Title :
Dispersive modes in the time domain: analysis and time-frequency representation
Author :
Carin, L. ; Felsen, L.B. ; Kralj, D. ; Pillai, S.U. ; Lee, W.C.
Author_Institution :
Dept. of Electr. Eng., Polytechnic Univ., Brooklyn, NY, USA
Abstract :
Four algorithms for time-frequency (TF) distributions are considered for the processing and interpretation of dispersive time-domain (TD) data: the short-time Fourier transform, frequency and time-domain wavelets, and a new ARMA-based representation. The TF resolutions of the various distributions are discussed and compared with reference to results for the scattered fields from a chirped finite grating excited by a pulsed plane wave. The processing in the TF phase space extracts TD phenomenology, in particular the instantaneous dispersion relation /spl minus/ with its associated time-dependent frequencies-descriptive of the local TD Floquet modes on the chirped truncated grating.<>
Keywords :
Fourier transforms; dispersion (wave); electromagnetic wave scattering; time-frequency analysis; wavelet transforms; ARMA-based representation; Floquet modes; chirped finite grating; dispersive modes; dispersive time-domain data; frequency-domain wavelets; instantaneous dispersion relation; pulsed plane wave excitation; scattered fields; short-time Fourier transform; time-domain wavelets; time-frequency distributions; time-frequency representation; Algorithm design and analysis; Chirp; Dispersion; Frequency synthesizers; Gratings; Light scattering; Physics; Time domain analysis; Time frequency analysis; Wires;
Journal_Title :
Microwave and Guided Wave Letters, IEEE
