Abstract: A base station antenna is disclosed. The base station antenna includes a feed mechanism and at least one antenna module. Each antenna module includes at least two antenna units, and each antenna unit has a first sub-radiation phase slope. In each antenna module, first sub-radiation phase slopes of the at least two antenna units are different, and each antenna unit is connected to the feed mechanism through a corresponding feeder that is in a one-to-one correspondence with the antenna unit, where the feeder has a second sub-radiation phase slope. The antenna unit and the corresponding feeder form one radiating element, and a radiation phase slope of each radiating element is a sum of the first sub-radiation phase slope of the antenna unit and the second sub-radiation phase slope of the corresponding feeder.

Abstract: Embodiments of this application provide a radiation apparatus and a multi-band array antenna, and relate to the field of antenna technologies. The radiation apparatus includes a radiation module, a first conductor balun, and a second conductor balun. The first conductor balun is mechanically connected to the second conductor balun under the radiation module. The radiation module includes a first radiation unit and a second radiation unit in a +45° polarization direction, and a third radiation unit and a fourth radiation unit in a ?45° polarization direction. The first conductor balun is configured to feed a first differential signal to the first radiation unit and the second radiation unit. The second conductor balun is configured to feed a second differential signal to the third radiation unit and the fourth radiation unit. The first conductor balun and the second conductor balun are disposed in the same plane.