LC谐振传感器的信号检测系统研究

Signal Detection System of LC Resonant Sensors

根据LC谐振传感器互感耦合系统的理论模型,设计了一种LC谐振传感器信号检测系统。该系统包括模拟部分、数字部分以及解算方法。模拟部分是通过混频器提取谐振信息,再用低通滤波器(LPF)直流化输出信号以方便数据采集。数字部分是完成信号采集及传给上位机处理。解算方法是通过同步模拟部分的线性扫频源与数字部分的数据采集,实现从携带谐振信息的直流信号中获取谐振频率。实验结果表明:该系统能够完整获得LC谐振传感器的测试信号,其性能稳定,测量精度高,谐振频率测量误差小于3.5%。该系统有望运用于LC传感器信号无线测量的领域。

According to the theoretical model of the mutual coupling system for LC resonant sensors,a signal detection system for LC resonant sensors was designed. The signal detection system includes analog parts,digital parts and calculating methods. Analog parts extract resonance information via mixer,and transform output signal to dc signal with low pass filter（ LPF） which is convenient for data acquisition. Digital parts complete signal acquisition and transmit to PC for processing and analysis. Calculating method realizes obtaining resonance frequency from the dc signal of carrying resonance information by synchronizing linear sweep frequency source of the analog parts and the data acquisition of the digital parts. The experimental results prove that the signal detection system can obtain the LC resonant sensors＇ testing signal completely,it has stable performance and high accuracy,and the resonant frequency measurement error is less than 3.5%. The system can be applied to measure LC sensors＇ signal wirelessly.