A capacitively-loaded MEMS Slot element for wireless temperature sensing of up to 300°C

In this paper we present a new slot antenna with an embedded temperature sensor for remote sensing in harsh environment applications. When the antenna is illuminated with a plane wave it returns a signal. The returned signal's frequency is modulated by the loaded capacitance formed by an array of MEMS bimorph (metal-dielectric) cantilevers. The MEMS cantilevers deflect downwards when the temperature is changed from 20degC to 300degC. As a result, the resonant frequency of the slot is linearly tuned from 19.45 to 19.30 GHz. The design yields a totally passive and integrated antenna/sensor. The MEMS fabrication is inherently robust, does not suffer from the creep or fatigue problems of traditional bimorph temperature sensors, and has a very high manufacturing yield, even in an academic clean room environment.