Temporal acceleration of time-domain integral-equation solvers for electromagnetic scattering from objects residing in lossy media

✍ Scribed by Pei-Lin Jiang; Eric Michielssen

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 178 KB
• Volume: 44
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.20595

✦ Synopsis

Abstract

The computational cost and memory requirements of classical marching‐on‐in‐time (MOT)‐based time‐domain integral‐equation (TDIE) solvers for analyzing scattering of electromagnetic waves from surfaces residing in lossy media scale as O(N____N) and O(N____N~t~), respectively; here, N~s~ and N~t~ are the number of spatial and temporal degrees of freedom of the surface currents. The quadratic dependency of these costs upon N~s~ and N~t~ prevents these methods from being applied to the analysis of large‐scale scattering phenomena. Here, an accelerator is proposed to improve the scaling of these TDIE solvers' computational complexity and memory requirements with N~t~. The accelerator casts temporal tails in convolutions of the lossy medium‐wave‐equation Green's function and TDIE solver temporal‐current basis functions in terms of a Prony series. This representation enables computation of the fields produced by surface currents within an MOT framework via recursive convolution. A technique that allows the reuse of Prony series poles for extended spatial interaction ranges, thereby greatly enhancing the scheme's efficacy, is proffered. The scheme's computational cost and memory requirements scale as O(N____N~t~log N~t~) and O(__N__log N~t~), respectively, with fairly small multiplicative factors. Besides being useful in the analysis of scattering from electromagnetically small objects residing in lossy backgrounds, the proposed scheme also constitutes a key building block in the construction of improved lossy‐medium plane‐wave time‐domain algorithms with efficient near‐field evaluation capability. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 223–230, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20595