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 antenna is applicable for cases where photonic and microwave devices need to be directly integrated with the antenna. It is shown that 10-dB return-loss bandwidths in excess of 25% can be achieved with such a configuration. Importantly, the surface wave efficiency across this band of frequencies is high-greater than 85%. It is also shown that these stacked patches have lower cross-polarization levels compared to a conventional stacked patch and, thus, are very suited to circular polarization applications. Two circular polarization (CP) configurations are presented and experimentally verified. The single- and dual-feed configurations have 3-dB axial ratio bandwidths of 18% and 32%, respectively