一种基于RF MEMS开关的四端口电子校准件设计

针对射频多端口器件微波测试需求,基于SOLT校准原理设计了一种工作频率在DC~12 GHz范围内、基于RF MEMS开关的四端口电子校准件。数值仿真结果表明,在短路状态下,器件的回波损耗小于0.15 dB;在直通状态下,器件的插入损耗小于0.5 dB,端口之间的隔离度大于20 dB;在开路状态下,器件的回波损耗小于0.3 dB,端口之间的隔离度大于25 dB;同时采用微表面加工工艺,利用磁控溅射工艺对负载电阻进行了制备,其测试结果约为50 Ω,符合设计要求。设计的基于RF MEMS开关的四端口校准件,具有射频性能好、体积小、易于集成等优点,能够满足X波段微波多端口器件在片测试的应用需求。     

Ka波段波导-微带转接器的设计

本文分析了Ka波段波导-微带探针转接微波特性,利用全波分析软件对它进行了仿真分析,设计了Ka波段波导-微带转接器,实验测试与仿真设计结果十分相近:在26.5～40GHz内插入损耗0.75～1.27dB,回波损耗-38～-23dB,该波导-微带转接器在整个频段内性能良好,符合工程应用的要求.     

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。     

一种Ka频段MEMS开关的研制

设计了一种应用于Ka频段的并联电容式MEMS开关,该开关利用表面牺牲层工艺制备,具有低损耗、高隔离度等特点。经测试,开关在Ka频段内,回波损耗优于30dB,插入损耗典型值-0.13dB@27GHz,优于-0.28dB@40GHz,隔离度全频段优于22dB,驱动电压在50V~70V范围。     

应用于Ka波段无线通信的发射前端模块设计与制造

介绍一种应用于Ka波段无线通信的发射前端模块,该模块由混频器、微带滤波器、压控振荡器、倍频器、功率放大器构成。射频(RF)信号工作在27.4~28 GHz频段内,中频信号固定在1 GHz。仿真结果显示,在工作频段内发射前端增益超过10 dB,发射功率为11.823 dBm,并且交调信号被抑制在63 dBc以下。在全部芯片工作的条件下,温度仿真结果显示芯片的结温低于64℃。测试结果显示,在工作频段内输出端信号线插入损耗低于0.34 dB,回波损耗小于-20 dB,VCO的8分频输出功率是-10.66 dBm。     

一种Ka 波段固态功率合成器

：文章介绍了一种新型的Ka 波段固态空间功率合成器。在此功率合成器H 面中插入一个电阻片,可以极大地提 高功率合成器的隔离度和回波损耗,通过三维仿真软件HFSS 仿真计算证明了可行性,最后实现一个完全对称的两路功 率分配/合成器。仿真结果显示,此功率合成器在29-31GHz 内,插入损耗小于0.21dB,隔离度优于19dB,端口回波损耗 优于27dB。     

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。     

用于Ka波段卫星通信系统的LTCC滤波器

通过对自主设计流片的Ka波段LTCC滤波器的分析,总结出了一套行之有效的Ka波段LTCC模块的设计方法。试验结果表明,这种将电磁场仿真和实际测试相结合的方法,有效地减小由于模型和工艺误差带来的电路性能的降低,其最终测试结果为在26～30GHz的4GHz带宽范围内带内损耗为1.3dB,输入输出驻波均小于1.5dB。     

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。     

应用于可重构天线的RF MEMS开关设计

针对应用于可重构天线的RF MEMS开关进行研究,并通过HFSS软件对其进行仿真分析,开关处于关闭状态(down)时,并工作在5GHz时,开关插入损耗S21仅为-0.01dB,回波损耗在-30dB附近。开关处于闭合状态(up),在1GHz^10GHz频段,隔离度S21均小于-40dB。     

Fabrication and accelerated hermeticity testing of an on-wafer package for RF MEMS

A hermetic silicon micromachined on-wafer dc-to-40-GHz packaging scheme for RF microelectromechanical systems (MEMS) switches is presented. The designed on-wafer package has a deembedded insertion loss of 0.03 dB per transition up to 40 GHz (a total measured loss of 0.3 dB including a 2.7-mm-long through line) and a return loss below -18dB up to 40 GHz. The hermeticity of the packaged is tested using an autoclave chamber with accelerated conditions of 130/spl deg/C, 2.7 atm of pressure, and 100% relative humidity. The fabrication process is designed so as to be completely compatible with the MEMS switch process, hence, allowing the parallel fabrication of all the components on a single wafer. The on-wafer proposed packaging approach requires no external wiring to achieve signal propagation and, thus, it has the potential for lower loss and better performance at higher frequencies.     

