# A VHF Band Small CRLH Antenna Using Double-Sided Meander Lines
## 4 Conclusions  
In this paper, we proposed a miniaturized antenna based on a CRLH transmission line in the VHF band using meander lines at both the top and bottom. The proposed antenna was miniaturized by using the zeroth-order resonant frequency of the CRLH transmission line, and the meander lines connected to the top and bottom were used to increase the parallel inductance. The unit cell consisted of an interdigital capacitor and a meander line, and was designed to increase the length of the meander line as the number of cells increases. The size of the unit cell was \(0.01\times\)\(0.02\times\)\(0.0003\lambda\) (\(37\times 70.6\times 1\) mm\({}^{3}\)). Antennas with 3-, 5-, and 7-unit cells were designed, and it was confirmed that the gain of the antenna increases as the number of unit cells increases. The optimized antenna consisted of 7-unit cells and operated at 84 MHz. The overall size of the antenna was \(0.087\times\)\(0.02\times\)\(0.0003\lambda\) (\(308.1\times 70.6\times 1\) mm\({}^{3}\)). The antenna had a bandwidth of 2% (83.7-85.4 MHz) and an antenna gain of \(-22.7\) dBi. Therefore, the proposed antenna can be used for military applications operating in the VHF band without increasing the physical size of the antenna. We will conduct a study to improve the bandwidth of the proposed antenna.  
Conceptualization, S.L. and Y.B.P.; methodology, S.L.; software, S.L.; validation, S.L.; formal analysis, S.L.; investigation, S.L.; resources, S.L.; data curation, S.L.; writing--original draft preparation, S.L.; writing--review and editing, S.L. and Y.B.P.; visualization, S.L.; supervision, Y.B.P.; project administration, Y.B.P.; funding acquisition, Y.B.P. All authors have read and agreed to the published version of the manuscript.  
This work has been supported by the Future Combat System Network Technology Research Center program of Defense Acquisition Program Administration and Agency for Defense Development (UD190033 ED).  
Not applicable.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Reference**} & \multirow{2}{*}{**Antenna Size**} & **BW** & **Antenna Gain** \\  & & **(VSWR 3.5:1)** & \\ \hline \multirow{2}{*}{[1]} & 0.13\(\lambda\) & 100\% & \(-\)10 dBi \\  & (1300 mm) & (30–90 MHz) & (average gain) \\ \hline \multirow{2}{*}{[3]} & 0.234\(\lambda\) & 98\% & 2 dBi \\  & (2340 mm\({}^{3}\)) & (30–88 MHz) & (@88 MHz) \\ \hline \multirow{2}{*}{[15]} & 0.14\(\lambda\times\) 0.16\(\lambda\times\) 0.01\(\lambda\) & 4.1\% & \(-\)6.9 dBi \\  & (24.8 \(\times\) 22 \(\times\) 1.5 mm\({}^{3}\)) & (1910–1990 MHz) & (@1950 MHz) \\ \hline \multirow{2}{*}{[23]} & 0.021\(\lambda\times\) 0.017\(\lambda\) \(\times\) 0.002\(\lambda\) & 5\% & \(-\)38 dBi \\  & (24.8 \(\times\) 22 \(\times\) 1.5 mm\({}^{3}\)) & (395–415 MHz) & (@402 MHz) \\ \hline \multirow{2}{*}{[24]} & 0.103\(\lambda\times\) 0.043\(\lambda\times\) 0.008\(\lambda\) & 5\% & \(-\)26.5 dBi \\  & (191.4 \(\times\) 80 \(\times\) 1.52 mm\({}^{3}\)) & (158–166 MHz) & (@160 MHz) \\ \hline Proposed & 0.087\(\lambda\) 0.02\(\lambda\) \(\times\) 0.0003\(\lambda\) & 2\% & \(-\)22.7 dBi \\ Antenna & (308.1 \(\times\) 70.6 \(\times\) 1 mm\({}^{3}\)) & (83.7–85.4 MHz) & (@84 MHz) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Comparison of the antenna performance with the previous work.