Performance Improvement of a U-Slot Patch Antenna Using a Dual-Band Frequency Selective Surface With Modified Jerusalem Cross Elements

A dual-band FSS consisting of regular Jerusalem cross elements was first used to study its impact on the bandwidths and resonant frequencies of a U-slot patch antenna. Based on the simulation experience of the first partial study, another FSS with modified Jerusalem cross elements was proposed to improve the bandwidths, antenna gains, and return losses of a smaller U-slot patch antenna at 2.45 and 5.8 GHz for Bluetooth and WLAN applications, respectively. Measured data of the return loss, radiation pattern, and antenna gain of this smaller U-slot patch antenna were also presented. It is proven that the smaller U-slot patch antenna implanted with a FSS consisting of modified Jerusalem cross elements has a good performance with sufficient bandwidth and higher gain and is capable of dual-band operation.