Design of Distributed and Robust Millimeter- Wave Antennas for 5G Communication Terminals

This paper introduces a practical design of distributed and simple millimeter-wave phased arrays for 5G mobile handset. Three types of antenna arrays and four different arrangements are investigated in perspective of coverage efficiency and coverage map. According to the analysis, a distributed design, including four 1 × 2 quasi-Yagi arrays along each edge of the chassis and one 2 × 2 planar patch array along the longer edge of the chassis, is adopted, considering both the antenna performance and the complexity of the feeding networks. The gain of the handset antenna system is always above 2 dBi for all the incident angles. The coverage efficiency reaches 50% for a gain of above 7 dBi, with the relatively low-gain area mainly towards the backward direction. Feeding networks are designed to verify the beam shaping ability of the arrays. The prototype was fabricated and measured. All the arrays can cover the frequency band from 27.85 GHz to 28.62 GHz, with an isolation of above 35 dB. The maximum measured realized gain is 12.1 dBi and 12.6 dBi for the Yagi and the patch arrays, agreeing well with the simulated results. High gain, large coverage efficiency, robust performance and simple feeding networks make the proposed design a good candidate for 5G mobile handsets.