## 3 Result and Discussion
Figure 10 represents the directivity vs. the degree plot using Rogers RT Duriod 5880 as the substrate (\(-180^{\circ}\) to \(+180^{\circ}\)). Figure 10a,b show that the CPIO and SWT modes represent the maximum directivity of 6.86 dB and the normalized directivity of 24\({}^{\circ}\) (\(-16\) to \(+8\)). The CPIO and SWOT models represent the maximum directivity of 6.84 dB and the normalized directivity of 15\({}^{\circ}\) (\(-49\) to \(-35\)), 25\({}^{\circ}\) (\(-19\) to \(+4\)), and 14\({}^{\circ}\) (\(+23\) to \(+37\)). The DCPIO and SWT modes represent the maximum directivity of 4.47 dB and the normalized directivity of 32\({}^{\circ}\) (\(-43\) to \(-11\)). The DCPIO and SWOT models represent the maximum directivity of 4.74 dB and the normalized directivity of 32\({}^{\circ}\) (\(-43\) to \(-11\)). The DCPIO and SWOT models represent the maximum directivity of 4.74 dB and the normalized directivity of 4.74 dB and the normalized directivity of 29\({}^{\circ}\) (\(-43\) to \(-14\)). The antenna's gain effectively represents the conversation of an applied electric signal into the electromagnetic waves. Figure 11 illustrates a total gain for the proposed four structures using the FR4, respectively, 4.54 dB, 3.51 dB, 2.39 dB and 2.38 dB. Figure 12 represents a total gain for the proposed four structures using Rogers RT Duroid 5880, respectively, 8.57 dB, 8.34 dB, 7.76 dB, and 7.47 dB. The comparison of the total gain for the proposed four antenna structures using the different substrate materials are represented in Table 4. The comparison of proposed design with another multiband design is represented in the Table 5.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Design** & **No of** & **Reflectance** & **Resonance** & **VSWR** & **Bandwidth** & **Starting** & **Ending** \\  & **Bands** & **Response (S\({}_{11}\))** & **Frequency (GHz)** & **VSWR** & **(GHz)** & **Point (GHz)** & **Point (GHz)** \\ \hline CPIO and SWT & 3.00 & \(-26.11\) & 3.38 & 1.51 & 0.13 & 3.32 & 3.45 \\  & & \(-15.70\) & 4.66 & 5.21 & 0.22 & 4.59 & 4.81 \\  & & \(-12.30\) & 5.56 & 8.00 & 0.11 & 5.50 & 5.61 \\  & & \(-21.52\) & 3.39 & 1.18 & 0.06 & 3.36 & 3.42 \\  & & \(-15.60\) & 4.64 & 1.39 & 0.07 & 4. Figure 8: **(a)** The minimum value of the VSWR for the proposed four antenna structures by selecting the substrate as FR4, is 1.51 at 3.38 GHz, 1.18 at 3.39 GHz, 1.83 at 7.27 GHz, respectively, and 2.21 at 8.64 GHz. **(b)** The minimum value of the VSWR for the proposed four antenna structures by selecting the substrate as Rogers RT Duroid 5880 are 1.05 at 6.49 GHz, 1.03 at 6.52 GHz, 2.33 at 8.83 GHz and 5.67 at 8.80 GHz. Figure 9: Maximum directivity and the normalized directivity for all of the modes are, respectively, 5.59 dB with 81\({}^{\circ}\), 3.77 dB with 93\({}^{\circ}\), 3.35 dB with 21\({}^{\circ}\), 18\({}^{\circ}\), 13\({}^{\circ}\) and 3.34 dB with 23\({}^{\circ}\), 17\({}^{\circ}\), 14\({}^{\circ}\). Figure 10: Directivity plot using the Rogers RT Duroid 5880 substrate for the range of \(-180^{\circ}\) to \(+180^{\circ}\). The maximum directivity and the normalized directivity for all of the modes are 6.86 dB with \(24^{\circ}\) and \(7^{\circ}\), 6.84 dB with \(15^{\circ}\), \(25^{\circ}\), \(14^{\circ}\), and 4.47 dB with \(32^{\circ}\) and 4.74 dB with \(29^{\circ}\). Figure 11: Total gain for the presented four antenna structures by selecting the substrate FR4. (a) 4.54 dB for the CPIO and SWT (b) 3.51 dB for the CPIO and SWOT (c) 2.39 dB for the DCPIO and SWT (d) 2.38 dB for the DCPIO and SWOT. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Design**} & \multicolumn{2}{c}{**Substrate**} \\ \cline{2-3}  & **Rogers RT Duroid 5880** & **FR4** \\ \hline CPIO and SWT & \(8.57\) & \(4.54\) \\ CPIO and SWOT & \(8.34\) & \(3.51\) \\ DCPIO and SWT & \(7.76\) & \(2.39\) \\ DCPIO and SWOT & \(7.47\) & \(2.38\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Total gain for the two different substrates, Rogers RT Duroid 5880 and FR4.