GaAs衬底共面波导S参数标准样片研制

GaAs等固态微波裸芯片电性能测试需要采用探针将共面波导参考面过渡到同轴参考面。设计制作了用于微波探针校准的GaAs衬底的计量级标准样片,包括SOLT 和TRL 校准模块,以及匹配传输线、衰减及驻波等验证模块。提出了平衡电桥结构,兼具衰减驻波标准,带内平坦,且工艺适应性好。经过与国外校准片比对,验证了频率覆盖100 MHz ~50 GHz,驻波比测量范围:1.1,1.5,2.5,5,10;衰减测量范围:-1 dB,-2 dB,-3 dB,-10 dB,-20 dB,-30 dB,-40 dB;匹配负载反射损耗小于-30 dB。同时提取了SOLT校准模块的矢网校准用参数。     

40GHz 陶瓷衬底SOLT 校准片研制与定标技术研究

在片测试系统在微波单片集成电路MMIC 的设计建模及生产检验中有着必不可少的作用。由于测试 参考面从矢网的同轴接口转移到微波探针,因此需要用共面波导校准片校准。设计制作了用于在片测试系统校准 的陶瓷衬底的SOLT 校准片,并对校准片进行了建模,提取出了1 ~40GHz 频段内片上负载及短路件的等效电阻及寄 生电感参量、直通件的延时参量。片上负载的电阻分量约为45赘,回波损耗在1 ~ 30GHz 小于-20dB;在30 ~ 40GHz 小于-10dB。验证了SOLT 校准片设计、制作及定标的整个工艺过程的有效性。     

（英）钡铁氧体薄膜自偏置毫米波环行器设计与制备

基于厚度为10 μm的钡铁氧体薄膜设计,制备了共面波导结构的毫米波薄膜环行器.这种薄膜环行器不需要外加磁体,在34 GHz和37.6 GHz显示出环行特性,其非互易效应大于15 dB.结果表明,采用共面波导结构可以实现薄膜环行器.这种薄膜环行器具有和单片微波集成电路集成的潜在应用.     

提取共面微波探针S 参数的方法*

共面微波探针是裸芯片测量信号输入/输出的重要媒介,通过与晶圆片物理接触,建立起测量系统与芯片之间 的信号连接通道。为了获得共面微波探针完整准确的S 参数,设计并实现了“两步法”测量方案,首先在同轴端口进行校准,然 后在探针尖端口进行第二步校准。通过与出厂数据进行对比分析,证明了方案的可行性,同时指出在片校准件预校准的重要 性。另外,讨论了氧化铝和砷化镓两种材料在片SOLT 校准件对于探针S 参数提取中的影响,实验显示二者相角偏差达到 39.8°,回波损耗呈现规则性的变化,全部测量数据的频段覆盖1~40 GHz,最终给出了优化的测量方案。     

MMIC在片测试探头的研究与设计

微波单片集成电路（MMIC）在片测试技术是应用于MMIC和高速集成电路研究、生产的新型测试技术。MMIC在片测试探头是MMIC在片测试系统的关键部件。本文研究并设计了介质基片共面波导（CPW）探头,测试并分析了探头性能。该探头在2－18GHz范围内插入损耗小于1．5dB,回波损耗大于16dB。     

基于HTCC工艺的X波段小型化双面多腔体外壳的研制

基于高温共烧陶瓷(HTCC)工艺,利用共面波导和同轴线理论,设计了一款应用于X波段的双面多腔陶瓷外壳,以实现四通道T/R组件封装外壳的小型化、轻量化、低成本以及微波性能要求。首先,用HFSS软件对射频传输结构进行优化,其次利用HTCC工艺平台制作外壳样品,最后利用夹具、矢量网络分析仪和GSG探针测试微波传输性能。该外壳的微波性能测试结果为:X波段内,输出通道插入损耗≤0.7dB,回波损耗≥21.7dB;输入通道插入损耗≤1.18dB,回波损耗≥14.6dB。在考虑了测试基板和所键合金丝影响之后,测试结果与设计值吻合度较好。     

MEMS微波功率传感器的共面波导优化设计

归纳了目前存在的一些减小共面波导损耗的方法,用HFSS模拟了这些方法的插入损耗和回波损耗.根据微波功率传感器的特点选取了二氧化硅隔离层的结构来制作共面波导,指出了这种结构存在的缺陷,并运用半导体物理的知识解释了造成缺陷的原因,最后提出了改进结构并通过HFSS模拟证实了这些结构的正确性.从最终的结果来看,三种优化结构得到的插入损耗绝对值均减小到了0.6dB以下,回波损耗也降到了-30dB以下.     

