Review of Recent Phased Arrays for Millimeter-Wave Wireless Communication

Abstract

Owing to the rapid growth in wireless data traffic, millimeter-wave (mm-wave) communications have shown tremendous promise and are considered an attractive technique in fifth-generation (5G) wireless communication systems. However, to design robust communication systems, it is important to understand the channel dynamics with respect to space and time at these frequencies. Millimeter-wave signals are highly susceptible to blocking, and they have communication limitations owing to their poor signal attenuation compared with microwave signals. Therefore, by employing highly directional antennas, co-channel interference to or from other systems can be alleviated using line-of-sight (LOS) propagation. Because of the ability to shape, switch, or scan the propagating beam, phased arrays play an important role in advanced wireless communication systems. Beam-switching, beam-scanning, and multibeam arrays can be realized at mm-wave frequencies using analog or digital system architectures. This review article presents state-of-the-art phased arrays for mm-wave mobile terminals (MSs) and base stations (BSs), with an emphasis on beamforming arrays. We also discuss challenges and strategies used to address unfavorable path loss and blockage issues related to mm-wave applications, which sets future directions.

A Tiled C-Band Dual-Polarized 1-Bit Transmitarray

“…Due to the lengthening of the induced surface current path, a square-ring microstrip antenna has a smaller size compared to a patch antenna for the same resonant frequency, [9]. The proximity coupled (electromagnetic) feeds are employed using the open-ended half-wavelength semi-annular (U-shaped) microstrip loops in the layer beneath the ring antennas, which allows enhanced bandwidth when the feed and ring are properly aligned, [1]. The microstrip width of the square ring and feeding loops were optimized for the maximum return-loss bandwidth.…”

“…High gain, high-efficiency and wideband antennas constitute the core enabling technology of the emerging millimetre-wave 5G wireless communications and surveillance systems, [1]- [2]. The beam-steering and beamforming are also regarded as the essential functionalities of the 5G antennas.…”

2 Bit Reconfigurable Unit-Cell and Electronically Steerable Transmitarray at $Ka$ -Band

“…For the future 5 th Generation mobile terrestrial networks, several frequency ranges GHz, or 37.0 -40.5 GHz) at Ka-band have been indicated as potential candidates for the development of high performance backhauling and access point systems [8]. In the last years, several phased array solutions [9] have been proposed and are generally based on analogue [10] or fully-digital architectures [11].…”

A Tunable Beamforming Ferroelectric Lens for Millimeter Wavelength Ranges

“…Such devices should become a base for innovative infrastructures such as the 5G network [1], WiGig network [2], "smart home", and its probable extension to the "smart city" [3]. To overcome these challenges, one looks for a further increase of the operating frequency and migration to the millimeter wavelengths range [4]. However, the millimeter wavelength range demonstrates a significant attenuation of electromagnetic waves in free space [5]; thus, the antennas with high directivity are of interest.…”