Design and investigation of indium tin oxide-based transparent broadband microwave absorbers

Abstract This paper presents the design of a novel wideband transparent microwave absorber based on indium tin oxide (ITO). The absorber adopts a multilayer structure, with the top layer composed of a nested square structure made of ITO material, an intermediate dielectric layer of polyvinyl chloride (PVC), and a bottom layer of polyethylene terephthalate (PET) coated with ITO as the reflector. By optimizing structural parameters such as the thickness of the ITO film and the dimensions of the spacer layer, efficient broadband microwave absorption exceeding 90% is achieved within the frequency range of 2.43 to 5.67 GHz, while simultaneously meeting requirements for optical transparency and broadband performance. Simulation experiments and theoretical analyses demonstrate excellent polarization and incident angle stability of the absorber structure. Finally, samples are fabricated using screen printing technology, and free-space testing results are consistent with simulation predictions, validating the feasibility of the design.