耦合系数对无线无源传感器信号读取的影响

摘要

The influence of coupling coefficient on signal readout of wireless passive sensor is investigated. By establishing the lumped circuit model of the coupling system,and analysis it theoretically,the formula of impedance on the antenna side is derived. MATLAB simulation is used to perform theoretical analysis,and results shows that the variation of resonance frequency of the sensor which is retrieved from the impedance parameters on the antenna side is influenced by coupling coefficient, and the results are verified by experiment. Theoretical analysis and experimental result shows that proper coupling coefficient should be chosen to obtain a better measurement sensitivity when design the coupling system for wireless passive sensor.%研究了耦合系数对无线无源传感器信号读取的影响。通过建立无线无源LC传感器的集总电路耦合模型，对其进行理论分析，推导出了天线端阻抗参数的理论表达式，结合MATLAB软件仿真，从理论上得出，通过天线端阻抗参数提取出来的传感器谐振频率变化量受耦合系数的影响，并得到实验验证。理论分析和实验测试表明，在进行无线无源传感器耦合系统设计时，应选取合适的耦合系数，来提高测量灵敏度。