基于无源RFID的天线传感器的频率响应机理研究

发布时间：2018-10-11 17:53

【摘要】：结构健康监测(SHM),是一种自动监测结构健康状况的方法,它是保障结构安全的关键性技术之一。传统的健康监测方法,具有布设、维护费用高、安装复杂、需要人工操作等诸多缺点。本文旨在研究出一种无源、无线、可靠性高且低成本的RFID的应变传感技术。研究的方向为探究RFID天线应变频率响应机理。本文首先理论推导纵向应变过程,证明了微带天线谐振频率和应变之间存在良好的线性关系。利用HFSS建模,设计了微带线馈电和同轴线馈电的贴片天线,设计谐振频率为2.45GHz。通过纵向应变的仿真和实验,验证了微带贴片天线作为应变传感器的可能性。针对天线设计和实验过程存在的问题,论文提出了改进实验的方法。论文接着设计了一个带过孔的1/4波长的微带贴片天线。通过理论推导、建模仿真和实验,证明了微带天线的纵向应变灵敏度要远高于横向应变灵敏度。论文还详细分析了实验和仿真的灵敏度差异。通过传递效率测量实验,研究传递效率与应变的关系,修正了实验应变灵敏度;通过基于泊松效应进行应变仿真,修正了仿真应变灵敏度。最终确定应变传感器谐振频率偏移率和应变关系的灵敏度为-0.8652。为了推动天线应变传感器的实用化,本文设计了一种带过孔的同轴馈电的微带贴片天线。并设计了无线测量方案,研究测量距离与系统谐振频率的关系,确定了最佳的无线测量距离为6cm处。在测量距离为6cm处,进行了应变测量实验。实验的结果证明无线测量时,天线应变与谐振频率偏移率之间仍存在线性关系。
[Abstract]:Structural health monitoring (SHM),) is an automatic method for monitoring structural health. It is one of the key technologies to ensure structural safety. The traditional health monitoring method has many disadvantages, such as layout, high maintenance cost, complex installation, manual operation and so on. The purpose of this paper is to develop a passive, wireless, reliable and low cost strain sensing technique for RFID. The research direction is to explore the mechanism of strain frequency response of RFID antenna. In this paper, the longitudinal strain process is deduced theoretically, and it is proved that there is a good linear relationship between the resonant frequency and the strain of the microstrip antenna. A patch antenna with microstrip line feed and coaxial feed is designed by using HFSS model. The resonant frequency is 2.45 GHz. The possibility of using microstrip patch antenna as strain sensor is verified by simulation and experiment of longitudinal strain. Aiming at the problems in antenna design and experiment, the paper puts forward the method to improve the experiment. Then a 1 / 4 wavelength microstrip patch antenna with holes is designed. It is proved that the longitudinal strain sensitivity of the microstrip antenna is much higher than that of the transverse strain sensitivity through theoretical derivation, modeling, simulation and experiment. The sensitivity difference between experiment and simulation is analyzed in detail. The relationship between the transfer efficiency and the strain is studied and the strain sensitivity is corrected through the experiment of measuring the transfer efficiency, and the strain sensitivity is modified by the strain simulation based on the Poisson effect. Finally, the sensitivity of resonance frequency offset rate and strain relation of strain sensor is -0.8652. In order to promote the practical application of antenna strain sensor, a microstrip patch antenna with a coaxial feed through a hole is designed in this paper. A wireless measurement scheme is designed to study the relationship between the measurement distance and the resonant frequency of the system. The optimal wireless measurement distance is determined to be 6cm. Strain measurement experiments were carried out at 6cm distance. The experimental results show that there is still a linear relationship between antenna strain and resonant frequency offset in wireless measurement.
【学位授予单位】：上海应用技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.44;TN820

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