基于XeF_2硅刻蚀工艺的低阻硅衬底低损耗共面波导

在低阻硅(1~10Ω.cm)衬底上采用XeF2硅腐蚀工艺成功制备了长度为2 mm、结构尺寸为w/s=40/60μm间断悬浮和全悬浮两种结构的共面波导。SEM照片显示器件释放后的悬浮结构未出现粘附或破裂现象。通过WYKO三维形貌观察得到两种结构共面波导悬浮信号线最大翘曲量分别为10μm和16μm。微波性能测试结果表明两种悬浮结构共面波导在1~10 GHz频率范围内插入损耗分别低于4.5 dB/2 mm和3.2 dB/2 mm,远小于制作在低阻硅衬底上的普通共面波导插入损耗9.4 dB/2 mm;在1~3 GHz频率范围内插入损耗分别低于0.54 dB/2 mm和0.17 dB/2 mm,小于制作在高阻硅(1 400~1 500Ω.cm)衬底上普通共面波导的插入损耗0.55 dB/2 mm。     

在高阻硅衬底上制备低微波损耗的共面波导

分别在普通的低阻硅衬底、带有3μm厚氧化硅介质层的低阻硅衬底和高阻硅衬底上设计并制备了微波传输共面波导.结果表明,低阻硅衬底导致过高的微波损耗从而不能使用,通过加氧化硅介质层,微波损耗可以大大减少,但是需要较厚的氧化硅厚度.直接制备在高阻硅衬底上的共面波导在所测试的26GHz的频率范围内获得低于2dB/cm的微波损耗,而且工艺十分简单.     

Low-Microwave Loss Coplanar Waveguides Fabricated on High-Resistivity Silicon Substrate

分别在普通的低阻硅衬底、带有3μm厚氧化硅介质层的低阻硅衬底和高阻硅衬底上设计并制备了微波传输共面波导.结果表明,低阻硅衬底导致过高的微波损耗从而不能使用,通过加氧化硅介质层,微波损耗可以大大减少,但是需要较厚的氧化硅厚度.直接制备在高阻硅衬底上的共面波导在所测试的26GHz的频率范围内获得低于2dB/cm的微波损耗,而且工艺十分简单.     

A 2–40 GHz Probe Station Based Setup for On-Wafer Antenna Measurements

A probe station based setup for on-wafer antenna measurements is presented. The setup allows for measurement of return loss and radiation patterns of an on-wafer antenna-hence-forth referred to as the antenna under test (AUT), radiating at broadside and fed through a coplanar waveguide (CPW). It eliminates the need for wafer dicing and custom-built test fixtures with coaxial connectors or waveguide flanges by contacting the AUT with a coplanar microwave probe. In addition, the AUT is probed exactly where it will be connected to a transceiver IC later on, obviating de-embedding of the measured data. Sources of measurement errors are related to calibration, insufficient dynamic range, misalignment, forward scattering from nearby objects, and vibrations. The performance of the setup is demonstrated from 2 to 40 GHz through measurement of an on-wafer electrically small slot antenna (lambda₀/35 times lambda₀/35,3.5 times 3.5 mm²) radiating at 2.45 GHz and an aperture coupled microstrip antenna (2.4 times 1.7 mm²) radiating at 38 GHz.     

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 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.     

