Research Article E-Band Beam-Steerable and Scalable Phased Antenna Array for 5G Access Point Md. Mazidul Islam , 1 Mikko Leino, 2 Rasmus Luomaniemi, 2 Jinsong Song, 3 Risto Valkonen, 4 Juha Ala-Laurinaho , 2 and Ville Viikari 2 1 Keysight Technologies Finland Oy, Elektroniikkatie 10, 90590 Oulu, Finland 2 Department of Electronics and Nanoengineering, Aalto University, Aalto FI-00076, Finland 3 Smart Antenna Technologies Ltd., Birmingham Research Park, Birmingham B15 2SQ, UK 4 Nokia Bell Labs, Nokia, Espoo 00045, Finland Correspondence should be addressed to Md. Mazidul Islam; md-mazidul.islam@keysight.com Received 9 April 2018; Revised 29 August 2018; Accepted 17 September 2018; Published 28 November 2018 Academic Editor: Chien-Jen Wang Copyright © 2018 Md. Mazidul Islam et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper presents a new implementation of the beam-steerable two-dimensional phased antenna array for the forthcoming 5G networks. The antenna enables easy integration of phase shifters and other active electronics on a single PCB, low-loss feed network, low profile, and beam steering in both azimuth and elevation plane. In addition, the antenna is scalable in the number of elements and it can be made compatible with low-cost mass production in plastic injection molding with a metal coating. The antenna consists of a rectangular waveguide feed network, waveguide-to-PCB transitions, phase shifters on a PCB, and horn antenna radiating elements. The parts have been first designed and simulated individually and the operation of the whole structure is then verified by electromagnetic simulations. The phase shifter used in this work is a meandered microstrip line section, but the structure also enables the implementation of active phase shifters. A four-by-four antenna array prototype was manufactured. The beam-steering properties of the phased antenna array have been tested with radiation pattern measurements at 72.5 GHz, and the measured gains are compared with the simulated ones. The measured gains are 15.2 and 11.2 dBi for the boresight beam, and the beam was steered to 40 ° . 1. Introduction Millimeter-wave link frequencies such as 28, 38, and 60 GHz, as well as the E-band (71–76 and 81–86 GHz), have been proposed for use in wireless backhaul infrastructure to enable 5G networks [1–6]. Especially, the E-band provides a huge spectral resource compared to traditional microwave bands (6–42 GHz) and bandwidths comparable to 10–100 Gb/s fiber connections with low latency. Electrical beam steering in two dimensions, that is, in azimuth and in elevation is required to ease the antenna installation and to cope with the 5G small cell deployment sites during the operation [7]. Additionally, antennas need to be small and have a low profile for imperceptible installa- tions. High-gain antennas are needed together with a possi- bility to easily accommodate active components, such as phase shifters and amplifiers, to overcome propagation losses at mm-wave frequencies, increase coverage area, and improve system performance. The solution is ideally scalable in the number of elements for different antenna gains. There are many approaches proposed for implement- ing electrical beam-steering antennas, including beam switching/beam selection networks, reconfigurable high- impedance surfaces (HIS), and phase shifting or time- delay networks. An integrated lens antenna (ILA) provides good beam-steering characteristics both in the azimuth and elevation planes [7, 8]. For each beam, there is a cor- responding separate element in the focal feed array. For this purpose, a complex switching network is needed. Each switch has a considerable attenuation at mm-waves from 2 to 3 dB resulting in high overall attenuation of the switch- ing network. Another7 drawback is that the lens is bulky. Hindawi International Journal of Antennas and Propagation Volume 2018, Article ID 4267053, 10 pages https://doi.org/10.1155/2018/4267053