# _Photonics_
## 3 Results and Discussion
For 26 GHz, the surface currents along the top layer are parallel-running compared to the ones of the bottom layer, indicating that the resonance is electric in nature, as shown in Figure 5c.M. Notably, the magnetic field in the metasurface substrate is enhanced by the top and bottom currents. As a result, the surface impedance rises, and the high-impedance surface condition is achieved. Phase reflection is caused by a current impedance mismatch in the y-direction, altering the x-directional flow of the current. Ultimately, the cross-polarization is attained, allowing a y-polarized wave to be converted to an x-polarized wave and an x-polarized wave to a y-polarized wave. The anisotropic structures in the reflection mode can readily convert polarization, although they are sensitive to oblique incidence angles. It is possible to predict the stability and performance of a polarization conversion metasurface by analyzing its effectiveness over the span of a wide range of incidence angles. To evaluate the performance of the proposed metasurface polarization conversion, the simulation is performed with a wide variety of incidence angles from 0\({}^{\circ}\) to 40\({}^{\circ}\). The incidence obliquity shows an effect on the polarization convertor's performance regarded in terms of the PCR frequency dependence, as shown above in Figure 6. On the other hand, the normal incidence excitation used in the PCR spectrum is discussed in Figure 2b. We notice that in Figure 6, at \(\theta=10^{\circ}\), the structure  
Figure 5: Surface current distributions of the alleged polarizer of the top and bottom metallic layers at the resonant frequencies: (**a**,**b**) 13.78 GHz; (**c**,**d**) 26 GHz. is fairly stable for the operating bandwidth. At \(\theta=20^{\circ}\), the higher frequency band slightly decreases to 25.2 GHz. However, the overall performance is fairly stable for the operational frequencies. PCR \(>\) 80% is present in the range of frequency of 12.8 GHz to 25.6 GHz. At \(\theta=30^{\circ}\) and \(40^{\circ}\), the higher frequency band slightly decreases to 24 GHz and 23.1 GHz, respectively. It is assumed that throughout a large range of incidence angles, the specified metasurfaces can perform in a broad operating band. Similarly, when the incidence angle reaches \(\theta=30^{\circ}\), it can function over the frequency range of 12.8-16.3 GHz and 16.8 GHz to 24.3 GHz with a PCR of more than 80%. The PCR findings are likewise in good agreement at \(\theta=40^{\circ}\). Notably, the initial PCR peak persists at 13.7 GHz for all the incidence angle values chosen, making the alleged polarization converter unresponsive at this frequency of operation to incidence obliquity. The proposed structure is further investigated for various periodicity values of the unit cell, namely, P = 6.2 mm, 6.5 mm, and 6.8 mm. However, the remaining parameters are kept the same. There is no significant effect on the performance of the alleged cross-polarization converter by the size increase in the unit cell. In the frequency range of 13-25 GHz, the value for PCR \(>\) 80% and approaches unity, as shown in Figure 7. Comparison of unit cell size, thickness and different parameters of our work with recently published papers can be seen in Table 1. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & **Unit Cell Size** & **Thickness** & **Operating** & **Polarization** & **PCR** \\  & **(mm)** & **(mm)** & **Bandwidth (GHz)** & **Conversion** & **PCR** \\ \hline
[35] & 6.4 & 1.6 & 12.4–27.96 & LP to LP & PCR \(>\) 0.9 \\ \hline
[45] & 7 & 1.6 & 13–26 & LP to LP & PCR \(>\) 0.9 \\ \hline
[46] & 14 & 0.8 & 4–14 & LP to LP & PCR \(>\) 0.93 \\ \hline
[47] & 8 & 3 & 8.6–22 & LP to LP, LP to CP & PCR \(>\) 0.9 \\ \hline
[48] & 10 & 3.5 & 3.37–22.07 & LP to LP & PCR \(>\) 0.9 \\ \hline Our work & 6.2 & 1.6 & 12.94–16.54, 17.54–26 & LP to LP & PCR \(>\) 0.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of unit cell size, thickness and different parameters of our work with recently published papers.