Wide angle metamaterial absorber for S, C and X band application

Abstract

Abstract In this article, an angle independent Metamaterial Microwave Absorbers (MMA) is designed and demonstrated. The design consists of two concentric hexagon connected through consolidated resistors. The absorber is imprinted on a metal-backed low cost FR4 dielectric substrate with a thickness of 3.2 mm (λ/0.07) and a dielectric constant of 4.3. The proposed structure exhibits a wide absorption bandwidth ranging from 2.8 to 10.42 GHz with absorptivity above 90 % covering S, C and X Band. In the area of interest, the current and electric field distribution has been examined, for two maximum peaks at a frequency of 3.66 and 9.54 GHz, with maximum absorptivity of 99.99 % and 99.44 % respectively. The presented absorber is examined under different polarization angles for phi and theta variation. The fabricated sheet consists of an array of a unit cell, which is examined inside the anechoic chamber with the help of two horn antennas and VNA. The tested and simulated results are compared and it was found that they are almost similar to each other with little variation due to fabrication tolerance. The presented absorber can be practically used for defence applications for Radar Cross Sections (RCS) reduction.