CPW-fed all-metallic vivaldi antennas with pattern diversity for millimeter wave 5G access points

Abstract

A coplanar waveguide (CPW) fed uniplanar all-metallic antenna is proposed for mmWave 5G access points. The antenna has an impedance bandwidth from 26 to 30 GHz with a corresponding end-fire gain of 8 dBi at 28 GHz. The effective radiating volume is 0.0031λ30 indicating a high gain yield for minimal physical footprint. The radiation efficiency is 99.5%, and the losses are primarily due to finite conductivity of copper. The pattern integrity is high across the band with cross-polarization level below 30 dB, due to lack of electrically thick dielectric substrate. Industry standard low-cost chemical etching technique is used for fabrication of the prototype. A compact, co-polarized stacked beam switching module is also proposed for wide angular coverage with three-ports. This module houses the proposed all-metallic antennas for beam switchability. A customized 3D-printed scaffolding using polylactic acid (PLA) is designed to house the proposed antennas. The antenna module has a wide angular coverage of ±50◦ . Since the proposed antenna has high radiation efficiency with high gain for minimal physical footprint, it could be a potential solution for mmWave 5G access points. Detailed simulated and measured results are presented with technical justification.