# A Compact Size Antenna for Extended UWB with WLAN Notch Band Stub
## 5 Conclusions  
A CPW-fed antenna with compact dimensions of 15 mm \(\times\) 10 mm \(\times\) 0.254 mm for WLAN notch band UWB application was presented. The antenna consists of simple geometry with a modified rectangular shaped radiator loaded with a Y-shaped radiator, improving impedance bandwidth ranges 3-14.55 GHz. Hereafter, an additional stub was loaded to achieve WLAN band rejection capability. The proposed antenna offers key features of compact dimensions, wide bandwidth, and moderate gain. This UWB antenna also has band rejection at 4.59-5.82 GHz, thereby reducing the interference with the WLAN band. The specific notched band channel is the most congested part of the WLAN band spectrum 4.9 GHz (802.11j) and 5 GHz (802.11a/h/j) from channel 7 to channel 161. This spectrum is attenuated for reducing the interference with the UWB spectrum. The antenna offers a stable radiation pattern with a gain of more than 2 dBi in the pass band, while for the notch band, a minimum gain of -3.9 dB was observed. The measurement results of the fabricated antenna are well-matched to the simulation results. Moreover, the presented antenna overperforms the literature work by offering a compact size, having a notched band, a simple geometrical configuration, a moderate gain, and an ultra-wide impedance bandwidth. Therefore, the presented antenna is a worthy candidate for utilization in UWB applications where WLAN band rejection is a vital requirement for operation. Conceptualization, methodology, software, validation, and formal analysis, S.N.R.R. and N.H.; investigation, resources and data curation, D.C., S.G.P. and N.K. ; writing--original draft preparation, S.N.R.R. and W.A.A. ; writing--review and editing, D.C., N.H., S.G.P. and N.K. ; supervision, project administration and funding acquisition, N.K. All authors have read and agreed to the published version of the manuscript. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & **Dimensions** & **Frequency Range** & **Rejection Band** & **Peak Gain** & **Design** \\  & **(\(\mathbf{\Omega_{o}\times\lambda_{o}\times\lambda_{o}}\))** & **(GHz)** & **(GHz)** & **(GHz)** & **(dBi)** & **Methodology** \\ \hline
[15] & 0.3 \(\times\) 0.31 \(\times\) 0.02 & 2.9–14.5 & 3.1–3.6/4.9–6.1 & No. Info. & Slot and SRR-loaded \\
[16] & 0.21 \(\times\) 0.21 \(\times\) 0.02 & 3.04–10.87 & 5.03–5.94 & 4.2 & Antenna \\
[17] & 0.29 \(\times\) 0.33 \(\times\) 0.08 & 2.88–12.67 & 3.43–3.85/5.26–6.01 & 4.6 & Slot and SRR-loaded \\
[18] & 0.32 \(\times\) 0.30 \(\times\) 0.005 & 2.95–10.75 & 5.01–6.19 & 5.2 & Filter-loaded \\  & & & & Antenna \\  & & & & Capacitor-loaded \\
[19] & 0.25 \(\times\) 0.32 \(\times\) 0.02 & 3.1–11.2 & 3.3–4.2/6.6–7.6 & 5.1 & Patch \\
[20] & 0.255 \(\times\) 0.222 \(\times\) 0.02 & 3–11 & None & 4.1 & Jug-shaped \\  & & & & Monopole Patch \\
[21] & 0.17 \(\times\) 0.27 \(\times\) 0.02 & 3.1–12.5 & 5–6 & 4.5 & EBG-backed \\  & & & & Monopole Patch \\  & & & & Metamaterial- \\
[22] & 0.148 \(\times\) 0.226 & 3.08–14.1 & None & 4.54 & backed \\  & & & & Antenna \\
[23] & 0.44 \(\times\) 0.32 \(\times\) 0.08 & 3.25–13 & 5.7–6.2 & 6.7 & Octagonal Star-Like \\  & & & & Patch \\
[24] & 0.32 \(\times\) 0.3 \(\times\) 0.02 & 3.58–14.1 & None & 3.2 & Slotted CPW-Fed \\  & & & & Antenna \\
[25] & 0.24 \(\times\) 0.31 \(\times\) 0.01 & 3.4–11.9 & 4.5–5.3/7.2–9 & 3.9 & Stub-loaded Planet \\  & & & & Patch \\ This Work & 0.11 \(\times\) 0.19 \(\times\) 0.002 & 3–14.55 & 4.59–5.82 & 4.93 & Stub-loaded Printed \\  & & & & Antenna \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Performance comparison of the proposed antenna with existing UWB antennas in the literature. **Funding:** This work was supported by the Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Korean government (MSIT) (No. 2022-0-01031, Development of measured EMF big data analysis and management platform). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.