Reflective Focusing Based on Few-Layer Gradient Metasurface Element Array

Abstract

This study proposes a three-layer focusing gradient metasurface for wavefront processing. The structure works in the frequency range of 15-25 GHz and has a central frequency of 19.6 GHz. The metasurface unit is organized in a square and has high-impedance elements that reflect the full range of phase shifts. When the microwave beam is incident on this metasurface, the high-impedance elements modulate the beam according to the gradient arrangement, to realize the focusing effect of the lens, and the efficiency reaches 82%. The simulation results are consistent with the theoretical results.

Realization and validation of continuous tunable metasurface for high resolution beam steering reflector at K‐band frequency

“…The measurements results of reflection phase calibration curves, which link the varac-tor DC reverse bias to the reflection phase at the operating frequency for several different operating frequencies, are shown in Figure 4 The phase calibration curve allows extracting the appropriate DC reverse biases for each column, which leads to the required phase difference, Δϕ, between the columns. Thus, creating the desired phase distribution on the MS reflector, for the required θ steering according to Equation (5).…”

“…MS is used in various frequencies for different electrical engineering fields 1 . For example, compact filters 2,3 and special antennas 4 in sub 6 GHz, reflecting focusing in K‐band, 5 flat parabolic surface for imaging, and beam propagation manipulation in W‐band 6 . MS perfect absorber was designed to detect micro‐poisons in drinking water in millimeter‐wave 7 .…”

Multi-channel terahertz focused beam generator based on shared-aperture metasurface

“…As a simple and effective method to control electromagnetic waves, coding metasurfaces have attracted extensive attention in recent years. [1][2][3][4] By pre-arranging coding elements with different amplitudes and phases based on periodic or aperiodic laws, coding metasurfaces achieve radar cross section (RCS) noise reduction, [5,6] focusing, [7,8] beam splitting, [9,10] vortex, [11,12] etc. For example, in 2020, Han et al designed a metasurface composed of an inner rectangular ring and an outer Jerusalem cross structure combining "C" shaped branch to realize the RCS reduction function.…”

High Efficiency Focusing and Vortex Generator Based on Polarization-Insensitive Gallium Nitride Metasurface

“…At the same time, traditional lenses are not suitable for some flat optical devices because of their convex structure. Therefore, it is particularly important to design lenses with a small volume and high efficiency [5][6][7][8]. In comparison to natural materials, metamaterial, as a kind of artificially designed composite material, has supernormal physical properties such as negative refraction and electromagnetic stealth, which natural materials do not have [9][10][11].…”