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.