Analysis of Time Transient EM Field Response from a Dielectric Spherical Cavity

Hiroshi SHIRAI  Eiji NAKANO  Mikio YANO  

IEICE TRANSACTIONS on Electronics   Vol.E75-C   No.5   pp.627-634
Publication Date: 1992/05/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Electromagnetic Theory
transient analysis,  dielectric sphere,  singularity expansion method,  wavefront expansion method,  FFT,  

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Transient responses by a dielectric sphere have been analyzed here for a dipole source located at the center. The formulation has been constructed first in the frequency domain, then transformed into the time domain to obtain for an impulsive response by two analytical methods, namely the Singularity Expansion Method and the Wavefront Expansion Method. While the former method collects the contributions around the singularities in the complex frequency domain, the latter gives us a result which is a summation of each successive wavefront arrivals. A Gaussian pulse has been introduced to simulate an impulse response result. The Gaussian pulse response is analytically formulated by convolving Gaussian pulse with the corresponding impulse response. Numercal inversion results are also calculated by Fast Fourier Transform Algorithm. Numerical examples are shown here to compare the results obtained by these three methods and good agreement are obtained between them. Comments are often made in connection with the corresponding two dimensional cylindrical case.