Multi-beam antenna system

The invention discloses a multi-beam antenna which is composed of an E-plane 4 * 4 Butler matrix end and an antenna array end, and the Butler matrix end is composed of a gap waveguide transmission line formed by arranging a 3dB coupler, a 45-degree phase shifter, a cross junction and a 0-degree phase shifter through an electromagnetic band gap structure according to a period. Compared with a microstrip line and a substrate integrated waveguide, the transmission line has the advantage of low insertion loss in a high frequency band, a 3dB coupler adopts a branch waveguide coupler, an antenna unit in an antenna array end adopts a slow-wave horn antenna, and the antenna changes a propagation constant of electromagnetic waves in a horn by adding a metal block into an H-surface empty horn, so that the purpose of changing the phase velocity is achieved, and the phase velocity of the antenna is changed. Therefore, the phase distribution of the electric field at the horn aperture is more uniform, and the amplitude dis