A Thin Multilayer Broadband Metamaterial Absorber based on ITO

We proposed a thin multilayer broadband metamtaterial absorber based on Indium-tin-oxide (ITO) resistive film, which is used to broaden the bandwidth. The element of absorber consists of three layers. In each layer there is a FR-4 substrate and an ITO attached to polyethylene terephthalate (PET) film. The mechanism is analyzed and discussed in depth in terms of the equivalent circuit and the electric field distributions. Although the proposed absorber features multilayer, the total thickness is only 3.5 mm, i.e., 0.079 λ L at the lowest operating frequency. The −10 dB operation bandwidth (RL<-10 dB) ranges from 6.8 GHz to 20.8 GHz, exhibiting a fractional bandwidth of 101.4%. In addition, the absorption of the proposed absorber is more than 80% under 50°of incident angle for both transverse electric and transverse magnetic polarizations.