Characterization of packaged inline-type radio frequency microelectromechanical systems power sensors

This paper proposes the characterization of 8-10 GHz inline-type radio frequency microelectromechanical systems (RF MEMS) power sensors on the packaging-test-fixture for power self-detection systems in RF receivers and transmitters. The sensors are used to convert a certain percentage of the RF power coupled by a MEMS membrane into thermovoltages based on Seebeck effect. Two packaging methods are studied to evaluate the RF performance by the simulation and the measurement. The effects of the temperature from 5 °C to 75 °C on the packaged power sensors are quantified by the measurement of the output thermovoltages, which result in the 33.2% change in sensitivity at 10 GHz. After the packaging, rise and fall response times of <10 ms are obtained. In addition, measured mechanical resonance frequency (f1st) of the MEMS membrane in the sensors is 78 kHz. Experiments show that the single-sideband phase noise of the packaged power sensors is as low as −122 dBc/Hz at the offset frequency Δf = 500 kHz for an input RF signal of 100 mW and 9 GHz, and the sensors do not generate any significant phase noise in the interested RF range.