Far-field Techniques For Predicting Aircraft Antenna Coupling

Abstract

The analytical prediction of coupling between antennas is frequently time consuming and costly. The predictions are most challenging when the antennas operate at frequencies below 1 GHz and are located on surfaces that offer only limited ground plane area. This paper explores the limitations of using simple far-field, free-space transmission equations to predict the coupling between two helicopter-mounted antennas operating in the UHF band. Onaircraft antenna coupling measurements are compared to coupling measurements performed in an anechoic chamber and to antenna coupling values calculated using the simple far-field, free-space transmission equations.