Broadband Polarization Diversity Base Station Antenna for 3G Communication System

Antennas with dual linear slant polarization over a wide band are necessary for modern personal communication base-station applications. A plusmn45deg polarization diversity antenna element constructed by novel umbrella-shaped dipoles is presented in this paper. The antenna has a half-power beam width of 63deg plusmn5deg in the horizontal plane by designing a reflector over a bandwidth of 1710 to 2170MHz, which covers not only 3G frequency band(1920-2170MHz) but also DCS band (1710-1880MHz) and PCS band (1850-1990MHz). In addition the worst-case isolation between polarizations is 30dB and the front-to-back ratio is more than 30dB over the above frequency band.