Optimum Functions for Radial Wires of Monopole Antennas with Arbitrary Elevation Angles

Abstract

Monopole antennas on the earth usually use ground screen with simple radial wires to improve their radiation performance. The number of radials,N, is usually considered a constant in the screen. This paper studies the effect of changing N and considering it as a function of distance, ρ, from the monopole using a simple and yet a fast method. The function N(ρ) is optimized for different beam angles of an HF monopoleantenna. The theoretical functions are converted to practical functions to be formed using meandered lines. Practicable calculated results are validated bymethod of moments. Furthermore it is shown that for low angle radiation aconstant N(ρ) with optimized radius of the ground screen is the best choice. The results can be used for higher frequencies, i.e. VHF and UHF frequency bands as well.