16-Port Cavity-Backed Aperture-Coupled Patch Antenna for On-Antenna Power Combining

This article proposes a novel multiport antenna topology aimed at enhancing on-antenna power combining (OAPC) capabilities. Leveraging the degenerated TE120 and TE210 sub-modes of a cavity-backed (CB) slot antenna, this design allows highly efficient feeding through the utilization of numerous ports (>8). In comparison to on-circuit power combining at the monolithic microwave integrated circuit (MMIC) level, this approach achieves improved efficiency, higher transmitted power, reduced MMIC size, and enhanced heat dissipation. To validate the concept, up to eight pairs of differential feedings (16 ports) are integrated into a polarization versatile antenna. Linearly polarized differentially fed antennas with 2, 4, and 16 ports are experimentally designed and fabricated for operation in S-band for comparison. Large-signal results demonstrate a notable +9 dB increase in radiated power for the active 16-port configuration compared to the active 2-port configuration, showcasing the promising OAPC capabilities. The proposed structure is anticipated to be highly valuable for active antenna arrays in radar and telecommunication applications.