A Novel Interdigital Capacitor Pressure Sensor Based on LTCC Technology

A novel passive wireless pressure sensor is proposed based on LTCC (low temperature cofired ceramic) technology. The sensor employs a passive LC circuit, which is composed of a variable interdigital capacitor and a constant inductor. The inductor and capacitor were fabricated by screen-printing. Pressure measurement is tested using a wireless mutual inductance coupling method. The experimental sensitivity of the sensor is about 273.95 kHz/bar below 2 bar. Experimental results show that the sensor can be read out wirelessly by external antenna at 600°C. The max readout distance is 3 cm at room temperature. The sensors described can be applied for monitoring of gas pressure in harsh environments, such as environment with high temperature and chemical corrosion.