Ka波段0/Π MEMS移相器

报道了一种Ka波段实时延MEMS移相器芯片。该移相器基于开关线式移相器设计原理,集成了4个MEMS三端口直接接触式毫米波开关单元,使用共面波导(CPW)传输线,利用阶梯阻抗的方式实现传输线拐角和CPW空气桥结构的传输线阻抗匹配。芯片采用RF MEMS表面牺牲层工艺制作在400μm厚的高阻硅衬底上,面积为1.4 mm×2.8 mm。测试显示,在34~36 GHz频率范围内,相移误差3.2°,插入损耗2 dB,反射损耗小于-15 dB。     

一个DC-32GHz两位微机械移相器

采用分布式微机械传输线结构实现了两位移相器,并且为了减小传输线负载电容和驱动电压首次提出了用共面波导传输线来驱动微机械桥的结构(共面波导驱动结构).结果显示驱动电压小于20V,20GHz时两位移相器的相移为0°/20.1°/41.9°/68.2°,插入损耗为-1.2dB.在DC到32GHz的范围内相移具有良好的线性,插入损耗小于-1.8dB,反射损耗好于-11dB.实验结果表明了该结构在高介电常数衬底上制造低插损、宽带数字微机械射频移相器的潜力     

一个DC-32GHz两位微机械移相器

采用分布式微机械传输线结构实现了两位移相器,并且为了减小传输线负载电容和驱动电压首次提出了用共面波导传输线来驱动微机械桥的结构(共面波导驱动结构).结果显示驱动电压小于20V,20GHz时两位移相器的相移为0°/20.1°/41.9°/68.2°,插入损耗为-1.2dB.在DC到32GHz的范围内相移具有良好的线性,插入损耗小于-1.8dB,反射损耗好于-11dB.实验结果表明了该结构在高介电常数衬底上制造低插损、宽带数字微机械射频移相器的潜力.     

基于微机电系统开关的四位移相器设计

为了解决相控阵雷达小型化和低损耗的问题,设计了一个工作频率为2.2 GHz的射频微机电系统(MEMS)四位开关线型移相器。首先分析了直接接触式MEMS串联开关的插入损耗和隔离度,并得到仿真结果。在此基础上设计了基于该开关的移相范围为0~180o的四位移相器电路,相移量为12o每步。采用HFSS软件对其进行仿真,得到移相精确度、插入损耗和隔离度等关键结果,移相器工作在2.2 GHz时,隔离度大于20 dB,插入损耗小于1 dB。该设计与传统移相器相比体积更小,且具有更小的插入损耗和更大的隔离度。     

4位毫米波MEMS移相器

报道了一款开关线型Ka波段MEMS移相器,采用了16只悬臂梁结构MEMS开关,实现了4位相移。采用阶梯阻抗共面波导(CPW)传输线设计,实现了一种新型而紧凑的移相器阻抗匹配的结构。采用RF MEMS低温表面牺牲层工艺,在高阻硅片上实现了单片4位MEMS移相器样品,在35GHz频点,平均插入损耗-5.8dB,16态相移误差≤8.5°,芯片尺寸5.3mm×2.9mm。分析MEMS移相器插损的构成,提出了降低MEMS移相器插损的工艺途径,预期Ka波段4位MEMS移相器的平均插损可降为-2.6dB,满足低成本毫米波MEMS相控阵系统应用需求。     

Ku波段GaAs单片集成移相器

本文报道了一种工作在16.0～17.0GHz单片集成180°的移相器.文中通过对无源工作的GaAs MESFET的建模,分析了影响移相器性能的主要参数,以及这些参数的最佳取值.制作在2.45×2.80×0.2mm芯片上的移相器其参数为:插损小于4.03dB,输入电压驻波比小于1.66,输出电压驻波比小于1.71,相移偏差在12.5°以内.     

