Indium Tin Oxide based Optically Transparent Wide Band Flexible Circuit Analog Absorber for Optical Window Applications

In this paper, a thin, flexible, optically transparent two-layer polarization-insensitive angularly stable broad band circuit analog absorber with octagonal patches of Indium-tin-oxide resistive film patterns on a transparent Polymethyl methacrylate substrate backed by a conducting Indium-tin-oxide ground plane is designed. The structure offers -10 dB reflection bandwidth from 5.52 to 24.26 GHz frequency range, while promising absorption greater than 99% from 7 to 22 GHz with a thickness of 6.5 mm. Absorber is incidence angularly stable for the incidence angles up to 60° for both TE and TM modes. Bending analysis ensures that the proposed absorber can be used for the curved surfaces and the visual transparency makes the structure suitable for see through windows. The design guarantees a fully transparent, low profile, light weight, polarization insensitive angularly stable broadband absorber.