硅基铝T形梁MEMS可变电容的设计与模拟

提出了一种新颖的运用于射频通信系统VCO中的RFMEMS可变电容。该电容使用平行板和T形梁结构,使用硅衬底,整个结构由铝材料组成,结构简单,与集成电路工艺兼容,从而能够实现片上可变电容。通过静电力驱动上极板向下运动,电容值相应地发生改变,当上极板加电压从2.4V变化到4.3V时,电容值从0.25pF变化到0.33pF,变化率为中心电容的27%。使用Coventor软件对该器件进行了模拟,给出的模拟结果包括容量、调节范围、瞬时响应、Pullin电压和运用该可变电容的VCO的电路模拟。

Design and Simulation of a Parallel Plate Variable Capacitor Based on Silicon with Novel T Shape Al Beams

A novel structure for the RF MEMS variable capacitor for RF communication was presented. The capacitor is composed of four novel T shape beams linked with a large area plate. The capacitor is based on silicon and the whole structure is made of Al, very simple, compatible with the CMOS IC process, so the variable capacitor is suitable for the monolithic integration. The spacing between the two parallel plates is changed by electrostatic actuation applied voltage from 2.4 V to 4.3 V so that the capacitor can be tuned from 0.25 pF to 0.33 pF, the range is 27%. The simulation results are presented, including capacitance, tuning range, transient response, Pull-in voltage and VCO simulation results used the RF MEMS capacitor. The results are used by the Coventorware.