Broadband Transparent Absorber Based on Indium Tin Oxide-Polyethylene Terephthalate Film

In this paper, a broadband transparent microwave absorber with a fractional bandwidth of 118.1% was designed. In the proposed absorber, a gear-shaped unit cell consisting of optically transparent indium tin oxide-polyethylene terephthalate films fabricated on a polymethyl methacrylate is developed to guarantee electromagnetic wave to well enter into and is dissipated in the absorbing structure. Two resonant frequencies at 4.8 GHz and 13.6 GHz, which correspond to electromagnetic and electric resonances, respectively, are generated to achieve a wide absorbing band from 3.86 GHz to 15.04 GHz covering S, C, X and Ku bands. The proposed absorber has the advantages of low profile, polarization insensitivity, and angular stability. The prototype of the absorber has been fabricated and measured, and the experimental results are in good agreement with the simulation results.