Broadband Stacked Microstrip Antenna with Genetically Designed Patches

This paper presents the broadband performance and broadside radiation of a stacked microstrip antenna design. This antenna consists of two substrates stacked one over the other incorporating an air gap in between. The substrates have ϵ r = 4.4 (dielectric constant) and h = 1.58 mm (height). One patch of the antenna has been designed to resonate at a frequency of 5 GHz. Genetic algorithms (GA) have been used to select the dimensions of the other patch in order to have broadband performance. Moreover, two slots have been cut on patches to improve performance further. The dimensions and the positions of the slots, the position of the feed, and the size of the air gap have also been optimized by using GA. The novelty of this antenna design is synchronized GA-based optimization of useful parameters. This optimized design has a −10 dB bandwidth of 3.4 GHz and broadside radiation with gain about 5 dB throughout the bandwidth. Its performance has been compared with stacked microstrip antennas that have not been optimized.