Research On Beamforming And Multi-beam Antennas

The beamforming technology of array antenna is widely used in communication,radar,navigation and terrain,weather detection and other fields.The array antenna with low sidelobe shaping has strong anti-interference ability,which can effectively shield the interference of other clutter signals except the main beam,effectively improve the signal-tonoise ratio of the system,and at the same time avoid the ability to be detected and the electromagnetic compatibility performance.etc.have also improved.Combined with practical applications,this paper designs three antennas with the low sidelobe beamforming and multi-beam antenna technology of array antennas as the research goals.The main research contents of this paper are as follows:The first part is the research and design of low sidelobe circularly polarized array antenna.Firstly,the Taylor synthesis method is used to complete the calculation of low sidelobe weighting,and the coupling energy between microstrip lines is used to solve the feeding problem of small-scale arrays with high power division ratio,and the design of the microstrip feeding network is completed;The symmetrical oscillator is printed,and the antenna element is fed by an ultra-wideband phase-shift network to radiate circularly polarized waves;then a low-sidelobe circularly polarized six-element linear array antenna is formed.The second part is the research and design of low-sidelobe dual-polarized array antenna.Similarly,the Taylor synthesis method is used to complete the calculation of the low side lobe weight,and the target low side lobe value used in the calculation is higher than the design index,so as to offset the adverse effects on the low side lobe characteristics during the design process of the feeder network;use the coupling between transmission lines The design of part of the power splitting port is carried out in the way of energy to solve the design problem of high power splitting ratio power splitting port;at the same time,the microstrip coplanar waveguide structure and the square coaxial structure are used to eliminate unnecessary coupling between transmission lines and complete the two feeding networks.The design and miniaturization of 4×16 low-sidelobe dual-polarized array antenna are obtained.The third part is the research and design of the multi-beam antenna based on the substrate into the waveguide.First,the design of the 3d B directional coupler,-45° phase shifter and cross junction of the substrate integrated waveguide structure is completed to form a 4×4Butler matrix;the antenna array adopts four 1×4 microstrip series feed arrays,and the Adjust the width of the microstrip patch so that the radiated power of each microstrip conforms to the power distribution ratio obtained by the low sidelobe synthesis;finally,the low sidelobe beamforming on the elevation plane is completed,and a four-beam array antenna is designed.