In this paper, a genetic algorithm (GA) is
used to synthesize and optimize the excitation weights of
a planar array for satellite communications based on ITU
Radio Regulations 2016. The planar array is arranged
into symmetric square lattices of subarrays. Each subarray
is assumed to be consisting of 4×4 isotropic, uniform-
spaced, and uniform-weighted elements. The proposed
arrays are assumed to be consisting of 4×4 and 16×16
subarrays. A genetic algorithm is used to optimize the
weights at the subarrays. Three different cases are
studied in the paper. The first case is dealing with an
amplitude-only weighting synthesis of the planar array.
In this case the ratios of amplitude weights of subarrays
are varied continuously from 0 to 1. In the second case,
a phase-only synthesis of the planar array is discussed
where the phases are varied in a continuous range between
-π/2 and 0° while the amplitudes of all subarrays are the
same. In the third case a complex weight synthesis is
presented. In this case the ratios of the amplitudes are
constrained between 0.7 and 1 whereas the phases are
varied continuously from -π/2 to 0°. Moreover, the
amplitude is varied with both continuous and discrete
values. A comparison between the three methods is
presented to develop the optimum technique for feeding
an antenna array for satellite communication systems. |
