A novel in-line frequency sensor based on coupling capacitance for X-band application

摘要

This paper presents a novel in-line frequency sensor, based on coupling capacitance, for X-band applications. The novel frequency sensor can achieve absolute frequency measurement with a simple structure and no DC power consumption. Fabrication of the frequency sensor is completely compatible with the GaAs monolithic microwave integrated circuit process. A well-designed metal-insulator-metal capacitor is employed to couple a certain percentage of incident power and a thermoelectric power sensor is used to measure the coupled power. The sensor design is guided by HFSS simulation and a lumped circuit model. The results validate the effectiveness of the simulation and model, and show relatively good performance of the frequency sensor with simple and reliable components. The net sensitivity of the frequency sensor is about 1.43 mV (W.GHz)(-1), and the measured S-11 and S-21 are better than -14.8 dB and -1.39 dB at X-band.