Joint time-frequency interpretation of scattering phenomenology in dielectric-coated wires

The scattering phenomenology in dielectric-coated wire structure is investigated using the joint time-frequency processing of simulated and measurement data. The method of moments is applied to carry out the simulation. The computed results are compared to measured data in both the frequency and time domains. The scattering data are next analyzed in the joint time-frequency plane by using the short-time Fourier transform (STFT) technique to provide further insight into the scattering phenomenology. The dispersive Goubau mode excited along the coated wire can be clearly observed in the joint time-frequency plane. In addition, the time-frequency distribution series, which improves the resolution of the STFT while overcoming the cross-term interference problem of the Wigner-Ville distribution, is applied to better identify backscattering returns that are difficult to resolve in the joint time-frequency plane