An optically transparent millimeter-wave absorber based on a double elliptical pattern

This study designed and fabricated a flexible and transparent microwave metasurface absorber. The absorber adopts a three-layer structure, consisting of patterned indium tin oxide–polyethylene terephthalate conductive layers on the top and bottom, with a polyvinyl chloride dielectric layer in between. Through a genetic algorithm to assist in structural design and parameter optimization, the absorber simultaneously achieves ohmic loss and electromagnetic resonance effects, ensuring efficient dissipation of incident electromagnetic waves within the absorbing structure. Experimental results demonstrate that the absorber achieves over 90% absorption in the 50–70 GHz wide frequency band, with absorption exceeding 99% in the 50.8–67.2 GHz frequency range, under normal incidence. Notably, the absorber maintains over 90% absorption efficiency within a wide incident angle range of 0°–30°. These structural and absorption characteristics endow it with excellent performance in shielding electromagnetic interference. Moreover, its transparency and flexibility make it applicable to applications such as automotive glass and radomes.