Multi-objective optimization for efficient end-fire superdirective array design

This paper presents a simple multi-objective optimization procedure, for efficient end-fire superdirective array design. The proposed method includes simultaneously the array directivity as well as its radiation efficiency in the optimization process. The proposed method, is used afterwards to design a three electrical dipoles based array operating at 780 MHz, for various separation distances in the range
$[0.03\lambda, 0.2\lambda]$
. At
$0.05\lambda$
, the antenna array presents a maximal directivity of 7.3 dBi, which is still 0.5 dB above the Harrington limit, a radiation efficiency of 99% and an IEEE gain of 7.2 dBi. To avoid using a feeding network, a parasitic array was formed where the second element is excited while the first and the third ones are loaded. The parasitic antenna exhibits practically the same results as the fully driven case.