Landstorfer Printed Log-Periodic Dipole Array Antenna With Enhanced Stable High Gain for 5G Communication

A novel wideband stable high-gain Landstorfer printed log-periodic dipole array (PLPDA) antenna loaded with zero-index metamaterials (ZIMs) is proposed for wireless communication system. Based on the Landstorfer-shaped method, the dipoles and ground of the PLPDA antenna are Landstorfer-shaped and strung together by feeding lines to form a novel Landstorfer PLPDA antenna, which obtains a gain enhancement compared with the PLPDA antenna. To further enhance both the antenna gain and gain flatness, a series of novel ZIM are added to the shorter end of the Landstorfer PLPDA antenna. As an example, four-element Landstorfer PLPDA antennas with/without ZIM are designed, implemented, and measured in Ka-band for 5G application. Compared with the original PLPDA antenna, the proposed Landstorfer PLPDA antenna exhibits a maximum gain enhancement of 2.2 dB within the operating band of 26.5–40 GHz. Loaded with ZIM, the antenna gain can be further improved by 0.5–1.9 dB with a measured gain flatness of 10.5 ± 0.5 dBi over the band of 25.7–40 GHz while the size of antenna keeping unchanged. The proposed antenna presents a stable high-gain performance in terms of the parameter
$\Delta G$
/BW (
$\Delta G$
is the gain variation, BW is the bandwidth) less than 0.07 within the whole Ka-band.