A Wireless Passive LC Resonant Sensor Based on LTCC under High-Temperature/Pressure Environments

Sensors

Li Qin¹  Dandan Shen¹  Tanyong Wei¹  Qiulin Tan¹  Tao Luo¹  Zhaoying Zhou²  Jijun Xiong¹ 

[1] Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China; E-Mails:;State Key Laboratory of Transducer Technology, Department of Precision Instrument and Mechanology, Tsinghua University, Beijing 10084, China; E-Mail:

关键词: LC resonant sensor;    DuPont 951 ceramic;    dielectric constant;    Young’s modulus;    compensation structure;   

DOI  :  10.3390/s150716729

来源: mdpi

【 摘 要 】

In this work, a wireless passive LC resonant sensor based on DuPont 951 ceramic is proposed and tested in a developed high-temperature/pressure complex environment. The test results show that the measured resonant frequency varies approximately linearly with the applied pressure; simultaneously, high temperature causes pressure signal drift and changes the response sensitivity. Through the theoretical analysis of the sensor structure model, it is found that the increase in the dielectric constant and the decrease in the Young’s modulus of DuPont 951 ceramic are the main causes that affect the pressure signal in high-temperature measurement. Through calculations, the Young’s modulus of DuPont 951 ceramic is found to decrease rapidly from 120 GPa to 65 GPa within 400 °C. Therefore, the LC resonant pressure sensor needs a temperature compensation structure to eliminate the impact of temperature on pressure measurement. Finally, a temperature compensation structure is proposed and fabricated, and the pressure response after temperature compensation illustrates that temperature drift is significantly reduced compared with that without the temperature compensation structure, which verifies the feasibility the proposed temperature compensation structure.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.