of 2000 after three years of service as an Assistant Professor at the University of Kentucky and four years of service as a senior development engineer at ANSYS Inc. Professor Lovell is a W. K. Whiteford Endowed Faculty Fellow, has served as the Executive Director of the Swanson Center for Product Innovation since May of 2000, and has been the Director of the Swanson Institute for Technical Excellence since September of 2002. Among his accomplishments, Professor Lovell is a recipient of the NSF CAREER award (1997), the SME Outstanding Young Manufacturing Engineer Award (1999), and won the FAG Outstanding International Publication on Bearings (1998). Dr. Lovell’s primary research interests are in the areas of tribology, advanced computation, and micro and nano systems.Donald M. Chiarulli, Professor of Computer Science. Dr. Chiarulli received his BS degree (Physics, 1976) from Louisiana State University, MSc (Computer Science, 1979) from Virginia Polytechnic Institute, and PhD (Computer Science, 1986) from Louisiana State University. He was an Instructor/Research Associate at LSU from 1979 to 1986, and has been at the University of Pittsburgh since 1986. Dr. Chiarulli’s research interests are in photonic and optoelectronic computing systems architecture. Dr Chiarulli’s research has been recognized with Best Paper Awards at the International Conference on Neural Networks (ICNN-98) and the Design Automation Conference (DAC-00). He is also the co-inventor on three patents relating to computing systems and optoelectronics. He has served on the technical program committees of numerous conferences for both research and education issues. Dr. Chiarulli serves on the editorial board of the Journal of Parallel and Distributed Systems and is a member of the IEEE. SPIE, and OSA.     

用算术运算法分析多频率激励微波非线性电路

用全频域谐波平衡法的算术运算法分析多频率激励下电路的稳态响应，给出了一种新的Ｊａｃｏｂｉａｎ矩阵的构造方法，能分析任意多的频率激励情况。     

应用遗传算法提取GaAs场效应管小信号模型参数

利用阻抗矩阵法求出GaAs场效应管的小信号等效电路S参数,并提出应用遗传算法提取等效电路模型参数.该法具有收敛快速、精确度高的特点,使各个模型参数均能得到较为精确快速的提取.     

S频段大功率振荡用砷化镓场效应晶体管的微波性能

对WC76型S频段大功率振荡用砷化镓场效应晶体管的微波性能作了介绍。文中给出了测试振荡器的设计。测试结果表明,WC76型振荡管在s频段的微波性能良好,振荡频率在3GHz左右时,输出功率可达3.5w,直流—射频转换效率可达44％,而且在2～4GHz的整个S频段均能满意地工作。     

微波FET有源电感的分析

提出用FET实现四种高性能的微波有源电感基本电路结构，通过分析各个电路的特性表明，这四个有源电感均是低损耗或无损耗的。另外还选择了其中的一种电路结构，详细分析了FET参数变化对有源电感用抗的影响。     

微波非线性电路全频域谐波平衡分析

本文提出了有关全频域谐波平衡方程的牛顿－拉夫逊迭代求解的一种改进方法。     

聚酰亚胺在微波GaAs FET中的应用

聚酰亚胺是一种高分子聚合物材料。它的组分及结构使其具有比SiO_2等无机介质更优越的介质特性与热特性,且刻蚀方法简便。在微波GaAs FET中作表面钝化、双层布线隔离介质应用时明显提高了器件可靠性,尤其改善了塑料封装器件的防潮性能,简化了FET工艺步骤。     

微波FET宽带放大器综述

本文介绍了当前微波FET宽带放大器发展概况和动向,概括说明目前一些主要宽带放大器的机理、特点和设计方法.     

介质腔稳频FET压控振荡器

本文介绍一种新颖的,用介质腔稳频的压控振荡器,叙述了其电调原理,设计考虑,并给出了实验结果;该振荡器的中心频率f_0=5.415GHz;电调带宽△f≥20MHz(V_0=G～-15v);输出功率p_o≥15mw;频率温度系数T≤3.2ppm/℃;在偏离载频100kHz处的调频相位噪声<-90dBc/Hz,该振荡器性能已满足使用单位的要求。     

Analysis of Noise Upconversion in Microwave FET Oscillators

The upconversion of Iow-frequency noise in microwave FET oscillators is investigated. The theoretical analysis is presented in two forms, a general and a simplified one. The latter version yields closed-form expressions for amplitude and phase noise, which are discussed wfth regard to the physics of the upconversion process. Application of the method is demonstrated with an example.     

