# Compact Broadband Antenna with Vicsek Fractal Slots for WLAN and WiMAX Applications
## 4 Conclusions  
A novel broadband octagonal microstrip patch antenna with Vicsek fractal slots suitable for WLAN and WiMAX applications is proposed. This antenna is printed in FR-4 substrate with dimensions of 50 \(\times\) 50 \(\times\) 1.6 mm\({}^{3}\). The measurement results confirm that this antenna has a broadband 2.48 to 6.7 GHz and two resonant frequencies of 3.6 and 5.3 GHz, respectively, which cover the WiMAX bands (2.3/2.5/3.3/3.5/5/5.5 GHz) and WLAN bands (2.4-2.5/3.6/4.9-5.9 GHz). This antenna achieves considerable peak gains, 2.78 and 5.32 dBi, and radiation efficiencies 88.5 and 84.6% at the resonant frequencies. Moreover, the proposed antenna offers an omnidirectional radiation pattern in the H-plane and in the E-plane. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Antenna** & **Simulated (CADFEKO)** & **Simulated (CST)** & **Measured** \\
**Performance** & & & & & & \\ \hline \(f_{r}\) (GHz) & 3.5 & 5.1 & 3.6 & 5.2 & 3.6 & 5.3 \\ \hline \(S_{11}\) (dB) & \(-\)23.3 & \(-\)23.9 & \(-\)42.7 & \(-\)50.06 & \(-\)41.3 & \(-\)57.2 \\ \hline Gain (dBi) & 2.63 & 5.26 & 2.7 & 5.36 & 2.78 & 5.32 \\ \hline Bandwidth (GHz) & & 4.15 & & 4.35 & & 4.22 \\ \hline \end{tabular}
\end{table} 
Table 2: Summary of simulation and measurement results of the suggested antenna. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Ref No.** & **Size (mm2)** & **Type of** & **Frequency** & **Bandwidth** & **Resonant** & **Peak Gain** \\  & **Substrate** & **Range (GHz)** & **(GHz)** & **Frequency (GHz)** & **(dBi)** \\ \hline
[17] & 60 \(\times\) 90 & FR-4 & 2.3–3 & 4.7–6 & 0.7, 1.3 & 2.4, 5.2, 5.6 & 4.76, 2.9, 2.44 \\ \hline
[18] & 57 \(\times\) 31.2 & FR-4 & 2.3–2.6 & 2.9–3.8 & 0.3, 0.9, 0.85 & 2.45, 3.5, 5.5 & 1.19, 1.59, 2.39 \\  & & & 4.8–5.65 & & & & \\ \hline
[19] & 56 \(\times\) 37 & FR-4 & 2.24–2.5 & 3.6–3.99 & 0.26, 0.39, 0.2, 0.19 & 2.43, 3.83, 4.48, 5.8 & 2.2, 2.8, 3.3, 4.2 \\  & & & 5.71–5.9 & & & & \\ \hline
[20] & 60 \(\times\) 60 & FR-4 & 2.3–2.6 & 2.3–2.6 & 0.3, 0.4 & 2.46, 3.5 & 2.61, 2.7 \\ \hline
[21] & 120 \(\times\) 70 & Taconic RF-35 & 2.2–4.18 & 1.98 & 2.46, 3.5 & 4.11, 6.48 \\ \hline
[22] & 60 \(\times\) 45 & FR-4 & 2.25–2.95 & 0.7, 0.26 & 2.6, 3.5 & 7.1, 7.3 \\
**This work** & **50 \(\times\) 50** & **FR-4** & **2.48–6.7** & **4.22** & **3.6, 5.3** & **2.78, 5.32** \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of the suggested antenna performances with other antennas in the literature. **Author Contributions:** Conceptualization, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L.; data curation, O.B., S.A., M.S., K.C., A.R. and A.G.; formal analysis, O.B., S.A., M.S., K.C., A.R., A.G. and M.A. ; funding acquisition, M.A. and E.L.; investigation, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L.; methodology, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L.; project administration, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L.; software, O.B., S.A., K.C., A.R. and A.G.; supervision, A.G., M.A. and E.L.; validation, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L.; visualizing, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L.; writing-original draft, O.B., S.A., A.G.; writing-review and editing, O.B., S.A., M.S., K.C., A.R., A.G., S.K., M.A. and E.L. All authors have read and agreed to the published version of the manuscript. This project has received funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538. Also, the work was partially supported by the Researchers Supporting Project number (RSP-2021/58), King Saud University, Riyadh, Saudi Arabia. Not applicable. **Data Availability Statement:** All data are included within the manuscript. **Acknowledgments:** The authors appreciate the funding from Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant 801538.