Millimeter Wave Beam Steering Reflectarray Antenna Based on Mechanical Rotation of Array

Muhammad Inam Abbasi,Noor Hafizah Sulaiman,Muhammad Hashim Dahri,Norhudah Seman,Mohd Haizal Jamaluddin,Muhammad Ramlee Kamarudin

doi:10.1109/access.2019.2945318

Abstract

This work provides design and analysis of a beam steering reflectarray antenna, designed at 26 GHz, based on the mechanical rotation of the array. Unit cells based on circular ring elements are designed, and scattering parameter measurements have been carried out for obtaining progressive phase distribution. The unit cell measurements demonstrated a maximum reflection loss of 4 dB with a total phase range of almost 360°. Symmetricity of the array and the resonant elements has been exposed to steer the main beam by tilting the reflectarray at different angles. A beam steering range of more than ±60° has been demonstrated by varying the tilt angle from +30°to -30°. The designed 20 × 20 element array provided a maximum gain of 26.47 dB at 0° which reduced to 19.8 dB at 61.9° in the elevation plane. On the other hand, the reflectarray antenna demonstrated a maximum bandwidth of 13.1% with a minimum side lobe level of -25.9 dB.

Highlights

The advantageous nature of reflectarray antennas in many aspects over parabolic reflectors and phased arrays have made it suitable in advanced high gain antenna applications including 5G communication systems
Controlling the phase of individual elements by using RF MEMS [5], [6], using PIN diodes as switches [7] and employing varactor diodes to vary the capacitance of the resonant elements [8], [9] are some of the most commonly demonstrated techniques for electronic beam steering
In order to highlight the focus of the beam, threedimensional measured radiation pattern results are shown in Fig. 8 where main beams can be seen at different positions in UV plane for different tilt angles

Summary

INTRODUCTION

The advantageous nature of reflectarray antennas in many aspects over parabolic reflectors and phased arrays have made it suitable in advanced high gain antenna applications including 5G communication systems. In order to rectify the losses associated with electronic beam scanning techniques, mechanical control of individual reflectarray elements using micro motors and actuators has been proposed in [12]–[19]. In these techniques, micro motors are connected to the resonant elements which are continuously rotated up to 180◦, providing a phase shift range of 360◦ without any quantization loss. Micro motors are connected to the resonant elements which are continuously rotated up to 180◦, providing a phase shift range of 360◦ without any quantization loss These motors are usually attached at the backside of reflectarray without having any effect on element radiation.

REFLECTARRAY ELEMENT DESIGN AND MEASUREMENTS

BEAM STEERING REFLECTARRAY

Findings

CONCLUSION