## 3 Results and Analysis
### Simulation Results
This misalignment prevents energy from being transferred into the resistive load, leading to negligible power absorption under this condition. To provide more physical insight into the unit cell of the proposed metasurface, an analysis of the surface current distribution is presented in Figures 4 and 5. In Figure 4, this analysis is conducted at the frequency where power absorption is at its maximum as the polarization angle is varied. The condition of the surface current distribution on the back-side of the unit cell when the electric field is aligned with the position of the lumped resistor from the center of the patch and the voltage on the lumped resistor is at its maximum is shown in Figure 4a,b for Model A at 5.114 GHz (\(\varphi=0^{\circ}\)) and Model B at  
Figure 3: The voltage on the unit cell of the first case in Figure 1 for normal incidence with different polarization angles: (**a**) Model A and (**b**) Model B. 5.136 GHz (\(\varphi=10^{\circ}\)), respectively. For all models, the current always passes through the circle in the middle (via) with different intensity between the incoming and outgoing sides. The current flow is observed to converge into the via from one side with higher surface current density and to diverge from the other side with lower density, as shown in Figure 4. This imbalance in current density suggests that a portion of the induced surface current is diverted through the via and dissipated by the lumped resistor. This condition occurs when the incident electric field has a component aligned with the direction of the lumped resistor position from the center of the patch, thereby inducing an effective voltage along that direction on the patch. The via, which is shifted from the center of the patch, breaks the geometric symmetry of the unit cell. This asymmetry results in an unbalanced surface current distribution, which enhances the coupling between the incident electric field and the resistive load. As a result a voltage difference between the patch and the ground is developed, enabling current flow through the via which is subsequently absorbed by the lumped resistor. In this configuration the surface patch still supports in-plane current flow, but a portion of the induced surface current is now directed downward through the via into the lumped resistor. This asymmetry allows a net current to enter the resistor. This leads to resistive energy absorption as the induced current flows toward the lumped resistor. Under this condition the metasurface unit cell effectively harvests electromagnetic energy, with clear voltage peaks observable in simulation. Although Figure 4a,b show strong current coupling due to the alignment between the electric field and the resistor position from the center of the patch, the current distribution patterns are slightly different. In Figure 4a, where \(\varphi_{\text{p}}=0^{\circ}\) and the polarization angle \(\varphi=0^{\circ}\), the current is concentrated along the vertical axis (y-direction). In contrast, in Figure 4b, where \(\varphi_{\text{p}}=10^{\circ}\) and \(\varphi=10^{\circ}\), the alignment results in a skew in the current flow concentration. This difference illustrates how variations in the geometric resistor position (\(\varphi_{\text{p}}\)) influence the orientation of the surface current. Figure 4: Surface current distribution around the via, viewed from the back-side of the patch of the unit cell for the metasurface in Figure 1, when the electric field is aligned with the position of the lumped resistor from the center of the patch and the voltage across the resistor is at its maximum: (**a**) first model at 5.114 GHz, and (**b**) second model at 5.136 GHz. The left panel: front view of the unit cell with the area inside the box as the focus of the surface current distribution display. The middle panels: surface current distribution contour on the back-side of the patch. The right panels: surface current distribution arrows on the back-side of the patch.