Finite-Element Time-Domain Analysis of Electrically and Magnetically Dispersive Periodic Structures

• Published in: IEEE transactions on antennas and propagation Vol. 56; no. 11; pp. 3501 - 3509
• Main Authors: Riley, D.J., Jian-Ming Jin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; Boundary conditions; Broadband antennas; Couplings; Dispersion; Dispersive media; Equations; Finite difference method; Finite element method; Finite element methods; Magnetic analysis; Magnetic fields; Magnetic materials; Magnetic permeability; Mathematical analysis; Mathematical models; Periodic structures; Time domain analysis
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2008.2005454

A formulation is presented for the finite-element time-domain (FETD) analysis of periodic structures that contain electrically and/or magnetically dispersive materials. The formulation is based on the previously developed transformed field variable approach and the Floquet absorbing boundary condition, which are both applicable to arbitrary scan or incident angles. The paper describes an implicit finite-element time-marching equation for the transformed electric field variable coupled with a finite-difference type equation for the evaluation of the transformed magnetic field variable. The technique is applicable to general dispersive materials, although the required convolution calculations can be greatly accelerated when the electric and magnetic susceptibilities can be represented by a pole expansion. Numerical examples are presented to demonstrate the validity and capability of the proposed numerical approach which is effective for the efficient broadband analysis of complex periodic structures such as engineered materials and phased-array antennas.