60-GHz wideband branchline coupler and patch antenna with dielectric rod for full-duplex gigabit wireless communication

An improved design of the patch antenna with the dielectric rod is proposed. The wideband branchline coupler and wideband patch antenna are designed and optimized to realize a high port-to-port isolation for the whole 60-GHz ISM frequency band. In this paper, the design of the improved dielectric rod antenna is explained. The achieved gain of the antenna system is around 13.5 dBi, and the antenna supports dual circular polarization for bi-directional communication while promotes rotational freedom. The achieved port-to-port isolation larger than 20 dB is obtained for the bandwidth of 7 GHz, which is a significant improvement from the author's previous design. The measured axial ratio in the bandwidth of interest is below 3 dB.