Antenna, antenna assembly, and base station

Embodiments of the present disclosure provide an antenna, including a first antenna portion and a detachable second antenna portion that is connected to the first antenna portion, where the first antenna portion includes a first radome and a first reflection plate disposed in the first radome, the second antenna portion includes a second radome and a second reflection plate disposed in the second radome, and a working surface of the first reflection plate and a working surface of the second reflection plate are coplanar; and a plurality of antenna arrays on the working surface of the first reflection plate and a plurality of antenna arrays on the working surface of the second reflection plate are configured to construct different types of antennas based on a quantity of frequency bands and a quantity of transmit and receive channels that are configured for the antenna.