A novel MEMS double-channel microwave power sensor based on GaAs MMIC technology

Abstract

A novel MEMS double-channel microwave power sensor based on GaAs MMIC technology is presented in this paper. Compared with the traditional thermoelectric microwave power sensor, a cantilever beam is introduced and monolithically integrated as a capacitive microwave power sensor to enhance the measurement range and improve the overload capacity. The low microwave power is detected by the thermoelectric microwave power sensor, and the high microwave is detected by the capacitive microwave power sensor. The models of output voltage and capacitance change are built, and the cantilever beam is researched. This microwave power sensor is designed and fabricated using MEMS technology and GaAs MMIC process. With the microwave power range from 0.1 to 100mW, the sensitivity of thermoelectric microwave power sensor is about 0.117, 0.109 and 0.096mV/mW at 8, 10 and 12GHz, respectively. With the microwave power range from 100 to 200mW, the sensitivity of capacitive microwave power sensor is about 0.027, 0.024 and 0.022fF/mW at 8, 10 and 12GHz, respectively. Furthermore, in addition to enhanced measurement range and improved overload capacity, another significant advantage of this MEMS microwave power sensor is that it can be integrated with MMICs and other planar connecting circuit structures with zero dc power consumption.