## 3 Results and Analysis
### Simulation Results
The surface current distribution conditions when a voltage dip appears on the resistor is shown in Figure 5a,b for Model A when the polarization angle is 90\({}^{\circ}\) and Model B when the polarization angle is 100\({}^{\circ}\), respectively. For all models the surface current is observed to converge toward the via and subsequently diverge from it, with comparable current density on both the incoming and outgoing paths. This balance indicates that the current flows through the via without being diverted into the lumped resistor, indicating that the lumped resistor does not absorb any current. This occurs when the incident electric field is oriented perpendicular to the direction of the lumped resistor position from the center of the patch, such that it does not induce a potential difference between the patch and the ground. Consequently, no driving voltage is developed across the terminals of the lumped resistor. While the surface patch supports in-plane current flow driven by the incident electric field, these surface currents tend to converge toward the via. However, due to the geometric symmetry of the unit cell an equal amount of current diverges away from the via on the opposite side. This symmetric inflow and outflow form a balanced current pattern, resulting in minimal net current entering the resistor. As illustrated in Figure 5, the surface currents are distributed symmetrically around the via, and no power is dissipated in the resistor. Under these conditions the structure supports purely reactive surface current flow on the patch, characterized by the storage and exchange of electric and magnetic energy with negligible resistive energy absorption through the via-resistor path. Therefore, in this design the polarization-dependent behavior of the metasurface stems from the use of a single lumped resistor connected through a shifted via, which breaks the symmetry of an otherwise centrally symmetric patch structure, leading to variations in absorption depending on the polarization angle. The frequency response of the metasurface under varying conditions can be categorized into two distinct effects: shifts caused by structural differences between models and shifts caused by changes in polarization within a single model. The first type of frequency shift arises from differences in the physical structure of the metasurface unit cell, specifically  
Figure 5: Surface current distribution around the via on the back-side of the patch for the metasurface in Figure 1, when the electric field is perpendicular with the position of the lumped resistor from the center of the patch and the voltage on the resistor is minimum (dip appears): (**a**) first model at 5.114 GHz, (**b**) second model at 5.136 GHz. The left panel: front view of 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. the position of the lumped resistor. In this study, Models A and B utilize point resistors placed along different axes (the \(y\)-axis for \(\varphi_{p}\) = 0\({}^{\circ}\) and the \(x\)-axis for \(\varphi_{p}\) = 10\({}^{\circ}\), respectively). As shown in Figure 2, even under the same polarization angle these two models exhibit different resonance frequencies. This difference is attributed to variations in the effective resonance conditions caused by the different resistor positions relative to the electric field distribution on the patch. The displacement of the resistor alters the local surface current flow and modifies the electromagnetic coupling, resulting in a shift in the frequency of maximum absorption. The second type of frequency shift occurs within the same metasurface model when the polarization angle of the incident electric field is varied.