Characterization of MEMS sensor for RF Transmitted Power Measurement

In this report we introduce the procedure for performing a thermo mechanical design and analysis of thermal GaAs-based MEMS devices. It will provide the procedure how thermal analysis should be made and model equations used to describe conduction, convection, radiation and mechanical effects caused by nonhomogenous temperature distribution. This is demonstrated on the design of Micromechanical thermal converter (MTC) that creates heart of the RF power sensor microsystem. The conception of absorbed power measurement is based on thermal conversion, where absorbed RF power is transformed into thermal power, inside a thermally isolated system. The temperature changes induced in the MTC by electrical power dissipated in the HEMT (High Electron Mobility Tranzistor) are sensed using the temperature sensor. The temperature distribution, over the sensing area, and mechanical stress was optimized by studying different MTC sizes, and layouts of the heater and temperature sensor. Key-Words: Thermal Converter, Thermo-mechanical simulations, MEMS, Power sensor, GaAs microsystems