Dual polarized wide band antenna fed by triplate line for celluar base stations

Wide band antenna elements consisting of a loop slot and double layered parasitic patches are designed for the cellular base station antennas to cover the frequency band of 698 to 960MHz. This antenna is excited by triplate transmission line, eliminating feeding coaxial cables and connectors inside base station antenna. Low input VSWR less than 1.5 and high isolation between dual-polarization feeding ports more than 20dB are obtained for ±45° slant diversity antenna. This paper describes the design of this antenna element and 4-element array characteristics.