低损耗360°X波段模拟移相器

介绍了低损耗反射型模拟移相器电路并报道了实验结果。这个电路集几个设计特征为一体,在X波段产生线性360°相移并且实现在所有相位状态下插损仅4.8dB,变化±0.5dB。这些结果提高了以前报道的X波段移相器性能,相移范围大,衰减小以及随相位状态变化幅度变化低。     

双膜桥微波MEMS开关

介绍了一种双膜桥微波MEMS开关，给出了开关的设计与优化方法，建立了开关的仿真模型，使用硅表面微机械工艺制造了双膜桥开关样品，其主要结构为硅衬底上制作CPW金属传输线电极和介质层，然后制作具有微电感结构的金属膜桥，提高了开关隔离度。利用HFSS软件仿真的结果表明，该开关在微波低频段(3～6GHz)有着很好的隔离性能。研制的开关样品在片测试的电性能指标为：插损小于0．3dB，隔离度大于40dB，驱动电压小于24V。     

双膜桥微波MEMS开关

介绍了一种双膜桥微波MEMS开关,给出了开关的设计与优化方法,建立了开关的仿真模型,使用硅表面微机械工艺制造了双膜桥开关样品,其主要结构为硅衬底上制作CPW金属传输线电极和介质层,然后制作具有微电感结构的金属膜桥,提高了开关隔离度.利用HFSS软件仿真的结果表明,该开关在微波低频段(3～6GHz)有着很好的隔离性能.研制的开关样品在片测试的电性能指标为:插损小于0.3dB,隔离度大于40dB,驱动电压小于24V.     

11.25°毫米波数字移相器的设计

设计了一种Ka波段11.25°数字移相器。采用一前一后加载支线的方式,在Ka波段内研制出11.25°数字移相器。该移相器在30～31GHz工作频带内,驻波比小于1.65,插入损耗小于3dB,固定相移11.25°,相位精度达到±3°。     

Ka波段开关线型MEMS移相器的设计与研究

面向现代通信及相控阵雷达领域的需求,设计了一种移相间隔为22.5°的Ka波段4位开关线型射频MEMS移相器。主要对实现移相功能的四个移相单元进行了设计,采用台阶补偿技术优化移相单元上下通路分工选通,以提供最佳的阻抗匹配;采用直角转角结构,设计了可提高CPW直角性能的延迟线,并对应用该延迟线的4位开关线型移相器进行了总体设计。用HFSS进行建模仿真,结果表明,在0~40 GHz工作频段内,16个状态的插入损耗均小于2.15 dB,回波损耗均大于19.18 dB,驻波比均小于1.25,在40 GHz频点处的相移误差在1.57°以内,整体尺寸为10 mm²。     

低电压驱动的硅基Ka波段级联式MEMS移相器

通过在共平面波导上周期性地分布微机械电容,外加电压驱动改变电容值,可实现级联式MEMS移相器.本文讨论了优化相移特性对共平面波导特性阻抗及下拉电压的要求,通过工艺参数优化制备了高阻硅基上的Ka波段级联式MEMS移相器,测试结果表明制备器件具有较低的驱动电压,8V时即产生明显的相移量,在36GHz处15V驱动电压时相移量为118°,25V时为286°.对微结构弹性膜的机械振动寿命测试表明,13级级联的MEMS移相器所有弹性膜同步振动的寿命为3×10⁶次.为器件的实用化提供了重要保障.     

基于SP4T开关的4位MEMS开关线式移相器设计

设计了一款4位MEMS开关线式移相器,由SP4TMEMS开关和微带传输线构成,工作于X波段。单刀四掷(single pole 4throw,SP4T)开关用于切换两条不同电长度的信号通道,即参考相位通道和延迟相位通道。每个SP4T开关包含4个悬臂梁接触式RF MEMS串联开关。介绍了4位MEMS开关线式移相器的总体设计,并给出了其关键部件SP4T开关和相位延迟线的设计细节。采用ADS软件仿真分析了器件的电气性能。仿真分析得到:SP4T开关在中心频率10GHz处的回波损耗为-36dB,插入损耗约为0.18dB;移相器各相位的回波损耗均低于-15dB,插入损耗为-0.8～-0.4dB。这种射频MEMS移相器具有小型化、低功耗和高隔离度的优点。     

