Closed Form Modal Green's Functions for Accelerated Computation of Bodies of Revolution

To solve problems of bodies of revolution (BoR) using the method of moments, the modal Green's function is used, which is defined as the radiation field of a circular loop antenna with sinusoidal current distribution. It is a group of oscillating integrals that forms the bottleneck for further accelerating the computation of BoR problems. In this paper, we propose closed-form expressions for near-axis far-distance modal Green's functions, which can be used to accelerate the computation of BoR problems especially when the object is slim. A criterion is presented based on a rigorous error analysis to guarantee its range of applications. Both the scattering and radiation examples are presented to demonstrate the validity and efficiency of the proposed expressions.