Design And Research Of Multi-beam Antenna Based On Spatial Beam Decomposition

Multi-beam antennas have been widely used in wireless communications and other fields due to their high gain and airspace coverage.Based on the low-orbit satellite communication system as the application background,a series of studies on multi-beam antenna has been done first.And then,a multi-beam antenna based on spatial location relationship is proposed.Firstly,according to the requirement of satellite gain coverage,the beam coverage requirements and beam switching angles of the satellite multi-beam antenna are determined by calculating gain flux coverage,and then determine the specific implementation of multi-beam antenna based on spatial beamforming.Secondly,a wide beam circularly polarized transceiver antenna is designed and realized.The antenna is in the form of microstrip antenna,and the beam width is extended by means of three-dimensional grounding structure and the extension of medium radius of the antenna substrate.A 3dB directional coupler is used as feed network to realize circular polarization and transceiver.The simulation results show that the circular polarization gain is greater than 0 dBi at 360° azimuth and±74° elevation.The antenna is fabricated and measured,and the measured results and the simulation results are consistent.It means that the proposed antenna has been achieved a wide beam,circular polarization,and transceiver sharing.Then,a high gain circularly polarized receiving antenna is designed and realized.A director is added to the orthogonal dipole antenna to increase the gain.And a 1×2 array is designed to enhance the edge gain of the beam.The antenna is fabricated and measured,and the measured results and the simulation results are consistent.Finally,according to the overall structure and the beam decomposition scheme,extracting the directional data of the two kinds of antenna to synthesize the directional pattern of the multi-beam antenna.The results show that the receive gain of the multi-beam antenna is greater than 8dBi and the transmit gain is greater than OdBi at the beam coverage edge of 360° in azimuth and±60° in elevation,which shows the designed multi-beam scheme can meet the requirements of gain coverage in both receiving and transmitting situations.