Can be divided into transmitter antenna and receiver antenna, etc .; can be divided into communication antennas, transmitting antennas, TV antennas, radar antennas, etc .; can be divided into ultra-long-wave antenna, long-wave antenna, medium-wave antenna, short-wave antenna, ultra-short-wave antenna, microwave According to the structure and working principle, it can be divided into line antenna, surface antenna, etc. According to the instructions, the mobile communication base station antenna can be divided into omnidirectional antenna and directional antenna. Directivity reflects the ability of an antenna to transmit or receive electromagnetic waves in a particular direction. Antenna direction is achieved by adding a reflector or oscillator inside the antenna