Numerical analysis of helical antennas backed by finite ground planes

Abstract

A method of moments for arbitrarily shaped wire antennas with dielectric coating is developed. In this paper, we use this numerical method to investigate monofilar and quadrifilar helical antennas, whose wires are dielectric coated or not, backed by circular ground planes or cavities. Low-cost quadrifilar helical antennas that are printed on a thin dielectric substrate are also analyzed using this method. Indeed, the concept of equivalent radius is used to transform the printed wire antenna into an equivalent dielectric-coated wire structure. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 15: 352–355, 1997.