Time domain integral equation method using FFT-based marching-on-in-degree method for analyzing PEC patches on substrate (invited)

One time domain method, based on the TDIE solved by the marching-on-in-degree (MOD) scheme, is presented in this paper for capturing transient electromagnetic responses of dielectric-metallic composite structures. For perfect electrically conducting (PEC) surfaces patched on the dielectric substrate, the time-domain electric field integral equations (TD-EFIE) is used to analyze PEC patch, while PMCHW (Poggio, Miller, Chang, Harrington and Wu) integral equation is utilized for describing the dielectric substrate. The whole set of integral equations is solved simultaneously, and the temporal basis function is chosen to be the Laguerre polynomials (LP), which is called marching-on-in-degree scheme. For the spatial basis function, the classical RWG basis function is usually the suitable choice. Since in the right-hand-side of the iteration equation, during the matrix-vector multiplication, the impedance matrix has the form of Toeplitz matrix, the fast Fourier transform (FFT) can be used to accelerate this multiplication. Numerical results are given to demonstrate our proposed method used for analyzing characteristics of structures containing PEC patch on the substrate.