Genetic algorithms and method of moments (GA/MOM) for the design of integrated antennas

This paper introduces a novel technique for efficiently combining genetic a lgorithms (GA's) with method of moments (MoM) for integrated antenna design and explores a two example applications of the GA/MoM approach. Integral t o efficient GA/MoM integration is the use of direct Z-matrix manipulation ( DMM), In DMM a "mother" structure is selected and its corresponding impedan ce or Z-matrix is filled only once prior to beginning the GA optimization p rocess. The GA optimizer then optimizes the design by creating substructure s of the mother structure as represented by the corresponding subsets of th e original mother Z-matrix. Application of DMM with GA/MoM significantly re duces the total optimization time by eliminating multiple Z-matrix fill ope rations. DMM also facilitates the use of matrix partitioning and presolving to further reduce the optimization time in many practical cases. The desig n of a broad-band patch antenna with greater than 20% bandwidth and a dual- band patch antenna are presented as examples of the utility of GA/MoM with DMM, Measured results for the dual-band antenna are compared to numerical r esults. Excellent agreement between numerical and measured results is obser ved.