Multiple Wideband Reflective Polarizer With Simultaneous Linear-Circular and Linear-Linear Conversion Ability for X to Ka-band Applications

A novel linear-circular and linear-cross reflecting types wideband polarization converter applicable for the X-Ka band frequency range is suggested in this article. A resonant electric dipole is printed on the grounded low-loss dielectric substrate and a circular patch that makes up the top metallic resonator in the polarizer’s unitcell. From 10.31-11.54 GHz, $\mathbf{1 2. 0 4 - 2 9. 5 6 G H z}, 33.26-40.69 \mathrm{GHz}$, and $41.75-43.78 \mathrm{GHz}$, the proposed converter executes linear-circular conversion with an effective $\mathbf{3 d B}$ axial ratio of $\mathbf{8 5. 3 3 \%}, \mathbf{2 0. 0 9 \%}$, and $\mathbf{4. 7 5 \%}$ fractional bandwidth, respectively. Furthermore, this design is capable of linear-cross conversion in three distinct frequency ranges: 11.56-12.03 GHz, 29.96-33.26 GHz, and $40.06-41.74 \mathrm{GHz}$, all with a $\mathbf{9 0 \%}$ polarization conversion ratio. Surface current distributions, which reveal the plasmonic resonances that generate the multiple conversions, are investigated to study the polarization conversion mechanism. The design’s performance is evaluated at various oblique angles under the Transverse Electric and Magnetic modes. With a total thickness of $0.041 \lambda_{L}$ and dimensions of 0.206 $\lambda_{L} \times 0.206 \lambda_{L}$, the proposed polarizer is modest in electrical terms. Here, $\lambda_{L}$ is the free-space wavelength at the lowest operational frequency. The proposed unitcell is ideal for real-time applications due to its distinctive compactness and polarization conversions; here is where the concept’s novelty resides.