InAlAs/InGaAs PHEMTs的设计及其110GHz全频段小信号建模

90-nm T-shaped gate InP-based In_0.52Al_0.48As/In_0.6Ga_0.4As pseudomorphic high electron mobility transistors were designed and fabricated with a gate-width of 2×30 μm,a source-drain space of 2.5 μm,and a source-gate space of 0.75 μm.DC,RF and small-signal model characterizations were demonstrated.The maximum saturation current density was measured to be 755 mA/mm biased at V_gs=0.6 V and V_ds=1.5 V.The maximum extrinsic transconductance was measured to be 1006 mS/mm biased at V_ds=—0.1V and V_ds=1.5 V.The extrapolated current gain cutoff frequency and maximum oscillation frequency based on S-parameters measured from 0.5 to 110 GHz were 180 and 264 GHz,respectively.The inflection point（the stability factor k=1）where the slope from-10 dB/decade（MSG） to-20 dB/decade（MAG） was measured to be 83 GHz.The smallsignal model of this device was also established,and the S-parameters of the model are consistent with those measured from 0.5-110 GHz.     

用于太赫兹探测的InP基异维肖特基二极管

异维肖特基二极管(HDSD)是一种具有三维金属-二维半导体结的特殊的肖特基势垒二极管。由于具有较小的结电容和串联电阻,HDSD在太赫兹探测中很有应用潜力。本文研制了InP基HDSD,据我们所知相关工作尚未被报道过。与GaAs基HDSD相比,可以预期InP基HDSD有着更好的性能,一方面因为更高的电子迁移率和二维电子气(2DEG)浓度,另一方面因为更小的肖特基势垒高度。通过交流测量得到的截止频率高于500GHz,表明InP基HDSD具有应用于太赫兹探测的潜力。     

一种改进的基于110 GHz在片S参数测试的HEMT器件寄生电阻提取方法

提出了一种改进的高电子迁移率晶体管寄生电阻提取方法,该方法利用了特殊偏置点(Vgs＞Vth,Vds=0V)的等效电路模型,推导了寄生电阻的表达式,采用半分析法对寄生电阻进行了优化.1～110 GHz S参数实测结果和仿真的S参数一致,证明该方法是有效的.     

太赫兹InP基InAlAs/InGaAs PHEMTs的研制

研制了一种T型栅长为90 nm的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管(PHEMTs).该器件的总栅宽为2×25 μm,展现了极好的DC直流和RF射频特性,其最大饱和电流密度和最大有效跨导分别为894 mA/mm和1640 mS/mm.采用LRM+ (Line-Reflect-Reflect -Match)校准方法实现系统在1~110 GHz全频段内一次性校准,减小了传统的分段测试多次校准带来的误差, 且测试数据的连续性较好.在国内完成了器件的1~110 GHz全频段在片测试,基于1~110 GHz在片测试的S参数外推获得的截止频率ft和最大振荡频率fmax分别为252 GHz和394 GHz.与传统的测试到40 GHz外推相比,本文外推获得的fmax更加准确.这些结果的获得是由于栅长的缩短,寄生效应的减小以及1~110 GHz全频段在片测试的实现.器件的欧姆接触电阻率减小为0.035 Ω·mm.     

InAlAs/InGaAs/InP基PHEMTs小信号建模及低噪声应用

利用改进的小信号模型对采用100nmInAlAs/InGaAs/InP工艺设计实现的PHEMTs器件进行建模, 并设计实现了一款W波段单片低噪声放大器进行信号模型的验证。为了进一步改善信号模型低频S参数拟合差的精度, 该小信号模型考虑了栅源和栅漏二极管微分电阻, 在等效电路拓扑中分别用Rfs和Rfd表示.为了验证模型的可行性, 基于该信号模型研制了W波段低噪声放大器单片.在片测试结果表明:最大小信号增益为14.4dB@92.5GHz, 3dB带宽为25GHz@85-110GHz.而且, 该放大器也表现出了良好的噪声特性, 在88GHz处噪声系数为4.1dB, 相关增益为13.8dB.与同频段其他芯片相比, 该放大器单片具有宽3dB带宽和高的单级增益.     

