## 4 Conclusions  
In this paper, a novel microstrip-fed monopole printed antenna with quadruple notched bands has been proposed and discussed. The antenna uses a circular radiating patch to achieve broadband characteristics. Two interdigital resonant slots, a curled C-shape slot, and a curled split-ring resonant ring are used to realize quadruple-notched bands. Finally, by adjusting their structural parameters, the antenna achieves notch characteristics of 3.38-3.75 GHz, 5.01-5.25 GHz, 5.63-5.86 GHz, and 7.45-7.82 GH; interference from WiMAX, WLAN, and downlinks of X-band satellite communication are effectively avoided. The antenna shows good omnidirectionality, good gain, and good filtering accuracy in the UWB frequency range. Based on the above considerations, the antenna proposed in this paper is expected to be a good candidate for UWB communication systems.  
[PERSON] participated in the structure design and optimization, data analysis, simulation, and measurement; [PERSON] and [PERSON] participated in background research and feasibility analysis; [PERSON] and [PERSON] provided assistance for writing and revision of the paper. All authors have read and agreed to the published version of the manuscript.  
The project was supported by the Fund of State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications) (No. IPOC2022 ZZ02), China.  
Not applicable.  
The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{\begin{tabular}{c} **UWB** \\ **Band/GHz** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Size/mm\({}^{2}\)** \\ **(Bandwidth)/GHz** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Unwanted Bands** \\ **(Bandwidth)/GHz** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Rejection Bands** \\ **(Bandwidth)/GHz** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Band Error/\%** \\ **Error/\%** \\ \end{tabular} } \\ \hline
[26] & 2.5–11 & 40 \(\times\) 37 & 3.3–3.7 (0.4) & 3.2–3.8 (0.6) & 4.7, N/A & 50 \\
[26] & 2.5–11 & 40 \(\times\) 37 & 5.15–5.35 (0.2) & 5.1–N/A (N/A) & 1, N/A & N/A \\  & & 5.725–5.825 (0.1) & N/A–5.9 (N/A) & N/A, 1.3 & N/A \\ \hline
[27] & 2.9–23.5 & 22 \(\times\) 16 & 5.15–5.35 (0.2) & 5.39–N/A (N/A) & 4.7, N/A & N/A \\  & & 5.725–5.825 (0.1) & N/A–5.9 (N/A) & N/A, 1.3 & N/A \\  & & 7.25–7.75 (0.5) & 7.30–7.75 (0.45) & 0.7, 0 & 10 \\ \hline
[28] & 2.82–13.25 & 22 \(\times\) 13 & 3.3–3.7 (0.4) & 3.19–4.58 (1.39) & 3.3, 23.7 & 247 \\  & & 5.47–5.875 (0.4) & 5.26–6.21 (0.95) & 3.8, 5.7 & 137 \\  & & 7.9–8.4 (0.5) & 7.87–8.73 (0.86) & 0.4, 3.9 & 72 \\ \hline
[29] & 2.76–11 & 32 \(\times\) 30 & 3.3–4.2 (0.9) & 3.45–N/A (N/A) & 4.5, N/A & N/A \\  & & 4.5–4.8 (0.3) & N/A–4.81 (N/A) & N/A, 0.2 & N/A \\  & & 4.15–5.35 (1.2) & 5.24–N/A (N/A) & 26, N/A & N/A \\  & & 5.47–5.725 (0.26) & N/A–6.21 (N/A) & N/A, 8.5 & N/A \\ \hline
[30] & N/A & 30 \(\times\) 26 & 3.4–3.69 (0.29) & 3.21–3.79 (0.58) & 2.7, 2.7 & 100 \\  & & 5.15–5.35 (0.2) & 4.65–5.43 (0.78) & 9.7, 1.5 & 290 \\  & & 7.25–7.75 (0.5) & 7.15–8.07 (3.42) & 1.4, 4.1 & 584 \\ \hline
[31] & 3.57–11.7 & 24 \(\times\) 24 & 3.3–3.8 (0.5) & 3.39–3.92 (0.53) & 2.7, 3.2 & 6 \\  & & 5.15–5.35 (0.2) & 4.43–5.48 (1.05) & 14, 2.4 & 425 \\ \hline
[32] & 3–12 & 32 \(\times\) 40 & 5.1–5.37 (0.27) & 5.05–5.35 (0.3) & 0.9, 0.4 & 11 \\ \hline  & & 3.3–3.7 (0.4) & 3.38–3.75 (0.37) & 2.4, 1.3 & 7.4 \\ This work & 2.9–11 & 35 \(\times\) 30 & 5.15–5.35 (0.2) & 5.01–5.25 (0.24) & 2.7, 1.9 & 8.3 \\  & & 5.725–5.825 (0.1) & 5.63–5.86 (0.23) & 1.6, 0.6 & 120 \\  & & 7.25–7.75 (0.5) & 7.45–7.82 (0.37) & 2.8, 0.9 & 26 \\ \hline \end{tabular}
\end{table}
Table 2: _Cont._