Visualizing and Controlling Coupling Paths Between Antennas Installed on Common Platforms

Abstract: In this work, a methodology to visualize and mitigate antenna coupling ina systematic way is proposed, which can be used to increase the isolationbetween dierent antenna systems installed on a common platform. Formulationsfor visualizing the coupling in space, based on reciprocity are derivedfrom the reaction theorem and the dierent formulations are compared witheach other through numerical simulations in CST Microwave Studio and bypost-processing in Matlab. The derived formulations are also compared witha more established method based on the Poynting vector.The ability of the derived formulations to predict appropriate positions forplacing absorbers is compared by introducing surface wave absorbing materials(SWAM), based on the visualization results. This is done for two simplied platforms with simple antennas to compare the dierent methods. Arealistic model consisting of a ground plane with cavities for integrating theantennas that could represent an integrated mast for naval ships is studiedwith the target to reduce the mutual coupling using the visualization methods.A cavity-backed spiral antenna and a body-of-revolution (BoR) arrayantenna are used as sources.One of the formulations derived from the reaction theorem performs well asa predictor for absorber placement and at several points better than existingmethods for the simplied platforms. This formulation can predict areaswhere placing an absorber will increase or decrease the coupling respectively.Furthermore, it is possible to estimate the impact of introducing an absorberin one region, relative to another. In the realistic case, it is demonstratedhow this formulation can be used to reduce the mutual coupling in a systematicand ecient way. It is shown that the isolation is increased with4{5 dB by placing SWAM at positions based on the visualization results,compared to covering the entire surface with SWAM.