Implementation of the periodic boundary condition in the finite-difference time-domain algorithm for FSS structures

Author

Harms, Paul ; Mittra, Raj ; Ko, Wai

Author_Institution

Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA

Volume

42

Issue

9

fYear

1994

fDate

9/1/1994 12:00:00 AM

Firstpage

1317

Lastpage

1324

Abstract

A method for implementing the general Floquet boundary condition in the finite-difference time-domain algorithm (FDTD) is presented. The Floquet type of phase shift boundary condition is incorporated into the time-domain analysis by illuminating the structure with a combination of sine and cosine excitations to generate a phasor representation of the solution at each time step. With this approach, the characteristics of periodic structures comprised of arbitrarily shaped inhomogeneous geometries can be computed for an arbitrary angle of incidence. Theoretical results are compared for various planar frequency selective surfaces (FSS) and for one with a three-dimensional element, e.g., a thick, double, concentric square loop

Keywords

antenna theory; boundary-value problems; electromagnetic wave scattering; finite difference time-domain analysis; EM wave scattering; FSS structures; angle of incidence; arbitrarily shaped inhomogeneous geometries; cosine excitation; double concentric square loop; finite-difference time-domain algorithm; general Floquet boundary condition; periodic boundary condition; phase shift boundary condition; phasor representation; planar frequency selective surfaces; sine excitation; three-dimensional element; time-domain analysis; Boundary conditions; Computational geometry; Finite difference methods; Frequency selective surfaces; Optical design; Optical filters; Optical scattering; Periodic structures; Shape; Time domain analysis;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/8.318653

Filename

318653