Design and development of a millimetre-wave novel passive ultrasensitive temperature transducer for remote sensing and identification

The millimetre-wave passive temperature transducer consists of micro bimorph cantilevers (Au-Silicon) and split ring resonators, operating around 30 GHz. The temperature change causes a deflection on the bimorph cantilevers, thus results in a shift of resonant frequencies of the split ring structure. The design achieves sensitivity of 2.62 GHz/um in terms of frequency shift response to cantilever deflection, corresponding to a sensitivity of 498 MHz/°C, three order of magnitude higher than existing sensors. In terms of deflection versus temperature, the material choices for the bimorph cantilevers can be varied and adapted to different applications including those operating in harsh environments. To demonstrate proof-of-concept, a scaled prototype operating around 3 GHz is presented with Radar Cross Section measurements for remote identification.