High-power up to 4 W characteristics of the capacitive microwave power sensor with grounded beam

摘要

The high-power up to 4 W characteristic of a capacitive microwave power sensor with grounded MEMS beam is investigated. This device is fabricated by GaAs MMIC (microwave monolithic integrated circuit) technology. Experimental results indicate that the sensitivity of power sensor gradually degenerates with input power increasing continually. The measurement results are divided into three regions: pre-saturated, saturated and over-saturated regions. The corresponding sensitivities are 0.95, 0.76 and 0.56 fF/W at 10 GHz, respectively. This effect is caused by the device's capacitive mismatch at high-power, and the modified formula is calculated in sections.