A polarization‐insensitive broadband rasorber with in‐band transmission response

Abstract

AbstractIn this letter, a polarization‐insensitive broadband rasorber structure with in‐band transmission response has been presented. The proposed structure comprises a periodic arrangement of convoluted cross‐dipole pattern in the top layer and square slot geometry in the bottom layer. Lumped resistors are symmetrically mounted across the top pattern to result in wideband absorption, whereas in‐band transmission is obtained by careful design of the square slot in the bottom layer. The overall structure exhibits a broad absorption band (having reflection coefficient below −10 dB) in the range of 2.18 to 9.80 GHz, and the transmission band appears at 6 GHz with an insertion loss of 0.56 dB. The novelty of the proposed design lies in its compact topology, polarization‐insensitivity, angular stability, and in‐band transmission response unlike the existing rasorber structures. Surface current distribution, equivalent circuit model, and several parametric variations have also been illustrated for in‐depth analysis. A sample prototype has been fabricated and the measured results show a good agreement with the simulated responses, under normal as well as oblique incidence.