An Integrated Microwave Power and Frequency Sensor For 1–10 GHz Application

In this paper, an integrated sensor for microwave power and frequency measurement is proposed for 1-10 GHz application. The novelty is that this device cannot only measure microwave power but also can realize microwave frequency measurement at the same time. The incident power is dissipated and converted heat by two loaded resistors, and then detected indirectly by output voltage based on Seebeck effect. A microelectromechanical system (MEMS) coupler is designed over the coplanar waveguide transmission line and the coupled power varies with the frequency of the signal. Therefore, by measuring the coupled power, the frequency of the signal can be deduced. This integrated power and frequency sensor is fabricated by GaAs monolithic microwave integrated circuit process and MEMS technology. The measured return loss is about -26 dB at 1 GHz and -22 dB at 10 GHz. The power measurement indicates that the sensitivity is close to 0.116 mV/mW at 1 GHz and 0.110 mV/mW at 10 GHz. The frequency measurement is performed and the sensitivity is close to 0.035 mV/GHz under the incident power of 60 mW.