摘要
This paper presents a readout system for the passive pressure sensors which consist of a pressure- sensitive capacitor and an inductance coil to form an LC circuit. The LC circuit transforms the pressure variation into the LC resonant frequency shift. The proposed system is composed of a reader antenna inductively coupled to the sensor inductor, a measurement circuit, and a PC post-processing unit. The measurement circuit generates a DC output voltage related to the sensor＇s resonant frequency and converts the output voltage into digital form. The PC post-processing unit processes the digital data and calculates the sensor＇s resonant frequency. To test the performance of the readout system, a sensor is designed and fabricated based on low temperature co-fired ceramic （LTCC）, and a series of testing experiments is carried out. The experimental results show good agreement with the impedance analyzer＇s results, their error is less than 2.5%, and the measured values are almost insensitive to the variation of readout distance. It proves that the proposed system is effective practically.
This paper presents a readout system for the passive pressure sensors which consist of a pressure- sensitive capacitor and an inductance coil to form an LC circuit. The LC circuit transforms the pressure variation into the LC resonant frequency shift. The proposed system is composed of a reader antenna inductively coupled to the sensor inductor, a measurement circuit, and a PC post-processing unit. The measurement circuit generates a DC output voltage related to the sensor＇s resonant frequency and converts the output voltage into digital form. The PC post-processing unit processes the digital data and calculates the sensor＇s resonant frequency. To test the performance of the readout system, a sensor is designed and fabricated based on low temperature co-fired ceramic （LTCC）, and a series of testing experiments is carried out. The experimental results show good agreement with the impedance analyzer＇s results, their error is less than 2.5%, and the measured values are almost insensitive to the variation of readout distance. It proves that the proposed system is effective practically.
基金
Project supported by the National Basic Research Program of China(No.2010CB334703)
the National Natural Science Foundation of China(No.51075375)
