Time-frequency processing of backscattered signal from a slotted waveguide array

Electromagnetic signals backscattered from targets provide information useful to classify and identify the targets. It was recently reported that the time-frequency processing of wideband backscattered signals gives us additional insights into the scattering physics of targets not available in either the time domain or the frequency domain alone. In the two-dimensional time-frequency plane, resonance frequencies, scattering centers and dispersive behavior can be clearly visualized simultaneously. The time-frequency analysis has already been applied to investigate the backscattering signals from grating structures. For 2-D finite dielectric gratings, it was shown that the Floquet frequencies due to the periodicity of the structure, the scattering centers due to the edges of the grating and the dispersive characteristics due to surface waves can be individually identified. In this work the backscattering from a 3-D rectangular slotted waveguide array will be analyzed by the use the short-time Fourier transform (STFT). The data, generated in the frequency domain, was obtained by the use of the moment method together with a connection scheme.<>