## 4 Result and Discussion  
The design is analyzed by considering the perfect electric conductor in the ground and patch material. Still, during the fundamental analysis of the prototype, due to the lossy behavior of the material, different performance characteristics such as the reflection coefficient and radiation pattern will provide a slightly different response compared to the ideal situation. The minor shape variation in the prototype-making affects the performance of the structure. The real-time analysis of varying performance indicates design, noise, weather conditions and many other things that will affect the performance [28]. Linearity and time-invariance are often used as assumptions to make issues more manageable. However, there were excellent reasons to grow entrenched in the LTI assumption, and it may now be too constraining for antenna engineers. Nevertheless, the LTI assumption is very useful in a few crucial areas. One advantage is that it simplifies computations and models, which has traditionally been a required step due to limited processing capability [29]. The performance analysis of the design is carried out using the scattering parameters at high frequency. The input is applied using the coaxial feed. The input from the feed energizes the patch of the structure that generates the fringing field effect, and accordingly, the antenna starts the radiation. The minimum value of the scattering parameter represents better performance. The primary purpose of the proposed design is to target the maximum number of applications using the single antenna; the multiband response helps to achieve multiple applications [30]. Few analyses are carried out to accomplish the multiband response with better performance. The first analysis is to vary the feed position from the outer corner to the center. The variation is moved in diagonally. The outermost part is 1 mm, and the maximum shift point is 20 mm. The Fermi plot response is represented in Figure 3. The Fermi plot indicated the effect of the reflection coefficient response for the diverse value of feed position. The Fermi plot means there are multi-band responses based on color variation. The red color indicates the value near zero, and the color variation from red to blue represents reducing the reflection coefficient response. It is clear from Figure 3 that the multiband response for the feed position at 1 mm. Therefore, the optimization of the reflection coefficient response for the different feed values is identified. Figure 4 represents the line plot for different feed positions. Initially, the distinct value of the feed point values varied from the outer to the inner side. There is multiband resonance observed from the different feed positions. Therefore, based upon the analysis in terms of S\({}_{11}\) and gain plot, the optimum value considered is 1 mm. The second analysis is carried out for improving the reflection coefficient by adjusting the height of the superstrate region over the patch element. The superstrate concept helps to achieve multiband response, better gain and bandwidth enhancement. It also allows for enhancing the strength of the material [31]. The effect of superstrate height above the patch area for the reflection coefficient response is represented in Figure 5. The field confinement  
Figure 3: The reflection coefficient response plot over different feed positions 1 mm to 20 mm. of the structure is also enhanced due to the concept of the superstrate. A trade-off must be performed as the gap size among the patch and superstrate region increases and the overall dimensions increase. The superstrate's height varies from 0 mm to 3 mm. The line plot of the gap variation is shown in Figure 6. The height variation makes the reflection coefficient response more confined. The optimized size of 2 mm is achieved to target the multiband response. The bands are a little bit shifted as per the gap variation. There are four split-ring resonators loaded at the top of the superstrate area.