This paper presents a small VHF antenna using a composite right/left-handed (CRLH) transmission lines. The proposed antennas have 3 and 7 unit cells that consist of interdigital capacitors and shunt spiral inductors. The size of the antenna with 3 unit cells is 0.039λ × 0.025λ × 0.0008λ (72.9 × 47.5 × 1.52 mm3) at 161 MHz and its peak gain is − 33 dBi. To enhance the gain, the antenna with 7 unit cells is fabricated. Its size is 0.089λ × 0.025λ × 0.0008λ (167.2 × 47.5 × 1.52 mm3) at 161.4 MHz and its peak gain is − 26.5 dBi. The radiation pattern of both antennas is omni-directional. The electrical size in kr of each antenna is 0.055 and 0.11, respectively. The effects of frequency characteristic of lumped elements on the impedance matching are discussed.
Acknowledgements 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 (UD160070BD).
