Novel Wideband Perfect Reflector with Linear-Cross Polarization Conversion Ability for X/Ku/Ka-Band Applications Including Bandwidth Adjustment

This article proposes a novel wideband reflective type metasurface that performs linear-cross polarization conversion and perfect reflector operation in different bands. The polarizer unitcell primarily consists of a top Frequency Selective Surface (FSS) printed on the low-loss grounded substrate. It shows the minimum 90% Polarization Conversion Ratio (PCR) from 9.66- 14.72 GHz and almost zero PCR from 15–22 GHz for the linearly polarized Electromagnetic (EM) wave incidence. In addition to the linear-cross, the design also demonstrates the linear-circular conversion with a 3 dB Axial Ratio (AR) from 8.27 to 9 GHz (X-band) and 14.90 to 15.07 GHz (Ku-band). The performance is stable up to 45° for oblique incidences in the elevation plane. Multiple surface plasmonic resonances are the reason for the dual operation, and the near electric field patterns agree with the presented response. The operational bands are tunable mechanically by adjusting open-ended stub dimensions connected to the unitcell's inner loop. The design has volumetric architecture of 1.709(λ
L
³
/1000), λ
L
is the free-space wavelength of the lowest operational frequency. Due to the angular stable linear-cross polarizers and perfect reflectors at different frequency bands in a single design would be useful in real-time applications where dual-operation is the primary concern.