Multifunctional Transmissive/Reflective Rasorber With Polarization-Independent and All-Polarized Manipulations

In this letter, a novel multifunctional frequency-selective rasorber (FSR) with switchable transmissive/reflective in-band is presented. Owing to the proposed design strategy, three distinct operating mechanisms are integrated into our structure, thereby enabling a tri-state response in one system. The in-band window can be switched between transmission and shielding states, while high-efficiency absorption bands are realized at both sides of the in-band. By employing two identical and orthogonally arranged lossless coplanar layers, the polarization-independent controlled performance could be realized within the active band. A miniaturized lossy hybrid resonator, whose periodic dimensions and operating frequencies are matched to those of the lossless array, has been developed to achieve the aforementioned functionalities upon integration with the lossless one. The desired three-state functions could not only be obtained and controlled under TE and TM polarizations, but also extended to arbitrary polarizations. Finally, the effectiveness of the design is validated through the good agreement among equivalent-circuit calculations, numerical simulations, and experimental measurements.