Accuracy of Sources and Near-Zone Fields When Using Potential Integral Equations at Low Frequencies

Gur U. M., Ergul O.

IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, vol.16, pp.2783-2786, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 16
  • Publication Date: 2017
  • Doi Number: 10.1109/lawp.2017.2746016
  • Journal Name: IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2783-2786
  • Keywords: Low-frequency problems, method of moments, potential integral equations (PIEs)
  • Middle East Technical University Affiliated: Yes

Abstract

We consider method-of-moments solutions of the recently developed potential integral equations (PIEs) for low-frequency electromagnetic problems involving perfectly conducting objects. The electric current density, electric charge density, and near-zone fields calculated by using PIEs are investigated at low frequencies, in contrast to those obtained via the conventional electric-field integral equation (EFIE). We show that: 1) the charge density can accurately be found by using EFIE despite the very poor accuracy in the current density; 2) using PIEs instead of EFIE leads to accurate computations of the dominating solenoidal part of the current density, while the vanishingly small irrotational part and the charge density become inaccurate; 3) it is possible to accurately compute the charge density, in addition to the current density, when using PIEs, but at the cost of a solution of an additional integral equation. Numerical examples involving spherical objects are presented to demonstrate the accuracy of sources and near-zone fields when PIEs and EFIE are used.