Abstract: A dual-polarized radiation unit for an antenna includes: four dipoles, wherein radiation arms of the four dipoles are configured in relation to two mutually perpendicular lines, wherein the two mutually perpendicular lines divide the radiation unit into four regions, and a center portion of the four regions is direct current-conducting, and wherein each of the four regions has a hollow region.

Abstract: A base station antenna includes a smart bias tee (SBT), an antenna array, a phase shifter, and a filter circuit. The antenna array includes a plurality of antenna elements. The phase shifter includes a plurality of output terminals. Each of the plurality of output terminals is coupled to an antenna element. The filter circuit includes a first filter. An input terminal of the first filter is coupled to either one of output terminals of two ends of the phase shifter. The output terminals are coupled to the SBT. The output terminals of the two ends of the phase shifter have weaker power compared to other output terminals.

Abstract: A base station antenna includes a smart bias tee (SBT), an antenna array, a phase shifter, and a filter circuit. The antenna array includes a plurality of antenna elements. The phase shifter includes a plurality of output terminals. Each of the plurality of output terminals is coupled to an antenna element. The filter circuit includes a first filter. An input terminal of the first filter is coupled to either one of output terminals of two ends of the phase shifter. The output terminals are coupled to the SBT. The output terminals of the two ends of the phase shifter have weaker power compared to other output terminals.