Aperture-Shared All-Metal Endfire High-Gain Parabolic Antenna for Millimeter-Wave Multibeam and Sub-6-GHz Communication Applications

This communication demonstrates an endfire aperture-shared antenna for millimeter-wave (mm-wave) multibeam and sub-6-GHz communication applications. High-gains are achieved based on the parabolic reflectors (PRs) that can collimate the electromagnetic (EM) wave radiated from the feeds at the focal points. In contrast to the full metal-based PR in the sub-6-GHz band, the mm-wave PR is implemented using periodic metal gratings, which shows a bandgap in the mm-wave band while allowing the sub-6-GHz EM wave free to pass. In this way, the sub-6-GHz and mm-wave parabolic antennas share the same radiating aperture with near 100% aperture reuse efficiency and tiny mutual interference. Multiple mm-wave feeds are used to achieve multibeam radiation without a complicated feed network. The radiating aperture is gradually enlarged in a flared structure to enhance the gain further while maintaining a high aperture efficiency. In contrast to the state-of-the-art printed circuit board (PCB) designs, the proposed antenna is an all-metal one with the advantage of no dielectric loss. A prototype operating at the C- and Ka-bands is designed, prototyped, and measured.