Integrated passive wireless pressure and temperature dual-parameter sensor based on LTCC technology

This paper presents a kind of passive wireless pressure and temperature integrated inductor-capacitor (LC) resonant sensor based on low temperature co-fired ceramic (LTCC) technology. The pressure sensing part is dependent on a traditional cavity capacitor. The temperature sensing part is composed of an interdigital capacitor and a planar spiral inductor. The capacitance and the resistance of inductor coil would change as a response to temperature. The LTCC material with a low Young's modulus of ~65 GPa prepared by our laboratory was used to obtain high pressure sensitivity. The experimental results showed that the prepared sensor has a pressure sensitivity of 1.16 kHz/kPa, and a temperature sensitivity of 0.062% dB/°C within the range of 140–850 kPa, 50–500 °C, respectively.