Wideband 3-D-Printed Metal-Only Reflectarray for Controlling Orthogonal Linear Polarizations

Abstract

This paper presents a metal-only reflectarray that enables the control of incident orthogonal polarizations in a large bandwidth. The proposed reflectarray is based on a unit cell whose tuning elements allow the independent control of the reflection phase value for the vertical and horizontal impinging polarizations. Due to the symmetry of the unit cell, the same performance is produced by each polarization when its reflection phase response is modified. The proposed unit cell provides a fairly linear phase response along the frequency with a phase variation in the orthogonal polarization of ±1 o . The performance under oblique incidence and the frequency limitation of the unit cell are also investigated. From this unit cell, a metal-only reflectarray that produces circular polarization from a linear polarization is designed. The reflectarray presents a simulated directivity greater than 27 dBi with an axial ratio below 1.5 dB from 32 GHz to 50 GHz (43.9% of bandwidth). A prototype is fabricated and the measured results agree well with the simulated ones. The obtained aperture efficiency is between 56% and 41% in the considered frequency band. The measured realized gain ranges from 27 dBi to 30.3 dBi where the achieved radiation efficiency is greater than 97%.

Three‐dimensional metal‐only phoenix cell and its application for reflectarrays

“…Table 5 compares the proposed MORA with state‐of‐the‐art MORAs. Globally, only 3D cells (either metallic blocks [14, 15, 20] or this work) can achieve an aperture efficiency higher than 50% while allowing dual polarisation.…”

“…The measured gain at 19.75 GHz is 30.25 dBi with an aperture efficiency of 51.17% respectively. Also, the measured 1-dB gain bandwidth is 15% (19)(20)(21)(22). A dual band metal-only reflectarray operating at 20 and 25 GHz is designed based on the second mode of the phoenix cell.…”

“…While this basic configuration has been widely studied, recent advancements in three-dimensional (3D) structures have offered increased flexibility in achieving a complete 360°phase range and enabled advanced functionalities. Several studies [14][15][16][17][18][19][20] have explored the use of metallic blocks and waveguides for precise control over the reflection phase. In the case of unit cells composed of metallic blocks, the reflection phase is solely determined by their heights, which imposes limitations on the performance of designed MORA.…”

All-Metal Tensor Metamaterials: Characterization and Design

“…This implies that µ xy = 0 in (2). The expressions provided by (8) reduce to closed-form solutions for µ xx and µ yy ,…”

Fully-metallic 3D mmWave Reflectarray with independent polarization steering control

“…Reflectarrays emerged decades ago as a promising technology [9], [10]. Since then the development of reflectarrays has experimented an impressive growing up to now [11]- [13], leading to a more generalized and modern conception called Reconfigurable Intelligent Surfaces (RISs) [14] where the own reflectarray is controlled by artificial-intelligence (AI) algorithms.…”