Research And Design Of Planar Antenna Based On Waveguide Slot

Planar slotted waveguide array antennas have attracted much attention due to their high structural strength,low mental loss,high aperture utilization,easy integration,and have been widely used in radar and communication fields.At the same time,because of its stable and excellent electrical performance,and easy control of aperture distribution,it becomes the preferred antenna form in application scenarios such as low sidelobes and shaped beams.In this thesis,the research and design of the waveguide broadside longitudinal slot planar array antenna are mainly carried out.The main contents are as follows:1.The development history and current situation of slotted waveguide array antennas are introduced,and the basic electrical parameters of the antenna are analyzed.Based on the basic theory of slotted waveguide antennas and array antennas,the classification and analysis methods of slotted waveguide antennas are studied.So are the synthesis methods of array antenna.2.The slot parameters are optimized with the help of the antenna aperture by extracting the near-field amplitude and phase and compensating the equivalent admittance.A planar pencil beam slotted array antenna with low sidelobe characteristics is developed.The electromagnetic simulation software HFSS is used to complete the extraction of gap parameters,and Matlab is used to complete the data processing.Taking the form of centersymmetric inclined slot coupling feed,the actual measurement results show that the antenna meets the technical requirements,the side lobe level of the E plane of the pattern is lower than-25 d B,and the side lobe level of the H plane is lower than-28 d B.3.The related theories of monopulse antenna and sum-difference feed network are studied and researched,and a planar slotted waveguide array antenna working in the Ku frequency band is simulated and designed.The waveguide magic T is selected as the basic unit of the monopulse antenna.Low sidelobe,sum-difference beam design is realized and the measured results meet the expected index requirements.The sidelobe level of the E-plane of the sum beam is lower than-20 d B,the sidelobe level of the H-plane is lower than-25 d B,the zerodepth of the difference beam E-plane is lower than-30 d B,and the zero-depth of the H-plane is lower than-30 d B.4.Based on the superposition principle and the Taylor synthesis method,a design method for the H-plane shaped beam of a wide-side longitudinal slot waveguide slot antenna is proposed.According to the flat-top beam design method,the simulation results show that the sidelobe level is lower than-20.9d B,and the half-power beamwidth is 46.8°,the amplitude fluctuation in the main radiation area is less than 0.65 d B.The problems of low front-to-back ratio and pattern asymmetry are analyzed,and the design results meet the technical requirements.