## 4 Result and Discussion
The superstrate approach helps to improve the performance of the structure. The width of SRR change over the 1 mm to 4 mm range is observed in Figure 7. The width variation leads toward minimizing the reflection coefficient response. Overall variation in the dimension of the SRR is not majorly affected by the reflection coefficient response. The optimized reflection coefficient response is achieved for the SRR thickness of 1 mm. The size variation of the metamaterial rings will affect the charge distribution concentration, which results in a variation in the structure's performance. The dimensions of the rings should be proper to avoid minimum variation in the simulated and measured response. The fourth analysis in the proposed design is taken by changing the number of rings to check the reflection coefficients. The optimum value of all the parametric studies is considered for the analysis, as shown in Figure 8. The graph shows that the variation of different parameters will affect the reflection coefficients. The shifting of bands with the variation in the reflection coefficients is observed. Figure 4: The line plot of S\({}_{11}\) for different feed positions. The 1 mm is considered an optimum feed position. Figure 5: Superstrate height variation over the 0 mm to 3 mm for analysis of reflection coefficient response. a peak bandwidth of 400 MHz over 10.671 GHz to 11.071 GHz. Out of all the configurations, the minimum reflection coefficient of \(-49\) dB is achieved in the four-ring designs. Figure 9: Reflection coefficient analysis for different metamaterial rings. (**a**) Minimum S\({}_{11}\) of \(-25.83\) dB and peak BW of 400 MHz attained for one ring structure. (**b**) Minimum S\({}_{11}\) of \(-23.25\) dB and peak BW of 406 MHz achieved for one ring structure. (**c**) Minimum S\({}_{11}\) of \(-24.46\) dB and peak BW of 410 MHz attained for one ring structure. (**d**) Minimum S\({}_{11}\) of \(-49\) dB and peak BW of 400 MHz achieved for one ring structure. The proposed design is numerically simulated and fabricated using the FR4 material. The reflection coefficient of the proposed optimized design is observed in Figure 10. The comparison between the measured and the simulated responses is kept. The similarity among both results is observed. The reflection coefficient response is analyzed from 4 GHz to 14 GHz. The effects are simulated with a step size of 0.1 GHz. There are six bands observed with the S\({}_{11}\) value less than \(-10\) dB. The first band was observed over the 4.611 to 4.921 GHz frequency with the S\({}_{11}\) of \(-11.38\) dB. The second band was observed over 5.071 to 5.561 GHz, with a reflection coefficient response of \(-24.08\) dB. The third band represents a reflection coefficient response of \(-18.84\) dB over the range from 7.531 to 7.881 GHz. The fourth band was observed over the 8.671 to 9.041 GHz, with the reflection coefficient response of \(-30.43\) dB. The fifth band represents a reflection coefficient response of \(-14.72\) dB over the 9.951 to 10.381 GHz. The last band was observed over the frequency span of 10.671 to 11.071 GHz, providing a reflection coefficient response of \(-49\) dB. The peak value of the reflection coefficient response of \(-49\) dB was observed in the sixth band. The proposed design provides a narrow-band response for the different resonating frequencies. The narrow-band optical receiver operating for 5.2 GHz is suitable for radio-over-fiber communication applications [32]. The endless phase shifters (EPS) operating at 7.7 GHz are utilized in space diversity combining networks of digital microwave communication systems [33]. The application for aeronautical mobile communications operates at 8.8 GHz [34]. The resonance at 10.8 GHz is used in autonomous cars and communication systems for vehicle networking [35]. The performance of different structures in summary form is represented in Figure 5.0 The four influential bands with a reflection coefficient response of less than \(-15\) dB are considered.