Optimisation of an unequally spaced dual-band printed base station antenna array using a marginal distribution technique

An efficient optimisation algorithm is presented for printed antenna design which aims to reduce the number of simulation runs required to find an optimal solution. Such efficiency is important in antenna design because of the high computational cost of each simulation run. The algorithm makes use of marginal distributions to guide the optimisation process, and its real-valued (rather than binary) representation of optimisation parameters makes it directly applicable to a wide range of antenna design problems. The particular application presented is for the design of an unequally spaced dual-band printed cellular base station array. The optimisation algorithm successfully chooses spacing and element length values for the array to meet radiation pattern requirements in both the GSM900 (880-960 MHz) and DCS1800 (1710-1880 MHz) bands. Theoretical results for the optimised printed wire array are compared with measurements.