## 3 Result and Discussion
The reflectance response value reached is \(-10.10\) dB at a resonance frequency of \(8.64\) GHz, and the maximum bandwidth achieved for this is \(0.02\) GHz. Figure 7 represents a \(S_{11}\) plot by choosing the substrate as Rogers RT Duroid 5880. There are seven frequency bands observed in the CPIO and SWT antenna structures. The maximum value of the reflectance response achieved is \(-33.79\) dB at a resonance frequency of \(6.49\) GHz, and the maximum bandwidth achieved for this is \(0.18\) GHz. There are six frequency bands observed in the CPIO and SWOT antenna structures. The maximum value of the reflectance response achieved is \(-34.54\) dB at a resonance frequency of \(6.52\) GHz,and the maximum bandwidth achieved for this is 0.16 GHz. There are three frequency bands observed in the DCPIO and SWT antenna structures. The maximum value of the reflectance response achieved is \(-\)13.79 dB at a resonance frequency of 8.83 GHz, and the maximum bandwidth achieved for this is 0.51 GHz. One frequency band is observed in the DCPIO and SWOT antenna structures. The reflectance response value reached is \(-\)10.05 dB at a resonance frequency of 8.80 GHz, and the maximum bandwidth achieved for this is 0.07 GHz. Data are represented in Table 2. It is observed that more bands and minimum reflectance responses are better in CPIO and SWT antenna structures in both types of the substrate-based design. The Rogers RT Duroid-based antenna structure provides more bands and a better reflectance response than the FR4-based substrate design. Data are represented in Table 3.  
Figure 5: (**a**) The first design is the connected patch inner and patch outer (CPIO) and the SRR with the tooth (SWT) (**b**) Second design is the combined patch inner and patch outer (CPIO) and the SRR without a tooth (SWOT) (**c**) Third design is the disconnected patch inner and patch outer (DCPIO) and the SRR with the tooth (SWT) (**d**) Fourth design is the switch disconnected patch inner and patch outer (DCPIO) and the SRR without a tooth (SWOT). The voltage standing wave ratio (VSWR) represents how effectively the antenna power propagates through an antenna. Figure 8 (a) represents the VSWR response by choosing the substrate as FR4. The CPIO and SWT antenna structures provide a VSWR of 1.51 at 3.38 GHz. The CPIO and SWOT antenna structures provide a VSWR of 1.18 at 3.39 GHz. The DCPIO and SWT antenna structures provide a VSWR of 1.83 at 7.87 GHz. The DCPIO and SWOT antenna structures provide a VSWR of 2.21 at 8.64 GHz. It is observed that the connected interior and exterior patch (CPIO) design provides a better VSWR than the disconnected interior and exterior patch (DCIOP) design. Data are represented in Table 3. Figure 8b depicts the VSWR response by choosing the substrate as Rogers RT Duroid 580. The CPIO and SWT antenna structures provide a VSWR of 1.05 at 6.49 GHz. The CPIO and SWOT antenna structures provide a VSWR of 1.03 at 6.52 GHz. The DCPIO and SWOT antenna structures provide a VSWR of 2.33 at 8.83 GHz. The DCPIO and SWOT antenna structures provide a VSWR of 5.67 at 8.80 GHz. Data are represented in Table 2. \begin{table}
\begin{tabular}{c c} \hline \hline
**Design** & **Antenna Design** \\ \hline
1 & Connected patch inner and patch outer (CPIO) and split ring resonator with tooth (SWT) \\
2 & Connected patch inner and patch outer (CPIO) and split ring resonator without tooth (SWOT) \\
3 & Disconnected patch inner and patch outer (DCPIO) and split ring resonator with tooth (SWT) \\
4 & Disconnected patch inner and patch outer (DCPIO) and split ring resonator without tooth (SWOT) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Different proposed structures. Figure 6: Measured and simulated reflectance response analysis using the FR-4 as substrate. The number of bands for the proposed four structures is 3, 2, 3 and 1. Minimum reflectance responses are, respectively, \(-26.11\) dB,\(-21.52\) dB, \(-11\) dB and \(-10.10\) dB. The resonance frequency is, respectively, 3.38 GHz, 3.39 GHz, 7.27 GHz and 8.64 GHz.