Improved Dynamic Range of Microwave Power Sensor by MEMS Cantilever Beam

This letter reports a microwave power sensor with improved dynamic range based on MEMS cantilever beam. The proposed power sensor is manufactured using GaAs microwave monolithic integrated circuit (MMIC) technology. In this design, a cantilever by-pass coupling structure is adopted for high power detection, while the terminating thermoelectric sensor is utilized for low power detection. The novelty of the proposed device is that the concatenation of a cantilever beam and the thermoelectric sensor allows the ultra-high dynamic range power detection. Measurement results show that the sensitivities are 0.0315, 0.0261, and 0.0237 mV/mW at 1, 2, and 3 GHz for input power from 0.1 to 100 mW, respectively. For input power from 100 mW to 1W, the sensitivities are 2.398, 3.753, and 5.416 μV/mW at 1, 2, and 3 GHz, respectively. This compact power sensor has the potential prospect for dynamic range application.