Fast Analyses Of Radiation Characteristics Of Antenna On Complex Electrically-large Platforms Using PO Technique

Simulation of radiation characteristics and their electromagnetic compatibility of antennas mounted on electrically large and complex shaped platforms such as ships and satellites have attracted more and more attention in electromagnetics research and industry communities. It's very efficient to solve these EM problems by physical optics (PO) method. In this dissertation, a fast PO algorithm based on panel elements is developed and applied to the analyses of radiation performance of onboard antennas with the help of CAD modeling of 3-dimensional complex objects and surface automatic meshing technique. Based on traditional PO method and Green's function, an efficient approximate analytical formula is derived for the scattering fields of arbitrary polygon element. Using this formula, a great reduction of the computational time and memory cost, while maintaining or even improving the degree of accuracy, can be achieved. The identification of shaded surface elements is implemented for 3-dimensional complex platforms. In order to take advantage of PO algorithm and compensate its drawbacks, hybrid Huygens-PO and hybrid moment method-PO methods are developed and applied to analyze onboard aperture antennas and wire antennas. At last,the proposed PO algorithm is applied to platforms consisting of lossy panels, making the PO method applicable to more engineering electromagnetic problems. The radiation characteristics of a helix antenna on a satellite model and a parabolic antenna onboard a ship model are presented as numerical examples. The numerical results demonstrate that the proposed PO algorithm and its hybrid techniques are efficient and fast to analyze radiation characteristics of wire and aperture antennas on complex and electrically large platforms.