Design of Metamaterial Absorber for Large Angle Oblique Incidence with Impedance Matching

Abstract

In this paper, to realize stable absorption under large angle oblique incidence, a metamaterial absorber (MA) with air cavity embedded with lumped resistors is proposed by optimizing its input impedance to match the oblique incident interface wave impedance at transverse electric (TE) polarization mode. According to the vector transmission line equations, the characteristic impedance of transmission line for oblique incidence can be derived. As a result, the absorption band over 90% at the angle from 60° to 70° is improved to 7.9 - 12.3GHz since the impedance is well matched through adjusting the absorber's plane structure.