A Rasorber-Like Waveguide Based on Thin Film

A novel rasorber-like property is generated in the new designed waveguide, which is constructed by placing an etched lossy thin film in the rectangular waveguide. Two individual transmission modes are observed in this structure in the working range of the rectangular waveguide, which provide the absorption band and passband, respectively. A sample based on indium tin oxide film is also fabricated and measured, and the results show good agreements compared with those of the 3-D full-wave simulation. This letter may extend the application of thin films in the wave propagation area, especially in the electromagnetic shielding of practical electronics.