Accurate Evaluation of Green's Functions for a Lossy Layered Medium by Fast Extraction of Surface- and Leaky-Wave Modes

作者：Song Zhe^*; Zhou Hou Xing; Zheng Kai Lai; Hu Jun; Li Wei Dong; Hong Wei

来源：IEEE Antennas and Propagation Magazine, 2013, 55(1): 92-102.

• Surface wave modes
• leaky wave modes
• discrete complex image method
• consecutive perturbations
• steepest descent path
• continuous spectrum
• Riemann sheet
• lossy media
• layered media
• electromagnetic theory

In this paper, a method based on consecutive perturbation for the fast and accurate extraction of all useful surface- and leaky-wave modes for a lossy layered medium is proposed. The algorithm consists of two perturbation stages. In the first stage, according to the relationship for the frequency variation between the surface- and leaky-wave modes, the leaky-wave modes for a lossless medium can be tracked by consecutive frequency perturbation, with the surface- wave modes at a proper high frequency as starting points. All the surface- wave modes are extracted by a modified dichotomy method. In the second stage, a consecutive loss perturbation is performed, in which the medium's loss is increased step by step. In each perturbation step of both of the two stages, Newton-Raphson iterations are employed to update the modes on the corresponding Riemann sheet. With these discrete modes accurately extracted, a combination of the Discrete Complex-Image Method (DCIM) and the All-Modes Method can be realized for accurate evaluation of the Green's functions in the near-field and non-near-field regions, respectively. Several numerical examples demonstrated the high accuracy and efficiency of this method.

• 出版日期2013-2
• 单位东南大学