Thermally Isolated MEMS Thermo Converter for RF Power Sensor

This report discusses the design of Thermo-mechanical converter 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. Micromechanical Thermal Converter (MTC) spatial temperature dependences, thermal time constant and power to temperature characteristics are calculated from the heat distribution. 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