Passive and Chipless Packaged Sensor for the Wireless Pressure Monitoring in Harsh Environment

A new millimetre-wave passive and chipless packaged sensor for wireless pressure monitoring in harsh environment is proposed. This sensor uses a planar microstrip resonator coupled with a high resistivity silicon membrane. The remote interrogation of this sensor is performed from a Frequency-Modulated Continuous-Wave (FMCW) radar. Prototypes have been designed and fabricated using photoresist intermediate layer for the silicon membrane bonding. Radar measurements on two sensors validate a 6dB full-scale response for 1.4 bar overpressure. Depression measurements demonstrate the transducer hermeticity and a measured sensitivity of 1.6% per bar on the millimetre-wave resonant frequency.