A 2-bit RF MEMS phase shifter in a thick-film BGA ceramic package

The development of a thick-film hermetic BGA package for a radio-frequency (RF) microelectromechanical systems (MEMS) 2-bit phase shifter is presented. The measured packaged MEMS phase shifter average in-band insertion loss was 1.14 dB with an average return loss of 15.9 dB. The package transition insertion loss was less than 0.1 dB per transition with excellent agreement between simulated and measured results. It was also demonstrated that the RF MEMS phase shift performance could be improved to obtain a phase error of less than 3.3 degrees. The first reported measurements of the average rise and fall times associated with a MEMS circuit (in this case a 2-bit phase shifter) were 26 and 70 /spl mu/s, respectively. The advent of packaged RF MEMS phase shifters will reduce the cost (both design and building) of future phase arrays.     

A Ku‐Band 5‐Bit Phase Shifter Using Compensation Resistors for Reducing the Insertion Loss Variation

This paper describes the performance of a Ku‐band 5‐bit monolithic phase shifter with metal semiconductor field effect transistor (MESFET) switches and the implementation of a ceramic packaged phase shifter for phase array antennas. Using compensation resistors reduced the insertion loss variation of the phase shifter. Measurement of the 5‐bit phase shifter with a monolithic microwave integrated circuit demonstrated a phase error of less than 7.5° root‐mean‐square (RMS) and an insertion loss variation of less than 0.9 dB RMS for 13 to 15 GHz. For all 32 states of the developed 5‐bit phase shifter, the insertion losses were 8.2 ± 1.4 dB, the input return losses were higher than 7.7 dB, and the output return losses were higher than 6.8 dB for 13 to 15 GHz. The chip size of the 5‐bit monolithic phase shifter with a digital circuit for controlling all five bits was 2.35 mm × 1.65 mm. The packaged phase shifter demonstrated a phase error of less than 11.3° RMS, measured insertion losses of 12.2 ± 2.2 dB, and an insertion loss variation of 1.0 dB RMS for 13 to 15 GHz. For all 32 states, the input return losses were higher than 5.0 dB and the output return losses were higher than 6.2 dB for 13 to 15 GHz. The size of the packaged phase shifter was 7.20 mm × 6.20 mm.     

An X-band 22.5°/45° digital phase shifter based on switched filter networks

The design approach and performance of a 22.5°/45°digital phase shifter based on a switched filter network for X-band phased arrays are described. Both the MMIC phase shifters are fabricated employing a 0.25μm gate GaAs pHEMT process and share in the same chip size of 0.82×1.06 mm². The measurement results of the proposed phase shifters over the whole operating frequency range show that the phase shift error is less than 22.5°±2.5°, 45°±3.5°, which shows an excellent agreement with the simulated performance, the insertion loss is within the range of 0.9-1.2 dB for the 22.5°phase shifter and 0.9-1.4 dB for the 45°phase shifter, and the input/output return loss is better than -12.5 and -11 dB respectively. They also achieve the similar P_1dB continuous wave power handing capability of 24.8 dBm at 10 GHz. The phase shifters show a good phase shift error, insertion loss and return loss in the X-band (40%), which can be employed into the wide bandwidth multi-bit digital phase shifter.     

一种S频段反射型可调模拟移相器的设计

设计了一种应用于S频段卫星通信相控阵系统的反射型可调模拟移相器。该移相器利用三分支线定向耦合器扩展了带宽,改善了工作频段内驻波;采用传输线和变容二极管构成的L型反射负载扩大了相移量。测试结果表明,在上行频段1.98～2.01 GHz内,相移量达到191°±1°,在下行频段2.17～2.2 GHz内,相移量达到186°±0.1°;插入损耗优于3.3 dB且插入损耗波动小于1 dB,回波损耗在整个电压调谐范围内均大于20 dB。该移相器结构简单、便于调节且价格低廉,在卫星通信领域有一定的应用价值。