Effects of Introducing Confluence Rings on Ground Loss Resistance of VLF Umbrella-Type Antenna

Abstract

In this work, we analyze the influence of introducing confluence rings on the ground loss resistance in the ground grid system of the VLF umbrella-type transmitting antenna. The geometric deconstruction model of the confluence ring, the model of the VLF umbrella-type transmitting antenna, the models of the umbrella-type antenna ground grid system, and the formulae for the average conductivity are established. The working principle of the confluence ring was analyzed, and the ground loss resistance of the confluence ring structure with different numbers of layers and varying degrees of wire damage was simulated using Feko. The simulation results demonstrated the effect of increasing the number of confluence ring layers on the ground loss resistance of a fully functional grid to be relatively weak. However, when the ground grid wire is broken, the confluence ring structure can effectively reduce the ground loss resistance, thereby improving the radiation efficiency of the antenna.