Stacked patches using high and low dielectric constant material combinations

In this paper, the performance of stacked patches incorporating a high and low dielectric constant material combination is presented. Such a printed a ntenna is applicable for cases where photonic and microwave devices need to be directly integrated with the antenna. It will be shown that 10-dB retur n-loss bandwidths in excess of 25% can be achieved with such a configuratio n. Importantly, the surface wave efficiency across this band of frequencies is high-greater than 85%. It will also be shown that these stacked patches have lower crosspolarization levels compared to a conventional stacked pat ch and, thus, are very suited to circular polarization applications. Two ci rcular polarization (CP) configurations are presented and experimentally ve rified. The single- and dual-feed configurations have 3-dB axial ratio band widths of 18% and 32%, respectively.