Microwave I-Q vector modulator using a simple technique forcompensation of FET parasitics

The analysis and design of an improved technique for the realization of vector modulators using analog reflection-type circuits are presented. The analysis focuses on the detrimental effect that the parasitic elements of the FET variable-resistance elements have on the 360° phase and amplitude control. It is shown that a simple circuit technique can be used to compensate for the parasitic effects and achieve a near-ideal constellation. Compared with the balanced structure, the proposed technique leads to a much smaller circuit area and does not require additional complementary control signals. This makes it better suited to commercial wireless applications where low cost is paramount. Simulation and experimental results for an L-band prototype are presented     

Nonlinear analysis of microwave FET oscillators using Volterraseries

A novel approach for determining the amplitude and frequency of nonlinear FET oscillators is presented. The nonlinear elements of the active device are modeled by the Volterra series method. The frequency and amplitude of oscillation are then calculated by solving two algebraic equations. Experimental results obtained from a constructed oscillator confirm the validity of the theory, the discrepancy between measured and calculated frequency and amplitude values being less than 10%     

微波小信号、多级FET放大器的计算机辅助设计

本文在实频技术的基础上发展了一种微波小信号、多级FET放大器的多判据整体设计方法.编制了分级设计程序OPTF和整体设计程序WOPTF可分别用于微型和中、小型计算机上.设计实例证实了此方法是可行的.     

硅垂直沟道功率场效应管的微波性能

本文旨在介绍一种新型微波功率器件——Si垂直沟道功率场效应管,它能在0.8GHz输出10W,在1GHz输出8W功率;增益和效率分别为9分贝、48%和8分贝、37%.该新器件具有许多双极晶体管所不具备的优点,例如好的线性度,小的交叉调制失真,高的输入阻抗,负的温度系数,高的抗辐射能力以及无二次击穿.因此器件最适合于高频功率线性放大,并可望用于超高频电视发射和微波多路通讯.本文给出器件的伏安特性、电参数、等效电路和电路设计,并同时给出S参数的估算.在克服了一系列器件的本征缺点之后,理论和实验结果指出,采用共栅组态可在高频时获得更高的增益.     

Acquisition and Tracking Performance of a PLL Using a Class of Nonlinear Filters

A class of nonlinear filters was proposed in [1] as an alternative loop filter of a PLL. This paper examines further aspects of the performance of a PLL incorporating such a nonlinear filter. The acquisition performance due to frequency offsets and the steadystate tracking performance in the presence of noise and frequency offsets are analyzed and compared with experimental and simulation results. The noise analysis is based on techniques using the FokkerPlanck equation. The effect of the nonlinearity in the loop filter is approximated using a quasi-linearization approach. A modification to the original nonlinear filter structure is proposed in order to obtain the best noise performance in the presence of frequency offsets. The overall improvement in performance of a PLL with a nonlinear filter is evaluated and compared with a conventional PLL and other methods of improved acquisition performance such as the sweep method. The necessary graphs and formulas are presented for the design of a PLL with a nonlinear filter. The extra available design parameter enables the compromise between acquisition and noise performance to be overcome to a significant degree.     

Simulation of a Multiprocessor Switching System Using Model Aggregation

Multiprocessor systems find wide application in telecommunications. Simulation techniques are often incorporated in the performance analysis of these systems. Simulation models enable an operating system to be represented in detail, e.g., multitasking, message handling, and concurrent processing. This level of detail is useful in evaluating software design. However, the complexity of such models can lead to costly simulations. Aggregation techniques can often be used to reduce model complexity. Aggregation typically involves the representation of only part of the system in detail, i.e., the primary subsystem. The remainder of the system is represented by a simplified composite. Parametric analysis is performed on the primary subsystem. The role of the composite is to introduce interactive effects to the primary subsystem. Aggregation techniques are accurate for certain classes of analytic models. The purpose of this study is to apply aggregation to the simulation model of a multiprocessor switching system. A model for real-time performance evaluation is described. An aggregation technique is derived from basic queueing models. The accuracy of the aggregated model is assessed through the simulation of realistic test cases. The results demonstrate that good accuracy can be obtained with aggregation. Substantial simulation cost savings are also demonstrated.     

星载全极化微波散射计系统仿真与性能分析

本文对全极化微波散射计遥感海面风场的原理及其特点进行研究,建立了星载全极化微波散射计的系统仿真模型.对比了SeaWinds散射计参数下全极化与同极化的风场反演质量,结果表明全极化微波散射计在星下点以及刈幅远端的区域有良好的风场反演性能,并可提升高风速条件下的风场反演精度.最后分析了极化通道隔离度对全极化散射计系统性能的影响.