A Hybrid Framework for Antenna/Platform Analysis

Abstract

Hybrid combinations of numerical and asymptotic methods are utilized to evaluate in-situ antenna performance, and coupling to other systems on a shared platform such as a ship topside. This paper describes a combination of the finite element-boundary (FE-BI) method with ray techniques for evaluating antenna patterns in the presence of complex platforms. Specifically, a very complex array antenna may be modeled with FE-BI, and interfaced to the platform via the use of equivalent currents. For the case considered here, the FE-BI is accelerated with the array decomposition fast multipole method (AD-FMM) so that large arrays may be considered. A novel discrete Fourier transform method is also introduced to provide a greatly reduced representation of the fields over a planar array aperture and the uniform theory of diffraction (UTD) along with iterative physical optics (IPO) are used to characterize the platform. To tie it all together, a matrix framework is formulated to iteratively increment the higher order interactions between antennas and platform.