基于小信号S参数的MOSFET射频功率放大器设计

介绍了如何利用场效应管的小信号散射(S)参数设计射频功率放大器,并采用此设计方法,选用场效应管,设计了一种工作在160 MHz频段的金属氧化物半导体场效应管(MOSFET)功率放大器.在工作频段内,功率放大器增益大于23 dB,输入端口的匹配网络的回波损耗S11优于-19 dB.实例证明:该设计方法仿真简单,易于实现,具有重要的工程应用价值.     

射频开关模块的设计与应用

开关系统是整个自动测试系统的核心,其性能直接影响自动测试系统的指标和功能.射频开关作为开关系统的组成部分之一,在开关系统中有其重要应用.本文主要介绍了一种基于VXI总线射频开关模块的设计,包括其电路组成,PCB板上射频信号线的特性阻抗.最后,介绍了射频开关模块在自动测试系统中的应用.     

X波段移相器中低弹性系数RF-MEMS开关的研究

讨论了一种应用于X波段开关线型移相器中的新型低弹性系数RF-MEMS静电式开关的设计.通过对多臂梁式结构RF-MEMS开关的力学性能和电学性能进行有限元仿真和优化,开关的弹性系数为17.63N/m.在10GHz的工作频率下,此RF-MEMS开关驱动电压为36.5V,移相器的插入损耗小于9dB.     

一种平板式MEMSRF射频开关的设计

介绍了一种实用的平板电容式MEMSRF射频开关。研究了外加驱动电压与由此所引起的极板间距和极板受力变化之间的非线性关系,提出了一种有效的基于有限元的设计分析方法,在此基础上设计了相应的MEMS加工工艺流程,并给出了具体的MEMS工艺。     

45nm MOSFET射频小信号噪声等效电路建模直接提取方法

针对45 nm MOSFET射频等效电路建模和参数提取技术进行了研究,在精确地提取了射频小信号模型参数之后,基于双端口网络的噪声相关矩阵和多端口噪声理论,使用本征电路的噪声电流源嵌入有噪声贡献的元件,从而分析推导出射频噪声参数模型,并与商用的45 nm CMOS射频测量值相对比,在相应的频段内显示出很好的正确性。     

多路开关变位信号智能采集系统的设计

多路开关变位信号智能采集系统的设计阎保定，郭跟成ＤｅｓｉｇｎｏｆＩｎｔｅｌｌｉｇｅｎｔＣｏｌｌｅｃｔＳｙｓｔｅｍｆｏｒＶａｒｉａｂｌｅＤｅｆｌｅｃｔｉｏｎＳｉｇｎａｌｂｙＭｕｌｔｉｗａｙＳｗｉｔｃｈ￥ＹａｎＢａｏｄｉｎｇ；ＧｕｏＧｅｎｃｈｅｎｇ在许多...     

射频和微波开关测试系统基础

本文讨论射频和微波测试中如何提高测试吞吐量，并降低测试成本的方法及其测试系统基础。     

应用于移动手机的SOI线性射频功率放大器的设计

主要研究采用IBM公司SOI 0.18μm CMOS工艺设计应用于1.95 GHz WCDMA发射机的全集成线性功率放大器的设计方法。电路采用三级AB类放大器级联结构,模拟结果显示,在工作电压为2.5 V的情况下,CMOS射频功率放大器工作稳定,1 d B压缩点输出功率约为30 d Bm,增益约为28 d B,最大功率增加效率(PAE)约为42%。     

扭转臂杠杆式MEMS膜开关的分析

为解决现有的MEMS微波开关的激励电压太高、微连接和膜开关的击穿电压等问题,提出了一种独特结构的MEMS微波开关—扭转臂杠杆式膜开关,并对其进行了理论分析,用conventorware和ADS(ad vanceddesignsystem)软件进行了仿真。由于利用了膜结构以及扭转臂和杠杆的原理,这种独特的MEMS微波开关激励电压比较低、隔离度较高、插入损耗比较低、稳定性好。     

交流电源对DCS系统直流开关信号的影响及对策

以DCS系统改造为背景,提出在多芯电缆中存在的交流和直流信号之间是否存在影响的问题.通过两种不同形式的回路实验,得出交流电源对DCS系统直流开关信号影响不明显,并提出为避免现场直流开关信号受到干扰的对策.     

Analysis of a novel RF MEMS switch using different meander techniques

In this paper, two types of RF MEMS switches namely step structure and Normal beam structure are designed and analyzed using different meander techniques. Three techniques namely plus, zigzag and three-square meander were used to lower the pull-in voltage. The actuating beam is designed with the rectangular perforations affects the performance of a switch by lowering the pull-in voltage, switching speed and results in better isolation. In this paper a comparative analysis is done for all three meander techniques with and without perforations on the beam. Total six structures have been designed with the combination three meanders and two different beam structures. The proposed stepdown structure exhibits high performance characteristics with a very low pull-in voltage of 1.2 V having an airgap of 0.8 µm between the actuation electrodes. The gold is used as beam material and HfO₂ as the dielectric material such that the upstate and downstate capacitance is seen as 1.02 fF and 49 fF. The FEM analysis is done to calculate the spring constant and thereby the pull-in voltage and behavior of the switch is studied with various parameters. The switch with a step structure and three-square meander configuration has shown best performance of all by requiring a pull-in voltage of 1.2 V and lower switching time of 0.2 µs. The proposed switch also exhibits good RF performance characteristics with an insertion loss below − 0.07 dB and return loss below − 60 dB over the frequency range of 1–40 GHz. At 28 GHz a high isolation of − 68 dB is exhibited.

