# A Low-Cost CPW-Fed Multiband Frequency Reconfigurable Antenna for Wireless Applications
## 3 Results and Discussions
### Case 3: (Switches 2 and 4 ON, Switches 3 and 5 OFF)  
The measured and simulated S\({}_{11}\) in Case 3 are shown in Figure 13. Switches 2 & 4 are ON in this case, whereas switches 3 & 5 are OFF; thus, current passes through the upper part of the antenna only. In this mode, the antenna resonates at five different operating bands with an impedance bandwidth of 2.2 GHz to 9.2 GHz. The radiation pattern of this case shows the same behavior, having an omnidirectional pattern in the H-plane and a bidirectional pattern in the E-plane, as shown in Figure 14.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Freq.(GHz)** & 2.7 & 4.1 & 5.4 & 6.6 & 8.6 \\ \hline
**RL (dB)** & \(-29\) & \(-23\) & \(-14\) & \(-19\) & \(-18\) \\ \hline
**BW (MHz)** & 1200 & 700 & 260 & 400 & 400 \\ \hline
**Gain (dBi)** & \(1.55\) & 1.7 & 0.64 & 0.94 & 2.34 \\ \hline
**Dir. (dB)** & \(1.62\) & 1.9 & 0.8 & 1.10 & 2.6 \\ \hline
**Eff. (\%)** & 95 & 88 & 77 & 85 & 87 \\ \hline
**VSWR** & 1.2 & 1.02 & 1.03 & 1.011 & 1.04 \\ \hline
**App.** & Aviation Service & WiMAX & WLAN & Long Dist. Radio Comm. & X-Band Sat. Comm. \\ \hline \hline \end{tabular}
\end{table}
Table 4: Summarized results of Case 2.  
Figure 12: Measured and simulated radiation pattern for all switches OFF.  
In this case, the first three bands are similar to the previous cases but with slight differences. The fourth band ranges from 6.7 GHz to 7.2 GHz with an operating frequency of 6.9 GHz and an impedance bandwidth of 500 MHz. This band supports fixed satellite communication and WiMAX applications. The last band covers 8.4 GHz to 9.2 GHz with an operating frequency of 8.8 GHz and an impedance bandwidth of 800 MHz. This band is used for satellite and space communications. Table 5 shows the summarized results of this case.  
Regarding Case 2 and Case 3, the applications of both cases are different since the variation in frequency is very minor, i.e., Case 2 antennas can be used for aviation services, WiMAX, WLAN,  
Figure 14: Measured and simulated radiation pattern for switches 2 and 4 ON, switches 3 and 5 OFF.  
Figure 13: Measured and simulated S\({}_{11}\) for switches 2 and 4 ON, switches 3 and 5 OFF.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Freq. (GHz)** & 2.7 & 4.1 & 5.4 & 6.9 & 8.8 \\ \hline
**RL (dB)** & \(-\)39 & \(-\)18 & \(-\)17 & \(-\)13 & \(-\)23 \\ \hline
**BW (MHz)** & 1100 & 700 & 400 & 500 & 800 \\ \hline
**Gain (dBi)** & 1.35 & 1.7 & 0.65 & 1.53 & 2.5 \\ \hline
**Dir. (dB)** & 1.55 & 1.98 & 0.80 & 1.7 & 2.9 \\ \hline
**Eff. (\%)** & 87 & 85 & 82 & 89 & 88 \\ \hline
**VSWR** & 1.4 & 1.09 & 1.02 & 1.04 & 0.9 \\ \hline
**App.** & S-band & \begin{tabular}{c} Aeronautical \\ Radio Navi. \\ \end{tabular} & \begin{tabular}{c} WiMAX \\ \end{tabular} & \
\begin{tabular}{c} FixedSat./ \\ WiMAX \\ \end{tabular} &
\begin{tabular}{c} Sat./Space \\ Comm. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 5: Summarized results of Case 3.  
long distance radio communication, and X-band satellite communication, while Case 3 antennas can be used for S-band applications, WiMAX, aeronautical radio navigation services, and X-band satellite communication.