INTRODUCTION TO CHARACTERISTIC MODES

• Published in: Electromagnetic Radiation, Scattering, and Diffraction
• Main Authors: Pathak, Prabhakar H, Burkholder, Robert J
• Format: Book Chapter
• Language: English
• Published: Wiley 2021
• Edition: 1
• Series: IEEE Press Series on Electromagnetic Wave Theory
• Subjects: Surface impedance; Shape; Scattering; Eigenvalues and eigenfunctions; Impedance; Manganese; Optical surface waves
• ISBN: 9781119810513; 1119810515
• DOI: 10.1002/9781119810544.ch13

The integral equation methods provide rigorous and robust solutions for antenna and scattering problems through numerical discretization of relatively arbitrary structures. This chapter provides the characteristic modes (CMs) from the electric field integral equation (EFIE) for a conducting surface. CMs, which are very similar to eigenmodes, are associated with an arbitrarily shaped surface. The CMs can be computed in order of significance without having to solve for all N eigenvectors. After finding the CMs from the discretized electric field operator, the EFIE may be easily solved in closed form using the orthogonality property. A set of CMs must be derived to adequately cover the band of interest. Antenna excitation is one of the primary uses of CMs in that virtually any shaped conductor can become an antenna. CMs are also useful for predicting the low‐frequency performance of electrically small antennas.