# A Low-Cost CPW-Fed Multiband Frequency Reconfigurable Antenna for Wireless Applications
## 3 Results and Discussions
### Case 1: (All Switches ON)  
The measured and simulated S\({}_{11}\) in Case 1 are shown in Figure 9. All the switches are ON in this case; thus, current pass through the longest path and all parts of the antenna radiates. In this mode, the antenna resonates at four different operating bands from 2.2 GHz to 9.7 GHz. This band has almost same radiation pattern, i.e., the omnidirectional pattern in H-plane and bidirectional in E-plane, as all its frequency bands, so a radiation pattern that is appropriate for all frequencies is selected for inclusion in the paper. This antenna is an excellent choice for integration into portable devices for wireless communication. Figure 10 shows the radiation pattern for all switches in the ON state.  
The first band is from 2.2 GHz to 3.4 GHz with a mid-operating frequency of 2.7 GHz and an impedance bandwidth of 1200 MHz. It covers the WLAN standards of 2.4 GHz to 2.484 GHz and WiMAX standards of 2.5 GHz to 2.69 GHz. The second band is from 3.8 GHz to 4.7 GHz with an operating frequency of 4.4 GHz and an impedance bandwidth of 900 MHz. This band covers a part of the S-band. The S-band is used for weather radar, surface ship radar, and some communications  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Case**} & \multicolumn{3}{c}{**Diodes**} & \multicolumn{3}{c}{**Frequency Bands**} & \multicolumn{2}{c}{**Operating**} & \multirow{2}{*}{**No. of**} \\ \cline{2-2} \cline{5-8}  & **S2** & **S3** & **S4** & **S5** & & **(GHz)** & & **Frequency (GHz)** & **Bands** \\ \hline
1 & 1 & 1 & 1 & 1 & 1 & 2.2–3.4, 3.8–4.7, 7.8–8.4, 9.2–9.7 & 2.7, 4.4, 8.1, 9.4 & 4 \\
2 & 0 & 0 & 0 & 0 & 2.1–3.3, 3.6–4.3, 5.2–5.46, 6.4–6.8, 8.4–8.8 & 2.7, 4.1, 5.4, 6.6, 8.6 & 5 \\
3 & 1 & 0 & 1 & 0 & 2.2–3.3, 3.7–4.4, 5.2–5.6, 6.7–7.2, 8.4–9.2 & 2.7, 4.1, 5.4, 6.9, 8.8 & 5 \\
4 & 1 & 1 & 0 & 0 & 2.2–3.3, 3.7–4.5, 8.1–8.8 & 2.7, 4.2, 8.4 & 3 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Different configurations of pin diodes and their corresponding operating bands.  
Figure 10: Measured and simulated radiation pattern for all switches ON.  
Figure 9: Measured and simulated S\({}_{11}\) for all switches ON.  
satellites (WLAN, Bluetooth, ZigBee, radio astronomy, microwave devices/communications, mobile phones, GPS, amateur radio).  
The C-band is used for long-distance radio telecommunications. Mostly 4.4 GHz is used for defense communication. The third band achieved is from 7.8 GHz to 8.4 GHz with an operating frequency of 8.1 GHz and an impedance bandwidth of 600 MHz. This band covers an essential part of the X-band for wireless communication. It includes the military demand for satellite uplinks and the mobile satellite sub-band from 7.9 GHz to 8 GHz for naval and land mobile satellite earth stations. The military requirement for earth exploration satellite (downlink) purposes is in the band from 8 GHz to 8.4 GHz. The last band, in this case, starts from 9.2 GHz and ends at 9.7 GHz with an operating frequency of 9.4 GHz and an impedance bandwidth of 500 MHz. It is used for satellite communications, radar, terrestrial broadband, space communications, and amateur radio. The summarized results of this case are presented in Table 3.