A HYBRID GENETIC-ALGORITHM SPACE-MAPPING METHOD FOR THE OPTIMIZATION OF BROADBAND APERTURE-COUPLED ASYMMETRICAL U-SHAPED SLOT ANTENNAS

In this study, a novel hybrid genetic-algorithm space-mapping method (GA-SM) is used in conjunction with method-of-moments (MoM) to design a broadband aperture-coupled asymmetrical U-shaped slot antenna. This hybrid method consists of the application of a genetic algorithm (GA) that employs coarse models in the simulations and an additional space mapping (SM) method that refines the solution found in the previous stage. As a comparison, the single application of GA with a fine model is also used to design the antenna. Compared with GA, the GA-SM method is much more efficient in reducing the computational time and can successfully achieve the same design goal as GA does. Finally, the proposed antenna is fabricated based on GA-SM optimization, and measured results show that the impedance bandwidth reaches 2.22GHz (2.23GHz-4.45 GHz) (VSWR < 2.0), which means that the relative impedance bandwidth is expanded up to 66.6%. Hence, GA-SM method is an efficient and practical technique for designing antennas, especially for large antenna array design in which long computational time is required.