An integrated microwave power and frequency sensor based on GaAs MMIC process and MEMS technology

In this paper, a novel integrated sensor for microwave power and frequency measurement is proposed for 1-10GHz application. In this device, the incident power is dissipated to heat by loaded resistors, and then detected indirectly by output voltage based on Seebeck effect. A MEMS coupler is designed over the CPW 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 MMIC process and MEMS technology. The measured return loss is -26dB at 1GHz and -22dB at 10GHz. The power measurement indicates that the sensitivity is close to 0.116mV/mW at 1GHz and 0.110mV/mW at 10GHz. The frequency measurement is performed and the sensitivity is close to 0.035mV/GHz under the incident power of 60mW.