Flexible and Transparent W-Band Absorber Fabricated by EHD Printing Technology

A mechanically flexible and optically transparent millimeter-wave broadband absorber was proposed and fabricated. The absorber showed >90% absorption in (73.5-110) GHz, covering the whole W-band. The key frequency selective surface used a concise metal mesh structure fabricated by the electrohydrodynamics (EHD) printing technology, which formed a classic sandwich structure together with a transparent dielectric layer and a transparent and conductive backplane. The transmittance of the sample in the visible light region was 58.1%. To testify the flexibility, the absorber was conformed to cylinders with a radius of 34 and 16 mm, respectively. The measured normalized S 11 increased with bending. Simulation results also showed that the absorption over W-band was >80% within (0°-45°) incident angle and was insensitive to the polarization angle.