InP基HEMTs器件16参数小信号模型

摘要

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.%In this paper,an improved 16-element small-signal topology for InAlAs/InGaAs InP-based HEMTs has been proposed.The gate-source resistance(Rgs)is introduced into the topological structure to characterize the gate leakage current caused by the short gate channel spacing.The output conductance(gds)and drain delay factor (τds)are proposed to characterize the impact of drain voltage on channel current and also the phase change by drain-source capacitor(Cds),which can improve the fitting accuracy of S22.The parasitic elements are calculated through open and short dummy structures,and the intrinsic parameters are extracted by Y-parameters after de-em-bedding the external parasitic parameters.The ultimate values of parameters are determined by optimization proce-dure to gain the best fitting precision.The results show that the simulation values of S-parameters and frequency characteristics fit well with the measured values,and the introduction of Rgsand τdsreduces the model error.The accurate and appropriate small signal model for InP-based HEMTs would be of great importance in the design of high-frequency circuits.