A High-Performance Dual-Channel MEMS Microwave Power Sensor With Cantilever Beam

In order to optimize the sensitivity and overload power of microwave power sensor, a dual-channel MEMS microwave power sensor with cantilever beam is proposed in this article. GaAs monolithic microwave integrated circuit (MMIC) process and MEMS technology are used for design and manufacturing. The theoretical model of MEMS dual-channel microwave power sensor with cantilever beam is established. The influence of the size of the cantilever beam on the microwave performance, overload power, and sensitivity of the sensor is studied. The microwave performance and sensitivity of three sensors with different cantilever beam sizes were tested. At 8–12 GHz, the return losses of three sensors are −10.6 to −57.2 dB at 200- $\mu \text{m}$ beam length, −10.6 to −62.4 dB at 300- $\mu \text{m}$ beam length, and −12.0 to −62.3 dB at 400- $\mu \text{m}$ beam length. They all show good microwave performance. At 10 GHz, the sensitivities of capacitive detection channel of three sensors are 16.3, 65.6, and 144.4 fF/W. Also, the sensitivities of thermoelectric detection channel are 142.3, 109.5, and 82.9 mV/W. The sensitivities of dual-channel MEMS microwave power sensors with cantilever beam are improved compared with the traditional microwave power sensor, which has a certain reference value for the design of MEMS microwave power sensors.