     

Analysis of uniform structured RF MEMS switch with different uniform and non-uniform meandering techniques

Microsystem Technologies - This paper mainly focuses on the investigation of different meandering techniques for the MEMS RF shunt capacitive switch. It involves three meandering techniques for the...     

悬臂梁接触式RF MEMS开关的关键工艺研究

采用厚度为2μm的Au制作成共平面波导（CPW）、聚酰亚胺作为牺牲层、PECVD法淀积Si3N4薄膜作为悬臂梁,制作成悬臂梁接触式RF MEMS开关。着重对开关的关键工艺-CPV的Au剥离工艺和悬臂梁制作工艺进行研究,讨论了工艺中存在的问题及其解决方法。通过实验获得较佳的工艺参数,并制作出驱动电压为12-20V的悬臂梁接触式RF MEMS开关。     

Design and analysis of asymmetric structure capacitive RF MEMS shunt switch

Microsystem Technologies - This paper deals with the study of shunt capacitive RF switches. Comparative study is done on non-uniform designed structures, which are simulated using finite element...     

Analysis of RF MEMS shunt capacitive switch with uniform and non-uniform meanders

Microsystem Technologies - This paper reports on electromechanical, switching time and performance analysis of capacitive shunt RF MEMS switch with uniform and non-uniform meanders. The MEMS switch...     

Design of a novel step structure RF MEMS switch for K-band applications

Microsystem Technologies - In this paper, we have design a proposed step structure RF MEMS switch for K-band applications. The non-uniform meander structure is implemented for both optimized and...     

发展中的RF MEMS开关技术

从驱动方式和机械结构的角度介绍了不同的RF MEMS开关类型,分析了各类MEMS开关的性能及优缺点,分析了MEMS开关在制作和发展中面临的牺牲层技术、封装技术、可靠性问题等关键技术和问题,介绍了MEMS开关的发展现状及其在组件级和系统级的应用,以及对MEMS开关技术的展望。     

A low-voltage lateral MEMS switch with high RF performance

MEMS switches are one of the most promising future micromachined products that have attracted numerous research efforts in recent years. The majority of MEMS switches reported to date employ electrostatic actuation, which requires large actuation voltages. Few are lateral relays and those often require nonstandard post process, and none of them is intended for high-frequency applications. We have developed an electrothermally actuated lateral-contact microrelay for RF applications. It is designed and fabricated on both low-resistivity and high-resistivity silicon substrate using surface micromachining techniques. The microrelay utilizing the parallel six-beam actuator requires an actuation voltage of 2.5-3.5 V. Time response is measured to be 300 /spl mu/s and maximum operating frequency is 2.1 kHz. The RF signal line has a current handling capability of approximately 50 mA. The microrelay's power consumption is in the range of 60-100 mW. The lateral contact mechanism of the microrelay provides a high RF performance. The microrelay has an off-state isolation of -20 dB at 40 GHz and an insertion loss of -0.1 dB up to 50 GHz. The simplicity of this 4-mask fabrication process enables the possibility of integrating the microrelay with other passive RF MEMS components.     

Optimality conditions and algorithms for parameter design problems with two-level structure

We consider the parameter design problem for a central system coordinating plural semiautonomous subsystems each of which optimizes its own objective under the given parameter from the center. The center makes a decision of the parameter values to be assigned to the subsystems so as to optimize its objective, considering the values of optimized subsystems' performances. Such a parameter design problem is formulated in the framework of a two-level planning problem and becomes an optimization problem including optimal-value functions, and accordingly, a nondifferentiable optimization problem. In this paper, based on Gauvin's studies concerned with the directional derivatives of optimal-value functions, we derive the necessary conditions for the parameter design problem by means of a new theorem of the alternative. The results obtained here are slightly different from the Kuhn-Tucker-like conditions, and are adapted to the structure of the problem. As the computational method for our problem, we propose applying an existing generalized gradient algorithm called the "bundle method" in a class of nondifferentiable optimization methods, and also show a numerical example.     

Analysis of electromagnetic interference of a capacitive RF MEMS switch during switching

Based on the dynamic model of the membrane bridge for a capacitive RF MEMS switch, the switching process may be divided into four stages: the charging of the switch capacitor, pull-down of the bridge, discharging of the switch capacitor, and the release of the bridge. A model for the electromagnetic field produced in each stage is developed by using Maxwell equations. In the charging stage and the discharging stage, the value of the magnetic field produced is invariable (6, 20.7 A/m) and the electric field increases or decreases linearly. But in the pull-down stage the electromagnetic field produced is a pulse field (maximum value is 6.05 A/m). In the release stage, the magnitude of the electromagnetic field is too small to be considered. The electromagnetic field will induce noise on the RF signal in the CPW during switching. Finally, the electromagnetic field model is verified by numerical simulations. The electromagnetic field model and analysis presented here are valuable to optimize the design in order to minimize the electromagnetic interference.