Based on 2.5-D Large Angular Oblique Incidence and Polarization Insensitive Absorber Design

Abstract

This paper proposes a via-based novel metamaterial absorber (MA) for achieving stable energy absorption at/under oblique incidence of large angle. The TMV s of the absorber are located in the center of the patches to connect the two metal patches from different sides to achieve the miniaturization effect. This method reduces the center frequency of MA by introducing a vertical TMV s to play an important role in angle stability and polarization insensitivity. A set of closed-form equations were applied to effectively calculate the circuit inductances and capacitances, and the changes caused by the addition of vias can be seen more visually. Meanwhile, according to the vector transmission line equations, the impedance characteristics of transmission line at large angular oblique incidence can be obtained, and the design of the absorber can be simplified by matching the impedance with that of the free space. Finally, a MA with angle stability and polarization insensitivity characteristic is designed. The simulation results show that when the oblique incident angle is in the range of 60 to 70 degrees, the bandwidth is 2GHz (from 11.98GHz to 13.11GHz) with a high absorptivity (≥ 90%) for both TE- and TM- mode.