We report on time–frequency analysis (TFA) of dispersion in a 1-D magneto-inductive waveguide (MIW). The short-time Fourier transform (STFT) and Wigner–Ville distribution (WVD) are used to localize the frequency content of the dispersed wave as a function of time and to estimate the group velocity in experiments using a 1-D MIW constructed with planar resonators. Time-domain reflectometry (TDR) measurements are performed after deliberately introducing defects along the waveguide; and the results are analyzed with TFA, demonstrating the potential for using such MIW-TDR configurations as sensors. The WVD-TFA is shown to provide precise time–frequency information, accurate defect localization, and group velocity estimation, confirming the slow wave long-range nature of dispersive MIWs. The adaptability of the MIW-TDR setup and the accuracy of the WVD for localization make the technique a suitable candidate for sensing applications using engineered dispersive media.

中文翻译：

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磁感应波导中的群速度估计和缺陷定位

我们报告了一维磁感应波导（MIW）中色散的时频分析（TFA）。短时傅立叶变换（STFT）和Wigner-Ville分布（WVD）用于定位随时间变化的分散波的频率含量，并在使用平面构造的一维MIW的实验中估算群速度谐振器。在沿着波导故意引入缺陷之后，进行时域反射法（TDR）测量；并且使用TFA对结果进行了分析，证明了将MIW-TDR配置用作传感器的潜力。显示出WVD-TFA可提供精确的时频信息，精确的缺陷定位和群速度估计，从而确认了弥散MIW的慢波远距离特性。