Pattern Analysis of Uniform Circular Array

Abstract

The radiation characteristics of a uniform circular array with linear centrally-fed dipole elements, used for smart antenna systems, are analyzed in this paper. The radiation patterns of the array and the gain of the array over a single element are derived based on the thin-wire model. Numerical simulations using the thin-wire model and the method of moments (MoM) have been conducted and compared for a half-wavelength dipole array. Simulations using the MoM demonstrate that the wire diameter of the elements has no significant effect on normalized azimuthal and elevation patterns for a given pattern design. Normalized azimuthal patterns by the thin-wire model and the MoM are in good agreement with each other, while normalized elevation patterns by the thin-wire model are inaccurate since mutual coupling is not considered in the model. Wire diameter affects the radiation resistance and thus determines the amplitude of the radiation field.