Fast Radiation Pattern Synthesis and Optimization of Monopole Circular Antenna Array

The synthesis and optimization of the radiation pattern of a monopole circular antenna array are described. The method is fast and effective since it employs impedance and radiation pattern matrices, which relate elements of the array, precalculated in a full-wave electromagnetic simulator. A simple excitation by only the central element is used, and the other elements are reactively loaded. The desired radiation pattern of the array is obtained by optimization of the reactive loads. A particular example is given for a circular array of 25 monopole elements.

I. Introduction

The optimization of the radiation patterns in electromagnetic field simulators is generally limited to parameters such as directivity or efficiency, but one cannot specify an arbitrary shape of the desired radiation pattern. Moreover, optimization usually takes a long time, because for every iteration, a full-wave analysis must be performed.