# Development of a Wideband Slotted Antenna Array with Low Profile and Low Sidelobe
## 5 Conclusions  
A novel K-band slotted cavity antenna array is proposed, which has obvious advantages including wide bandwidth, low profile, and low SLL. The antenna consists of \(16\times 16\) slot antenna elements, which are fed by a Chebyshev power distribution-based 1-64 feeding network to realize the low SLL radiation performance. The Chebyshev power distribution is realized by using a series of unequal-power but equal-phase T-junctions. In order to reduce the complete profile, a simple shallow cavity, which works in the \(TE_{220}\) mode, is designed. The high-order mode cavity is used to generate a resonance to efficiently transmit the power from the feeding network to the radiation slots. Based on the FEM simulation results, the proposed antenna array can provide a gain of 29.1 dBi at the desired center frequency of 20 GHz. Its 3 dB beam-widths in the \(E\)-plane and the \(H\)-plane are 5.46\({}^{\circ}\) and 5.74\({}^{\circ}\), respectively, and its first SLLs in the \(E\)- and \(H\)-planes at 20 GHz are \(-28.3\) dB and \(-24.8\) dB, respectively. Compared to the existing similar studies, very good radiation performance including the aperture efficiency and the SLL is obtained by using the proposed antenna array. Due to the broad bandwidth and small size of the antenna array, it is ready to be integrated with other circuits and systems. Moreover, the design theories proposed in the paper can be used for developing other antennas to achieve very good radiation performance.  
Conceptualization, H.Y.; methodology, H.Y., J.L. and X.B.; theories, H.Y., Z.W. and M.B.L.; simulation analysis, H.Y. and Z.Z.; validation and data analysis, H.Y., G.G. and L.S.; writing--original draft preparation, H.Y., X.B. and G.C.; writing--review and editing, N.D., M.B.L. and G.C.; supervision, X.B. All authors have read and agreed to the published version of the manuscript.  
The work is supported in part by the National Key R&D Program of China (Grant no. 2022 YFF0604801), in part by the National Natural Science Foundation of China under Grant 62201037 and Grant 62271056, and in part by the BIT Youth Academic Start-up Funding XSQD-202206001.  
**Data Availability Statement:** Not applicable.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & **Center Frequency** & \multirow{2}{*}{**BW (\%)**} & \multirow{2}{*}{**Scale**} & **Peak Gain** & **First SLL** & **Aperture Eff** & **Size (Normalized to** \\  & & & & **(dBi)** & **(dB)** & **(\%)** & **\(\lambda_{\textbf{0}}\)**)** \\ \hline
[33] & 9 & 1.6 & \(1\times 10\) & 15.6 & \(-26.3\) & N/A & N/A \\
[5] & 10 & 4 & \(4\times 4\) & 18 & \(-20\) & 72.7 & \(2.92\times 3.27\times 0.25\) \\
[7] & 37.5 & 17.6 & \(8\times 8\) & 24.6 & \(-18\) & 34.8 & \(6.60\times 6.60\times 0.17\) \\
[29] & 7.5 & 31.9 & \(1\times 8\) & N/A & \(-24.7\) & N/A & \(1.05\times 6.25\times 0.24\) \\
[19] * & 60 & 20.3 & \(16\times 16\) & 33.7 & \(\sim\)\(-14\) & 74.3 & \(16.3\times 15.44\times 1.3\) \\
[27] & 15 & 12.6 & \(16\times 16\) & 30.2 & \(-24.1\) & 58.7 & \(12\times 12\times 0.73\) \\
[28] & 77 & 13.2 & \(64\times 32\) & 39.9 & \(-20.2\) & 48.8 & \(56.46\times 28.23\times 1.41\) \\ This work & 20 & 21.9 & \(16\times 16\) & 29.1 & \(-22.5\) & 50.6 & \(11.31\times 11.31\times 0.48\) \\ \hline \hline \end{tabular}
* Based on a uniform feeding network.  
\end{table}
Table 3: Comparison of Previously Reported Antenna Arrays.  
**Acknowledgments:** The authors would like to acknowledge [PERSON] from the University of Science and Technology Beijing for the support in discussing the possibility and technologies for fabrication.  
**Conflicts of Interest:** The authors declare no conflict of interest.