Research Of Microstrip Antenna Miniaturization Using Genetic Algorithm

There are a good many actual significances for the miniaturization of microstrip antennas in the fields of modern communication, navigation, orientation, and electronic countermeasure, etc. The research and exploitation of compact antennas with high performance are becoming one of the hotspots in the antenna field. People have put forward many methods include using special material, special construction or affixing active electric network. Loading different shapes of slots in the patches of antennas will cut off the original surface current and the current has to flow around the slots that make its route longer. This course is equally satisfactory in result of inserting cascade inductances in the equivalent circuit of antenna. The narrow slot can simulate an infinite thin transverse magnetic wall in the patch, by the agency of which the relative electrical dimension of the effective part of radiation is enlarged.This paper discusses three slot-coupled microstrip antennas with high dielectric constants based on GPS (Global Positioning System) receiving antenna. They are separately with slots of oblique, T shape, and L shape. Antennas are simulated by CST MICROWAVE STUDIO. Measurement results are in good agreement with simulation results. The results indicate that slot-coupling could satisfactorily reduce antenna size.But it is tough to present a definite generalization to how exactly the slot size influences the radiation of microstrip antenna. Generally speaking, the increase of the slot length and width can make the resonance frequency low, which is not the longer the better, however. This paper design a kind of slot-coupled microstrip antenna using genetic algorithm combined within CST VBA MACRO Language environment which is used to optimize the slot size. A set of mezzo datum are obtained. The optimized antenna manifests its practicability.