A Dual Band Metamaterial Inspired Absorber For WLAN/Wi-MAX Applications Using A Novel IShaped Unit Cell Structure

This article presents a dual band metamaterial absorber suitable for applications over the WLAN and Wi-MAX frequencies on a metal-backed FR-4 Epoxy substrate utilizing a novel I-shaped unit cell structure for the design. The component shows dual band absorption at frequencies 3.5 GHz and 5.8 GHz respectively with 100% absorption of the incident signal at both the points of observation. The component is developed on a substrate of thickness 1.5 mm that corresponds to a dimension of lambda/34 ( nearly) for the frequency of 5.8 GHz - that highlights the miniaturized design performance of the structure. The novel Ishaped unit cell structure that consists of two C-shaped oppositely faced rectangular strips with a thin I-shaped patch in between, shows exquisite metamaterial-like performance when examined. A good match of frequency band can be achieved between the performances of the simulations and the experiments. Surface current distributions are investigated to conclude about the reasons for which the structure is acting like a metamaterial absorber and its performances under different incident angles of the incoming signal were studied.