Design and Modeling of a Miniaturized Multilayer Metamaterial Absorber With Oblique Angle and Polarization Insensitivity

Abstract

This letter introduces a novel multilayer metamaterial absorber design suitable for multiband applications in the C, X, and Ku frequency bands. The absorber’s compact nature, wide oblique angle coverage, and insensitivity to polarization angles make it a versatile solution. This absorber is designed by stacking two dual-band metamaterial absorbers. The upper layer incorporates a design composed of four concentric rings loaded in a cross configuration. Meanwhile, the middle layer is formed with two sets of embedded rings and split rings, all centered around a crossed rod. The absorber exhibits absorption peaks above 90% in the frequency bands of operation. Importantly, its performance remains consistent across varying polarization angles and is capable of sustaining absorptivity exceeding 90% at oblique angles of up to 60° for both transverse electric (TE) and transverse magnetic (TM) modes. A comprehensive model is established to elucidate the absorption mechanism and investigate the interplay between geometric characteristics and absorptivity. This model aids in adapting the structure to specific frequency requirements. Practical fabrication is accomplished using a straightforward printed-circuit board fabrication technique. Experimental measurements closely align with the anticipated performance, validating the effectiveness of the proposed multilayer absorber design.