Design of base-station antennas with stable radiation patterns

The methods to design base-station antennas with stable radiation patterns in broadband are presented. Through a rational place of two dipoles in parallel configuration or in orthogonal over a reflector, the antennas with a wide impedance bandwidth, stable radiation pattern and nearly identical E- and H-plane can be achieved due to the complementation of the radiation patterns. According to these method, multi-dipole antennas with about 60% impedance bandwidth (SWR<;1.5) and stable radiation patterns of 3-dB beamwidth 63±3 degree are achieved.