Affiliation of Author(s):电子信息工程学院

Journal:2017 PROGRESS IN ELECTROMAGNETICS RESEARCH SYMPOSIUM - SPRING (PIERS)

Key Words:ELECTROMAGNETIC SCATTERING FINITE-ELEMENT

Abstract:Time-domain based electromagnetic (EM) field solvers choose electric and magnetic fields as their initial conditions which are the function of space and time. The variation of fields with respect to time in the computational domain is observed at some observation point and frequency response is obtained by using fast Fourier transformation (FFT). In order to perform broadband simulation up to the frequency of interest, the time domain signals must support the requisite spectrum coverage. This paper uses the standard theory of space decomposition in discontinuous Galerkin time domain (DGTD) method and analyses the effects of different types of sampling on spectrum coverage of gauss pulse. The computational domain is discretized into K number of nonoverlapping elements (known as h-refinement) and each element uses Nth order of polynomial interpolation (known as p-refinement). The interpolation is achieved by using Np number of interpolating nodes. The K elements can be uniform or nonuniform and the distribution of interpolating nodes inside each element can also be uniform or nonuniform. The combination of all these four schemes, i.e., i) Uniform h and uniform Np, ii) Uniform h and nonuniform Np, iii) Nonuniform h and uniform Np, and iv) Nonuniform h and nonuniform Np, have an effect on the sampling of the time-domain signal. This variation in the sampling rate of the time-domain signal causes variation in bandwidth coverage of the frequency-domain spectrum. The selection of suitable combination, defined by a different value of K and N, helps in the modeling of the excitation source for the DGTD based time-domain EM field solver. The Legendre-Gauss-Lobatto (LGL) nodes distribution is selected as nonuniform Np. After series of simulations, the best combination for the sampling of the time-domain source is selected to be the `Nonuniform h and nonuniform Np'. The variation in the bandwidth coverage of the spectrum is also studied with respect to the variation in the smallest size of an element. The higher coverage of bandwidth can be achieved only by changing few sampling points in nonuniform h and nonuniform Np.

Translation or Not:no

Date of Publication:2017-01-01

Co-author:Hussain, Ishfaq,Li, Huiping,cqs

Correspondence Author:cqs,WANG Yi