Optimization of broadband antenna elements in a periodic planar infinite array

It is critically important that mutual coupling effects be properly taken into account when designing wideband antenna elements for use in phased arrays; especially those which require large scanning volumes. In this paper, a method of designing antenna elements for use in large planar phased arrays is presented. The geometric and electrical properties of a single antenna element in an infinite array environment are optimized so that the mutual coupling between the array elements can be properly accounted for. A robust genetic algorithm is used to optimize the antenna elements for operation in an infinite array environment with the goal of providing low return loss, high gain, and linear polarization over wide operating bandwidths and large scan angles. A periodic finite element boundary integral code has been developed and is employed here as the simulation tool of choice for efficient analysis of infinite periodic antenna arrays.