A Rasorber with a Selective in-Band Transmission Response between Wide Absorption Bands

Abstract

A polarization-insensitive frequency selective rasorber structure with a highly selective transmission band is presented in this paper. The unit cell of the proposed design comprises a top lossy layer and a bottom lossless layer resulting in broadband absorption and narrow-band transmission responses, respectively. The novelty of the topology lie in its selective in-band transmission response at 9.3 GHz (with a 3-dB bandwidth of 13%) appearing between two wide absorption bands, spreading between 3.6 to 8.10 GHz and 10.50 to 13.30 GHz (having above 80% absorptivity). The structure has several other advantages, such as low footprint, angular stability, and wide adaptability. An equivalent circuit model and several parametric variations are also carried out to explain the operating principle of the geometry. Finally, a sample prototype has been fabricated and experimentally demonstrated for validation.