# A VHF Band Small CRLH Antenna Using Double-Sided Meander Lines
###### Abstract  
In this paper, a miniaturized very-high frequency (VHF) band antenna using both top and bottom meander lines is proposed. To design a compact size antenna in the VHF band, a Composite Right/Left-Handed (CRLH) transmission line is applied to antenna structure; additionally, both top and bottom meander lines were used to achieve a greater inductance. The CRLH transmission line unit cell operates at 88 MHz, and the fabricated antenna is designed by arranging 7-unit cells. The overall size of the proposed antenna is 0.087\(\lambda\)\(\times\) 0.022 \(\times\) 0.0003\(\lambda\) at the lowest operating frequency, and the antenna operates at 84 MHz. The VSWR 3.5:1 reference operating bandwidth of the antenna is 2%. The received power of the proposed CRLH antenna was measured to verify the antenna performance.  
composite right/left-handed transmission lines; military antenna; VHF (very high-frequency); meander lines +
Footnote †: journal: Applied  
The CRLH TL antenna in previous studies implemented a series capacitor using the gap between patch and patch [8; 9; 12; 16; 19] or IDC (Interdigital Capacitor) [13; 15; 24; 25]. A parallel inductor was implemented by connecting the via [8; 9; 13; 16], spiral inductor [20; 24; 25], or meander line [6; 9; 13; 14; 15; 19] located at the top of the antenna to the ground located at the bottom. When designing an open-ended antenna, most of the previous studies have been conducted in the UHF band because there is a limit to achieving a greater parallel inductance with the previous antenna structure [4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22]. There was also research on open-ended antenna using CRLH TL in the VHF band [23; 24], but it is difficult to design an antenna operating at frequencies lower than 100 MHz using a spiral inductor and a meander line that exist only at the top. This is because the length of the inductor increases to operate at a low frequency, and, consequently, the physical size of the antenna increases. We need a miniaturized antenna structure for military applications operating in the VHF band. That is, a new CRLH TL unit cell structure having a greater parallel inductance without increasing the physical size is required.  
In this paper, we propose 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 consists of an interdigital capacitor and a meander line. In addition, the antenna is designed to increase the length of the meander line as the number of cells increases. The size of the unit cell is 0.01\(\lambda\)\(\times\) 0.02\(\lambda\)\(\times\) 0.0003\(\lambda\) (37 \(\times\) 70.6 \(\times\) 1 mm\({}^{3}\)), and the size of the fabricated 7-unit cell antenna is 0.087\(\lambda\)\(\times\) 0.02\(\lambda\)\(\times\) 0.0003\(\lambda\) (308.1 \(\times\) 70.6 \(\times\) 1 mm\({}^{3}\)) at 84 MHz. The proposed antenna was designed using an ANSYS high-frequency structure simulator (HFSS) and its performance was verified through simple measurement. The designs of the CRLH transmission line unit cell and antenna are described in Section 2. In Section 3, the simulated and measured results of antenna are introduced and compared. Finally, Section 4 concludes the paper.