Multiband single-layer frequency selective surface optimized by genetic algorithm with geometry-refinement technique

We have developed the multiband single-layer FSS by using the optimization design technique based on the GA into which the geometry refinement method is incorporated. This method can remove the critical points which means that the adjacent conductor plates touch at a point, so that the designed FSS without the point contact of the conductor can be easily fabricated. Furthermore, we have show that the present method can obtain the optimum FSS element shape faster than the conventional GA technique by the natural selection. As a example. we design the FSS for transmitting 1.5/2.5 GHz band and reflecting 20/30 GHz band. The designed FSS has the novel element shape, which causes the dual-resonant behavior. The characteristics of the designed FSS are superior to those of the previous FSS in the bandwidth at two reflection bands. The agreement between the calculated and measured transmission responses for the designed FSS proves the validity of the present method.