Millimeter-Wave Phased Arrays and Over-the-Air Characterization for 5G and Beyond: Overview on 5G mm-Wave Phased Arrays and OTA Characterization

Abstract

Millimeter-wave (mm-wave) technology is a viable candidate to address the growing data traffic in fifth-generation (5G) wireless communication and beyond. However, challenges related to free space propagation loss, atmospheric absorption, scattering, and non-line-of-sight propagation must be addressed to benefit from the promised bandwidth available in the mmwave regime. In this context, phased array technology is considered as vital to provide high-speed and seamless wireless solutions to the industry. A phased array can be defined as a multiple-antenna system that electronically controls the radiated electromagnetic beam. The official origin of the antenna array concept is attributed to Guglielmo Marconi. A repeated Morse code signal letter "S" from Poldhu, UK to St. John's in Canada was successfully demonstrated in December 1901, using a twoelement antenna array. In the early 1940s, Luis Walter Alvarez designed the first electronically scanning phased-array radar.Both scientists were awarded the Nobel Prize for their discovery. Thanks to their ability to shape or steer the radiated beam and the possibility to integrate such versatile solutions in the mm-wave regime, phased arrays have shown a growing interest from the industry [2]- [8]. While these systems have been considered for decades for large radar applications and communication links, their high cost limited their penetration for commercial applications. However, the development of new architectures, packaging and semiconductor technologies has drastically reduced the cost and complexity of phased arrays making them available to commercial markets for 5G wireless and satellite applications. In particular, 5G wireless communications is bringing this paradigm to the general public. This article presents an overview of the rise of mm-wave phased arrays in the industry including the principles and design considerations, with an emphasis on Over-The-Air (OTA) characterization. In Section II, the principle of operation and design considerations of phased array antennas are presented. A special attention is paid to phase-shifters developed in monolithic integrated technology required to control the phase profile of such arrays. The evolution toward wide bandwidth and wide scan array concepts is then proposed with connected arrays of slots and dipoles, tightly coupled dipole arrays, planar ultra-wideband modular arrays and continuous transverse stub arrays. In Section III, the OTA methodology to address the challenging task of phased arrays characterization is described [9]- [11]. Main issues encountered in mm-wave phased array measurements are identified. Dedicated OTA set-ups for standardized and specific antenna measurements are described including a discussion about measurement uncertainty. Thanks to its high potential for 5G applications and beyond, an abundant literature related to phased arrays is reported. In the last Section, the main mm-wave applications are briefly described and future trends discussed.

Innovations and Applications of Millimeter Wave Antennas: A Literature Review

“…To keep up with the ever-increasing data rate demands of wireless systems, bands of frequencies covering an extensive range from 800 MHz to 100 GHz have been assigned for use [6]. The demand for high-speed, seamless wireless solutions has propelled the evolution of millimeter-wave (mm-wave) antenna technology, particularly in the context of 5G and beyond [7,8]. Additionally, for more than a half-century, phased-array antenna technology has made an extensive effect that spans from radar to radio astronomy, and it is set to start a major change in the operation of mobile communications [9].…”

A design of compact wideband substrate integrated waveguide fractal koch surface slot antenna for Ka‐band applications

“…The 5G systems are focused on utilising the millimetre wave (MMW) band, such as Ka-band (28-38 GHz), for license-free applications. 1 In the MMW band, the microstrip patch antenna achieves wideband by loading short pins, which introduce extra resonance modes to improve the bandwidth (BW) 2 ; a T-shaped monopole antenna with asymmetric coplanar waveguide feed is used to achieve wide BW at Ka-band. 3 However, dielectric losses are increased at high frequencies, microstrip patches, dipoles, and monopole antennas, and efficiency is decreased.…”

“…Rigorous improvements have happened in 5G over the present technology. The 5G systems are focused on utilising the millimetre wave (MMW) band, such as Ka‐band (28–38 GHz), for license‐free applications 1 . In the MMW band, the microstrip patch antenna achieves wideband by loading short pins, which introduce extra resonance modes to improve the bandwidth (BW) 2 ; a T‐shaped monopole antenna with asymmetric coplanar waveguide feed is used to achieve wide BW at Ka‐band 3 .…”

Frequency Diverse Array Auto-Scanning Beam Characteristics and Potential Radar Applications

“…Since mechanically beamscanning reflector antenna has slow speed of beam scanning, typical solution is to adopt phased-array antenna [2]. Phasedarray is well known for its robust capability to electronically steer its beam with high effectiveness [3], [4], the beam steering of phased-arrays in an angle is fixed for all range cells [5], [6]. That is, a limitation of the phased-array antenna is that the beam steering is independent of the range parameter.…”