# X-Band Photonic-Based Pulsed Radar Architecture with a High Range Resolution
## 4 Conclusions  
In this paper, we proposed a photonic-based pulsed radar architecture to improve range resolution than the range resolution of the previous pulsed radar using a CW laser source. By adding an MZM, \begin{table}
\begin{tabular}{c c c c c c c} \hline  & \begin{tabular}{c} **Frequency** \\ **Band** \\ \end{tabular} & \begin{tabular}{c} **Bandwidth** \\ **(MHz)** \\ \end{tabular} & \begin{tabular}{c} **Range** \\ **Resolution (cm)** \\ \end{tabular} & \begin{tabular}{c} **Maximum** \\ **Range (m)** \\ \end{tabular} & \
\begin{tabular}{c} **Optic Source Type** \\ \end{tabular} &
\begin{tabular}{c} **Radar Type** \\ **Radar Type** \\ \end{tabular} \\ \hline
[9] & \(X\)-band & 200 & 75 & 5500 & MLL & Pulsed \\ \hline
[18] & \(X\)-band & 40 & 375 & 14816 & MLL & Pulsed \\ \hline
[19] & \(S\)-, \(X\)-band & 40 & 375 & 14816 & MLL & Pulsed \\ \hline
[20] & \(S\)-, \(X\)-band & 40 & 375 & 33336 & MLL & Pulsed \\ \hline
[21] & \(K\)-band & 8000 & 1.875 & 3.5 & CW laser & FMCW \\ \hline
[22] & \(W\)-band & 8000 & 1.875 & 0.85 & CW laser & FMCW \\ \hline
[8] & \(S\)-, \(X\)-band & 20 & 750 & 400 & MLL & Pulsed \\ \hline
[23] & \(K\)-band & 8000 & 1.875 & 4 & CW laser & FMCW \\ \hline
[24] & \(S\)-, \(X\)-band & 18 & 833 & 1650 & MLL & Pulsed \\ \hline
**This work** & \(X\)**-band** & **640** & **23.4** & **520** & **CW laser** & **Pulsed** \\ \hline \end{tabular}
\end{table} 
Table 1: Comparison of the key performances with the previous photonic-based radar. Figure 7: Target history and high-resolution range profiles of two moving targets. (**a**) Target history of when targets are at the initial position. (**b**) Target history of when targets are at the same range. (**c**) High-resolution range profiles according to the distance between two targets. which is controlled as an optical switch, the CW laser source based FMCW radar can be operated as a pulsed radar with maintain the advantage of the broad bandwidth. To confirm the feasibility of the proposed architecture as a pulsed radar system, the prototype is implemented and evaluated through the indoor experiments. For the indoor test, two metal plates measuring 0.2 m \(\times\) 0.2 m are used for targets. Their positions are detected in real-time with 1.6% of an accuracy error rate, and the range resolution was quite approximated to the theoretical value. Thus, it is confirmed that the proposed pulsed radar architecture can be sufficiently applied to a photonic-based pulsed radar system with wide signal bandwidth. The proposed architecture could be adopted in application for the photonic-based pulsed Doppler radar system for high-resolution surveillance in the future. Conceptualization, J.S. and Y.B. ; methodology, M.Y. and Y.B. ; software, M.Y. ; validation, Y.B., M.Y. ; formal analysis, J.S. and Y.B. ; investigation, J.S. ; resources, J.S. ; data curation, M.Y. and Y.B. ; writing--original draft preparation, Y.B. ; writing--review and editing, J.S. and S.-G.L. ; visualization, Y.B. and S.-G.L. ; supervision, J.S. ; project administration, J.S. ; funding acquisition, J.S. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The authors declare no conflict of interest. The following abbreviations are used in this manuscript: