A Wideband Omni-directional Antenna Based on Printed Log-Periodic Element

Abstract

In this paper, a novel omni-directional antenna with wideband and low cross-polarization for GSM1800/3G/LTE/5G indoor communication systems is proposed. By using the printed log-periodical antenna elements, which are evenly arranged around the center, the proposed antenna achieves the omnidirectional radiation patterns. Moreover, with the cooperation of the log-periodical antenna and the annular parasitic patches, a wide bandwidth and a good omnidirectional radiation performance are achieved simultaneously. Simulated results indicate that an impedance bandwidth of 1.7-3.8 GHz (76.4%) can be achieved with a gain of approximately 1.5 dBi across the whole operating frequency. Low cross-polarization level of less than −30 dB and compact size are also acquired.