Study On The Key Technology Of Radio Frequency MEMS Switch And Amplifier

Compared with p-i-n switch used in communication system, RF MEMS (Radio frequency micro-electron mechanical system) switch has low insertion loss, high isolation and linearity, and will be the key devices in future communication system. Its development and monolithic integration with RF front-end amplifier circuits will reduce volume of communication system for increasing reliability and stability, so it's important to promote of communication system miniaturization.This paper is focused on the key technologies of RF MEMS switch and monolithic amplifier integration, some researches have been under-taken as follows:1.Using dynamics theory, the poly-silicon and metal film bridge RF MEMS switch have been simulated and analysed, and the RF MEMS switch threshold voltage has been calculated. Focused on the insulated layer roughness of bridge RF MEMS switch, the analysed result is that the roughness must be controlled to 50-100 ? for ensuring off state capacitance change very low and decreasing sticky effect.2. For solving conflict between frequency band and gain of amplifier, some research on design technology of amplifier circuit have been done, and a novel amplifier circuit has been obtained. And high gain and wide frequency band of RF amplifier have been achieved, the simulated results indicate that the gain and frequency band of this circuit are 27 and 1 GHz respectively, and meet the requirements for RF amplifier.3. The research for the sacrificial layer etching and stress releasing technologies is done, the optimal technique is obtained, and the samples of poly-silicon and metal film RF MEMS switch are obtained. 4. Aiming at the problem of RF MEMS switch needing high resistivity substrate, whereas IC needing low resistivity substrate, the silicon substrates are divided into insulated poly-silicon and low resistivity silicon substrate by using the deep-groove etch, poly-silicon to refill and polishing etc. so the compatibility between RF MEMS switch and IC substrate is achieved. Combining the metal film RF MEMS CPW switch with planar IC poly- silicon emitter process technique, a set of optimized process for solving the key problem of the compatibility between switch and IC technique has been obtained, and the monolithic integration experiments of RF MEMS CPW switch and circuit has been done.