Abstract

Electronic Warfare (EW) tactics seek to obtain control of the electromagnetic (EM) spectrum to disrupt the performance of enemy systems that use electronic sensing devices to operate. One of the passive tactical measures used are electronic support measure (ESM) systems, comprised of antennas that are installed on a naval, avionics or terrestrial platforms and which analyse incoming radio frequency (RF) pulses to provide the direction of arrival (DoA) and other characteristics of the received electromagnetic waves. However, EM interactions with the platform can create deformations in the shape of the antenna’s radiating beam, resulting in both amplitude and phase unbalances between the independent channels of the receiver, thereby reducing the accuracy of the estimation. It is therefore fundamental to evaluate these pattern deformations during design and this is most commonly done using specific EM solvers. The large dimensions of the platform on which the antenna is installed relative to the wavelength means that full-wave solvers and required to solve linear algebraic systems involving many millions of unknowns, dramatically increasing the computational burden.

This article discusses the use of the Ansys HFSS SBR+ method for wave propagation analysis that is based on specific EM propagation formulations (commonly referred to as Asymptotic Methods), and which offers an effective alternative in terms of solution accuracy and computational cost. The method’s effectiveness is demonstrated in this case study that considers the analysis of an ESM sinuous antenna installed on an avionics platform.