基于RFID的微带天线应变传感器的仿真分析

为了研究应变传感器的无线检测技术,提出一种基于无线射频识别(radio frequency identification,RFID)微带天线应变传感器的无线检测方法,将超高频RFID技术与微带天线技术相结合,以微带天线作为标签天线,接收RFID阅读器发射的能量,激活RFID的标签芯片,芯片再通过信号调制技术,消除环境中的噪声干扰,并将天线谐振频率随应变变化信息返回阅读器,实现无源无线的应变检测.分别设计了插入馈电式和边缘馈电式2种RFID微带天线传感器,利用HFSS电磁仿真软件对二者进行了结构和参数优化设计;利用COMSOL仿真软件,通过固体力学和电磁学相耦合的仿真分析,明确了不同应变状态下,2种传感器谐振频率的偏移量与应变均呈线性关系,其仿真结果与理论值相吻合,满足结构应变测量的要求,为实验研究奠定了理论基础.

Simulation Analysis of a Microstrip Antenna Strain Sensor Based on RFID

In order to study the wireless detection technology of strain sensor. A microstrip antenna wireless strain sensor based on radio frequency identification (RFID) was proposed by using ultra high frequency RFID system through electromagnetic wave interaction. The microstrip antenna sensor,as a tag antenna,received the RFID signal,which activated the chip in RFID tag. The background noise can be eliminated by the signal modulation technology. Then, the effective signal returned to the antenna, and the deviation of the resonant frequency informed the reader of realizing the wireless passive strain detection. Two kinds of RFID microstrip antenna sensor, inserted-feeding type and edge-feeding type were designed. The operating gain,return loss and electric field strength were simulated and optimized by HFSS (high frequency structure simulator). Through the analysis of solid mechanics coupled with electromagnetics by COMSOL, the principle that the deviation of the resonant frequency was proportionally to the strain in these two types of sensors. The simulation results are consistent with the theoretical values, which can meet the requirements for structural strain measurement, and lay a theoretical foundation for experimental research.