FET大信号模型中等效电容方程的改进

Improvement of the Equivalent Capacitance Equation in FET′S Large Signal Model

精确地描述FET器件大信号微波特性阻抗对单片微波集成电路设计极其重要。为了能准确地模拟FET器件大信号微波特性,在大信号器件模型中,有必要研究栅等效电容模型,尤其在高频段。在总结前人研究的基础上,构造了新型的栅源/栅漏电容方程。通过与6×80μm GaAs PHEMT器件大信号负载牵引测试数据的对比,表明:精确的栅等效电容模型极大地提高非线性模型对FET大信号特性的预测能力。这将有助于器件模型和MMIC设计。

It is very important to describe FET′s large-signal impedance accurately for MMIC design.In order to simulate FET′s large signal characteristic,it is necessary to research its gate equivalent capacitance model in the large signal model,especially in high frequency.Based on previous results,the paper deduces a new gate-source/gate-drain capacitance equation.By comparing the loadpull results of a 6×80 μm GaAs PHEMT device,it is shown that the accurate gate equivalent capacitance model improves the precision of FET′s large signal model greatly.This helps the research of device model and MMIC design.