This paper presents a capacitive displacement sensor based on a capacitively fed inverted-F antenna (CFIFA) for displacement detection. The sensor is composed of a grounded L-shape patch and a rectangular upper patch, forming a capacitor between them. The asymmetric dipole model is adopted to explain the frequency shift and current distribution of the proposed antenna sensor at its first-order resonance. The numerical simulation of the CFIFA using the Ansoft high-frequency structure simulator (HFSS) software is carried out to optimize the dimensional parameters, allowing the antenna to perform better. Two sets of CFIFAs are fabricated and tested for verification. Results show that the CFIFA has a good linear relationship between its first resonant frequency and the relative displacement, and is capable of a long range of displacement measuring.

中文翻译：

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在结构健康监测中用于位移检测的电容馈电倒F天线。

本文提出了一种基于电容式倒F天线（CFIFA）的电容式位移传感器，用于位移检测。该传感器由接地的L形贴片和矩形的上贴片组成，在它们之间形成电容器。采用非对称偶极子模型来解释所提出的天线传感器在一阶谐振时的频移和电流分布。使用Ansoft高频结构模拟器（HFSS）软件对CFIFA进行了数值模拟，以优化尺寸参数，从而使天线性能更好。制作了两组CFIFA并进行了测试以进行验证。结果表明，CFIFA在其第一共振频率和相对位移之间具有良好的线性关系，并且能够进行长距离的位移测量。