## 4 Results and Discussion  
Updated microwave simulator CST software was activated to simulate the whole spectrum. Absorption, reflection, and transmission spectra for the suggested perfect metamaterial absorber (PMA) are depicted in Figure 2. At normal incidence, the simulation results show higher absorbance at all dual resonance frequencies which are 99.15% and 99.76% at 6.45 GHz and 14.89 GHz respectively that remains within the C and Ku bands with remarkable bandwidth. The transmission coefficient is zero for all resonance frequencies because of keeping the completely metallic thin shift at the bottom of the unit which is equal to the dimension of the substrate. The following equation is used to calculate the average absorption efficiency of the projected metamaterial:  
\[A_{\text{avg}}=\frac{1}{\lambda\mathcal{U}-\lambda L}\int_{\lambda L}^{ \lambda\mathcal{U}}A\;(\lambda)d\lambda \tag{5}\]  
here, \(A(\lambda)\) is the wavelength response of the absorption coefficient. Polarization insensitivity and independency of the oblique incidence angle are the important tasks of the perfect metamaterial absorber design. Both of these properties play the vital role of overcoming the typical drawback of an MA with a single polarization and a small working angle. An ideal absorber is one that operates the polarization angle independently as well as having a wide working angle, and is capable of absorbing approximately unity of the projected EM radiation that happen at normal angles. The simulated result of the amplitude of absorption of the proposed PMA for TE polarization incident waves is shown in Figure 3. At 0\({}^{\circ}\), the absorption at the dual resonance frequencies 6.45 GHz and 14.89 GHz is 99.15% and 99.76%, respectively. If the polarization angle changes to 30\({}^{\circ}\), the resonance frequencies change slightly to a higher frequency. The two resonance frequencies were changed to 6.816 GHz and 16.128 GHz with 94.5% and 98.36% absorption, respectively. Then the polarization angle changes to 60\({}^{\circ}\). Therefore, the corresponding resonances are observed at 6 GHz, 11.87 GHz, and 13.5 GHz with 47.9%, 97.17%, and 89.5% absorption, respectively. For 90\({}^{\circ}\), the resonance frequencies are 11.9 GHz, and 13.5 GHz with 73%, and 71.5% absorption, respectively. It is mentioned that the proposed absorber shows the polarization angle unaffected up to 30\({}^{\circ}\) and showing polarization sensitivity up to 90\({}^{\circ}\). The amplitude of absorption for different oblique incidence angles, such as \(\theta\) = 0\({}^{\circ}\), 30\({}^{\circ}\), 60\({}^{\circ}\) and 90\({}^{\circ}\) are analyzed in Figure 4. It is seen in Figure 4 that as the oblique incidence angle increases, the absorption frequency of the absorber changes slightly to a lower frequency with high absorptivity. However, as the angle of oblique incidence changes, the absorption will of course decrease as the capability of the MMs\({}^{\prime}\) structure to conduct the flowing current in the dielectric between the two metal layers is reduced. Therefore, the proposed absorber is wide, with an oblique incidence angle up to 60\({}^{\circ}\). Effective permittivity and permeability are two important factors to explain the properties of metamaterials. These parameters can also be obtained using the scattering parameter. The effective permittivity and permeability are shown in Figure 5a,b. As can be seen from this figure, both effective permittivity and permeability have negative values around the resonance frequency (\(\epsilon_{\text{eff}}\) < 0 and \(\mu_{\text{eff}}\) < 0). The absorption technique of the offered MA could be well explained by investigating the electric field distribution, magnetic field distribution and surface current density. These three phenomena are depicted in Figures 6-8 at the two resonance frequencies 6.45 GHz and 14.89 GHz, respectively.