High temperature characteristic for wireless pressure LTCC-based sensor

The high temperature characteristic for pressure sensor based on low-temperature co-fired ceramic (LTCC) technology is researched. The Young’s modulus of LTCC DuPont 951 ceramic versus temperature is analysed theoretically. The sensor resonant frequency is tested from room temperature to 600 °C. Results show that resonant frequency drops nearly as a line. And the dropping of resonant frequency is mainly caused by the increase of LTCC material permittivity. A capacitor structure is proposed to reduce the change of frequency versus temperature and a compensation structure is proposed for the actual application. Moreover, the coupling effect between antenna and sensor fabricated using FERRO A6M-E and DuPont 951 is compared at 600 °C. Result shows that the material with lower dielectric loss and thermal conductivity is suggested to increase the temperature range of operation of sensor.