低阻硅衬底上形成的低损耗共平面波导传输线

在厚膜多孔硅 (PS) /氧化多孔硅 (OPS)衬底上 ,结合聚酰亚胺涂层改善表面 ,研制低损耗、高性能射频 (RF) /微波 (MW)共平面波导CPW(CoplanarWaveguide) .通过在N和P型硅上形成不同厚度PS膜 ,并对其上的CPW进行分析比较 ,厚膜PS与石英的共面波导插入损耗非常接近 ,远小于在 2 0 0 0Ω·cm高阻硅上形成的多晶硅 -氧化硅组合衬底 :在 0 33GHz范围 ,插入损耗小于 5dB/ 1.2cm ;33 4 0GHz范围 ,小于 7.5dB/ 1.2cm .     

Scattering parameter and bit error rate characterization of hightemperature superconducting coplanar transmission lines

We report the gigahertz experimental results of time and frequency performance on YBCO high temperature superconductor (HTS) and gold coplanar transmission lines. An on-wafer direct probing measurement system was used to collect data at cryogenic temperatures on both YBCO and gold coplanar lines. The insertion loss of the 6-cm lines at a frequency of 3.0 GHz was measured to be -0.12 dB for the superconducting line compared to -10.7 dB for the gold line at 80 K. Error rate and eye-diagram measurements were performed on the packaged lines and show the correlation between the insertion loss of the line and the attenuation of a Pseudo Random Bit Sequence (PBRS). The superconducting line measured at 77 K had a BER rate of less than 10^-11 at a data rate of 3 Gb/s. The measured eye height was 350 mV for the YBCO compared to 100 mV for a gold line at 3 Gb/s and a temperature of 77 K for the packaged 6-cm lines     

Very broadband distributed amplifier to 75 GHz

Distributed amplifiers were fabricated successfully with a gain of 8 dB+or-1 dB in the frequency range 5-75 GHz measured on-wafer. The associated input and output matching is better than -10 dB. To the authors' knowledge this is a new performance record, not only for GaAs based circuits but also for InP based MMICs. The MMICs were realised in coplanar waveguide technology.<>     

低压低能耗应用的InGaAs／AlGaAsPHEMT单片微波SPDT开关

提出了微波频率下ＰＨＥＭＴ在作开关运用时一种简化的等效电路模型，其模型参数可从对实际ＰＨＥＭＴ芯片的在片微波测试方便地确定。对于电路中元件采用不同尺寸组合情形下所进行的开关性能（插入损耗，隔离度，输入及输出反射损耗）的模拟计算表明，与实验结果符合良好。在对串／并联ＰＨＥＭＴ型ＳＰＤＴ开关的ＣＡＤ优化设计基础上进行了ＩｎＧａＡｓ／ＡｌＧａＡｓＰＨＥＭＴ单片ＳＰＤＴ微波开关的实验研制。从研制的ＭＭＩＣ芯片上在片测试得到的结果为：对应新的个人通信频段的应用，在０～２ＧＨＺ范围内，插入损耗＜１．０ｄＢ，隔离度＞５０ｄＢ，输入及输出反射损耗均优于２４ｄＢ。研制的这种高性能单片开关还可在低至－２．０Ｖ的控制电压下工作。     

一种新颖的DC～50GHz低插入相移MMIC可变衰减器

介绍了一种新颖的 DC～ 5 0 GHz低相移、多功能的 Ga As MMIC可变衰减器的设计与制作 ,获得了优异的电性能。微波探针在片测试结果为 :在 DC～ 5 0 GHz频带内 ,最小衰减≤ 3 .8d B,最大衰减≥ 3 5± 5 d B,最小衰减时输入 /输出驻波≤ 1 .5 ,最大衰减时输入 /输出驻波≤ 2 .2 ,衰减相移比≤ 1 .2°/d B。芯片尺寸 2 .3 3 mm× 0 .68mm× 0 .1 mm。芯片成品率高达 80 %以上 ,工作环境温度达 1 2 5°C,可靠性高 ,稳定性好     

GaAs功率单片脉冲在片测试技术研究

讨论了功率单片在片脉冲测试中在片校准技术、脉冲功率测试技术等难题,并在讨论以上问题的基础上,实现工程化应用,该测试技术能够有效覆盖至40GHz。在建立的脉冲大功率在片测试系统上对输出功率典型值5W的GaAs功率单片放大器进行测试验证,测试结果和装架测试结果相比较,输出功率误差<0.2dB。