A DC-to-40 GHz four-bit RF MEMS true-time delay network

A monolithic true-time delay (TTD) network containing sixteen metal-to-metal contact RF microelectromechanical systems (MEMS) switches has been successfully fabricated and characterized. The TTD network was designed to produce flat delay time over a dc-to-40 GHz bandwidth with full 360-degree phase control at 22.5-degree intervals at 10.8 GHz. Measurements show a close match to the designed delay times for all sixteen switch states with 2.2 to 2.6 dB of insertion loss at 10 GHz. The worst group delay ripple in the dc-to-30 GHz range was 3 ps, well within the single bit delay time of 5.8 ps     

五位RF MEMS开关延迟线移相器

设计并研制了一种6～11GHz、超宽带5位RF MEMS开关延迟线移相器,器件实现了5位延迟:λ、2λ、4λ、8λ、16λ。该器件采用微带混合介质多层板技术,分4层制作,尺寸为45mm×20 mm。整个器件包括20个RFMEMS悬臂梁开关,用60～75V的静电压驱动。6～11GHz频带内,对32个相移态的测试结果表明:一般回波损耗S11<-10dB,各状态平均插入损耗为-8～-10dB;中心频率处,器件可实现的最大延迟位时延为1680ps,总时延为3255ps。     

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。     

A 60-GHz uniplanar MMIC 4/spl times/ subharmonic mixer

A uniplanar GaAs monolithic microwave integrated circuit /spl times/4 subharmonic mixer (SHM) has been fabricated for 60-GHz-band applications using an antiparallel diode pair in finite ground coplanar (FGC) waveguide technology. This mixer is designed to operate at an RF of 58.5-60.5 GHz, an IF of 1.5-2.5 GHz, and an LO frequency of 14-14.5 GHz. FGC transmission-line structures used in the mixer implementation were fully characterized using full-wave electromagnetic simulations and on-wafer measurements. Of several mixer configurations tested, the best results show a maximum conversion loss of 13.2 dB over the specified frequency range with a minimum local-oscillator power of 3 dBm. The minimum upper sideband conversion loss is 11.3 dB at an RF of 58.5 GHz and an IF of 2.5 GHz. This represents excellent performance for a 4/spl times/ SHM operating at 60 GHz.     

Piezoelectrically actuated RF MEMS DC contact switches with low voltage operation

In this paper, fully integrated radio frequency (RF) microelectromechanical system (MEMS) switches with piezoelectric actuation have been proposed, designed, fabricated, and characterized. At a very low operation voltage of 2.5V, reliable and reproducible operation of the fabricated switch was obtained. The proposed RF MEMS switch is comprised of a piezoelectric cantilever actuator with a floated contact electrode and isolated CPW transmission line suspended above the silicon substrate. The measured insertion loss and isolation of the fabricated piezoelectric switch are -0.22 dB and -42dB at a frequency of 2GHz, respectively.     

毫米波数控移相器的设计与制作

移相器是毫米波相控阵雷达收发系统重要电路,基于安捷伦IC-CAP软件及砷化镓原片工艺线,研究了砷化镓毫米波开关器件测试、建模技术及其应用。采用0.15μm GaAs PHEMT工艺成功制作了一款Ka波段5位数控移相器MMIC,对毫米波数控移相器MMIC集成电路的设计、制作过程进行了阐述,并给出了测试结果。电路设计采用了开关滤波拓扑结构,运用微波探针在片测试系统对芯片进行了实测,在34~36 GHz范围内获得了优异的电性能。给出了移相器的测试曲线,32态均方根移相误差(RMS)5°,插入损耗典型值8 dB,输入/输出电压驻波比系数典型值2,芯片尺寸为2.5 mm×1.5 mm×0.1 mm。     

A fully integrated SOI RF MEMS technology for system-on-a-chip applications

In this paper, a silicon-on-insulator (SOI) radio-frequency (RF) microelectromechanical systems (MEMS) technology compatible with CMOS and high-voltage devices for system-on-a-chip applications is experimentally demonstrated for the first time. This technology allows the integration of RF MEMS switches with driver and processing circuits for single-chip communication applications. The SOI high-voltage device (0.7-/spl mu/m channel length, 2-/spl mu/m drift length, and over 35-V breakdown voltage), CMOS devices (0.7-/spl mu/m channel length and 1.3/-1.2 V threshold voltage), and RF MEMS capacitive switch (insertion loss 0.14 dB at 5 GHz and isolation 9.5 dB at 5 GHz) are designed and fabricated to show the feasibility of building fully integrated RF systems. The performance of the fabricated RF MEMS capacitive switches on low-resistivity and high-resistivity SOI substrates will also be compared.     

A DC to 10-GHz 6-b RF MEMS time delay circuit

A 6-b radio frequency (RF) microelectromechanical system (MEMS) time-delay circuit operating from dc to 10 GHz with 393.75-ps total time delay is presented. The circuit is fabricated on 250-/spl mu/m-thick alumina and uses metal contacting RF MEMS switches to realize series-shunt SP4T switching networks. The circuit demonstrates 1.8+/-0.6 dB of loss at 10 GHz and has linear phase response across the entire band with accuracy of better than a least significant bit for most states.