三线圈式无源电子标签质量参数检测技术研究

Research on Quality Parameters Detection of Passive Electronic Label Using Three-Coil

电子商品防盗系统(EAS)中的无源电子标签工作原理可等效为LCR串联电路,其谐振频率FX和品质因素Q是无源电子标签关键质量参数。针对目前二线圈式检测方法检测此类标签参数存在的不足,设计一种差分式三线圈传感探头,分析了三线圈传感探头的工作原理,并采用Proteus软件对此传感探头的等效电路模型仿真,验证测量方法的可行性。同时设计了以MSP430F149处理器为核心的检测硬件电路,并基于二分法设计了快速寻找FX和Q值的跳频程序。以58 k Hz声磁无源电子硬标签为测试对象,试验表明:此检测技术的FX、Q值测量的绝对误差分别小于9.1 k Hz和1.0,其性能优于市售EAS频率检测仪(E-X5006AM)。

The principle of passive electronic tags in electronic goods anti-theft systems（ EAS） can be equivalent to LCR series circuits whose resonant frequency FXand quality factor Q are the key quality parameters of passive electronic tags. Aiming at the shortcomings of the current two-coil detection method to detect such tag parameters,a three-coil sensor probe structure is designed. The working principle of the three-coil sensing probe is analyzed,and the equivalent circuit of the sensor is adopted by Proteus software Model simulation,verify the feasibility of the measurement method. At the same time,the detection hardware circuit with MSP430 F149 processor is designed,and the hopping-frequency program of FXand Q is designed based on dichotomy. The experimental results show that the absolute error of FXand Q value measurement is less than 9.1 kHz and 1.0,respectively. The performance is better than that of commercial EAS frequency detector（ E-X5006 AM）.