Fully Metallic Dual-Band-Multibeam Aperture-Shared Lens Antenna for N257 Millimeter-Wave and N79 Sub-6 GHz Applications

This article demonstrates a dual-band aperture-shared wide-angle multibeam lens antenna for the N257 millimeter-wave (mmW) and N79 sub-6-GHz applications. The key novel contributions of this article include: 1) a new antenna structure using a dual-band multiport waveguide-based feeder array and a wideband lens beamformer is proposed. The parallel-plate waveguide (PPW) geodesic lens with precisely designed focal position is used to support the beamforming at sub-6-GHz (4.5–5.0 GHz) and mmW (26–30 GHz) bands simultaneously and 2) a method for the independent feeding paths of two frequency bands is developed, wherein the electromagnetic bandgap (EBG) structures with a passband in the sub-6-GHz and a stopband in mmW are implemented. In the experimental verification, 11 mmW waveguides and five sub-6-GHz waveguides are placed at the edge of the lens to obtain ±60° and ±50° beam scanning, respectively, with the corresponding scan loss of 0.2 and 0.6 dB. In addition, the sidelobe levels are below −15 and −9.6 dB with the maximum gain of 25.2 and 14.1 dBi at the mmW band and sub-6-GHz band, respectively. This work provides a dielectric-free multibeam antenna solution for multiband aperture-shared applications such as 5G communication.