论文标题
电磁学的Wigner-Smith时间延迟矩阵：辐射和散射分析的计算方面
Wigner-Smith Time Delay Matrix for Electromagnetics: Computational Aspects for Radiation and Scattering Analysis
论文作者
论文摘要
WS时间延迟矩阵将无损和倒数系统的散射矩阵与其频率导数联系起来，并可以合成与系统交互时经历明确定义的组延迟的模式。 WS时间延迟矩阵的元素用于表面散射器和天线的元素包含涉及电气和磁场的重新归一化的能量样的体积积分，这些音场在通过其端口激发系统时会产生。在这里，提出了用于计算WS时间延迟矩阵的直接和间接方法。直接方法，使用表面积分算子评估了能量积分的积分，该表面积分算子对入射电场和电流密度作用，以表征散射矩阵的所有激发。间接方法通过计算散射参数及其频率导数来完成相同的任务。两种方法都在计算上有效，并且很容易整合到现有的表面积分方程代码中。所提出的技术有助于评估天线阻抗，天线模式和散射器雷达横截面的频率衍生物，该横截面是根据源自系统的单个频率表征得出的重新归一化场能的评估。
The WS time delay matrix relates a lossless and reciprocal system's scattering matrix to its frequency derivative, and enables the synthesis of modes that experience well-defined group delays when interacting with the system. The elements of the WS time delay matrix for surface scatterers and antennas comprise renormalized energy-like volume integrals involving electric and magnetic fields that arise when exciting the system via its ports. Here, direct and indirect methods for computing the WS time delay matrix are presented. The direct method evaluates the energy-like volume integrals using surface integral operators that act on the incident electric fields and current densities for all excitations characterizing the scattering matrix. The indirect method accomplishes the same task by computing scattering parameters and their frequency derivatives. Both methods are computationally efficient and readily integrated into existing surface integral equation codes. The proposed techniques facilitate the evaluation of frequency derivatives of antenna impedances, antenna patterns, and scatterer radar cross sections in terms of renormalized field energies derived from a single frequency characterization of the system.
