【摘要】 用解析的方法模拟了T＝300K和77K时，fT和fmax与集电极电流密度Jc的关系，在大电流下考虑了异质结势垒效应的影响。模拟结果和用数值方法以及实验所得到的结果一致。同时，还建立了与之相应的Si／SiGeeb异质结和SiGe／Sibc异质结电容模型。更多还原

【Abstract】 The two importance parameters of frequency characteristics are cutoff frequence (f T ) and maximum frequency of oscillation (fmax ). In this paper,while effects of heterojunction barrier under high current density are taken into account, the dependence of fT and fmax on the collector current density at 300 K and77 K is modelled and simulated analytaically. The simulation results are in agreement with published numerical and experimental results. Meanwhile the heterojunction capacitance models for eb junction under forward voltage and for be junction under various collector currents are developed.更多还原