栅长为83-nm的毫米波低噪声InP基PHEMTs的研制

本文设计并实现了一种83-nm T型栅的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管（PHEMT）。该器件的总栅宽为2×30μm,展现了良好的DC直流、RF射频以及低噪声特性,包括最大饱和电流密度Idss和最大有效跨导gm,max分别为894mA/mm和1640mS/mm。基于1~110 GHz全频段在片测试的S参数外推获得的最大截止频率ft和最大振荡频率fmax分别为247GHz和392GHz。测得的器件拐点（稳定因子k=1）频率为102GHz,因此,基于拐点外推获得的fmax更加准确。采用冷源法完成器件的在片噪声参数的测试,测得的最小噪声系数NFmin在30GHz时为1dB,相关增益Gass为14.5dB。这些良好结果的获得是由于沟道层中InAs摩尔组分的增加,沟道层厚度的减小,栅长的缩短以及寄生效应的减小。这些优良的特性使得该器件非常适合于毫米波频段低噪声单片集成电路的应用。     

太赫兹在片S参数测量串扰修正方法研究

为修正太赫兹在片S参数测试时探针间串扰误差,提出了一种包含串扰的新型误差模型,以及基于此误差模型的校准方法.该方法分别对待校准和测试时的串扰误差.基于这一概念,开发了一种新型12项误差模型,将串扰误差视为与被测件(DUT)并联的独立二端口网络.在测量DUT前通过测量一对长度与DUT相同的开路标准实现对串扰误差的表征并移...     

InP基HEMTs器件16参数小信号模型

针对InAlAs/InGaAs InP基 HEMTs提出了一种16参数小信号拓扑结构.拓扑结构中引入栅源电阻(Rgs)表征短栅沟间距引起的栅泄漏电流效应.另外还引入输出跨导(gds)和漏延迟(τds)描述漏端电压对沟道电流的影响以及漏源电容(Cds)引起的相位变化,从而提高了S22参数拟合精度.外围寄生参数通过open和short拓扑结构计算得出,本征部分利用去除外围寄生参数后的Y参数计算得出,最终模型参数值经过优化以达到最佳拟合状态而确定.结果表明,s参数和频率特性的仿真值与测试数据拟合程度很好,Rgs和τds的引入降低了模型误差.准确合适的InP基HEMTs小信号模型对于高频电路设计非常重要.     

一种测量差分片上螺旋电感类器件的简便方法

This paper proposes a simple method of measuring differentially-excited on-wafer RF CMOS spiral inductor-like components.This method requires only two common ‘G-S-G＇ probes and an ordinary two-port VNA.Using a network instead of a detailed equivalent circuit, this method completes the de-embedding with only one ‘Through＇ dummy, and thus the measurements are greatly simplified.By designing the ports ‘Open＇ or ‘Shortcircuited＇ deliberately, a multi-port transformer can be transformed into three two-port networks with different terminators.Then, couplings between the two coils can be solved, and the differentially-excited scattering parameters（S-parameters） can be constructed.Also, a group of differential inductors and transformers were designed and measured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.     

一种基于10项误差模型的二端口矢量网络分析仪校准方法

在三通道二端口矢量网络分析仪(Vector Network Analyzer,VNA)的校准过程中,引入长度未知的50欧姆传输线段作为校准件代替常见的短路-开路-匹配-直通(Short-Open- Load-Thru,SOLT)校准算法中的匹配校准件,减少了校准件数量且不需要已知校准件的全部特性,不仅降低了测试成本,同...     

一种用于在片器件直接测量的新型SOLT校准方法

介绍了一种“针尖前移”的在片SOLT校准方法,使用这种校准方法可以将测试参考面直接校准到内部被测件,从而可以进行无去内嵌(De-embedding)操作的直接测量。通过对在片平面螺旋电感的测试验证,证明这是一种精确高效的新校准方法。     

基于能量守恒平均模型的开关变换器建模

文中介绍了一种常用的开关变换器建模方法——能量守恒平均法,依据能量守恒平均原理,建立连续模式下Buck变换器的直流和小信号模型,并给出开环传递函数。仿真分析表明,该模型能够准确描述变换器的频域特性,验证了理论推导的有效性。     

Power performance and scalability study of AlGaAs/GaAs double-recessed pseudomorphic high electron mobility transistors on unthinned substrate for coplanar waveguide circuit applications

We have investigated the power performance and scalability of AlGaAs/GaAs Double-Recessed Pseudomorphic High Electron Mobility Transistors (DR-PHEMTs) at 10 GHz on an unthinned GaAs substrate for CoPlanar Waveguide (CPW) circuit applications. It was found that the output power varied linearly with the logarithm of the device’s gate width ranging from 200 to 1000 μm. It increased at a rate of 0.01 dB/μm. That worked out to a doubling of output power (or 3 dB) for every 300 μm increase in the gate width. Gain decreased at a rate of about 0.005 dB/μm while PAE generally improved when the gate width was increased. As for DC measurement, the maximum transconductance of the device was about 375 mS/mm at V_G = −0.5 V and V_DS = 3 V. The gate-drain breakdown voltage (BV_GD) measured was −20 V, defined at I_G = −1 mA/mm. The microwave performance of the devices was measured on-wafer using a load-pull system at a bias of V_G = −0.5 V and V_DS = 8 V. For a device with a gate width of 1 mm, its saturated CW output power, gain and PAE value at 10 GHz was 27.5 dBm (0.55 W), 8 dB and 48%, respectively. At this same set of bias conditions, the value of f_t and f_max was 40 and 80 GHz, respectively.