Research And Design Of Low Sidelobe Waveguide Slot Array Antenna

The waveguide slot array antenna is mainly composed of a series of slots in various forms on the metal wall of the waveguide.Its radiation unit can be integrated with the feed path,so it is relatively easy to adjust the specific size and etching position of the antenna radiation slots.Waveguide slot antenna is light in weight,compact in structure,and has high aperture efficiency,easy to achieve low sidelobe and ultra-low sidelobe performance,so it is widely used in the field of airborne radar,fire control radar and communication system.In this paper,rectangular waveguide,ridge waveguide and substrate integrated waveguide(SIW)are used to design and study the waveguide slot array antenna with low side lobe.The main contents are as follows:(1)Design three low-sidelobe slotted traveling-wave array antennas working in Xband.The slot admittance characteristic curve was extracted from the reference model.The slot admittance value was calculated based on the Taylor synthesis theory.The slot admittance parameters were obtained by interpolation,and cross polarization was suppressed.In order to realize the miniaturization of antenna,a waveguide form of single ridge waveguide is proposed.According to the ridge waveguide theory and the calculation method of cut-off wavelength,a low sidelobe single ridge waveguide slot array antenna is designed to ensure the characteristics of low sidelobe,realize the miniaturization of array and increase the antenna bandwidth.A low sidelobe dual-polarized waveguide slot array antenna is designed.The simulation results show that the antenna can ensure the same performance indexes such as sidelobe,gain,beam direction and beam width under two polarization modes.Therefore,the antenna has the ability of beam scanning in a small range.(2)Design two low-sidelobe SIW waveguide slot standing wave array antennas working in the Ka band.According to the equivalent theory of SIW and rectangular waveguide,the specific size of SIW was determined.Based on the steps of standing wave array design and the coupled waveguide,low sidelobe SIW slot array antenna has been designed.In order to increase bandwidth and gain,a method of sparse processing and composite metasurface is proposed.The simulation results show that the antenna bandwidth is increased by 600 MHz,the gain is increased by 1d Bi and the sidelobe are reduced by 2d B,which simplifies the antenna design and reduces the process requirements.Finally,the proposed antenna array is fabricated and measured.The simulated results satisfactorily validate the measured results.This paper mainly studies and designs five kinds of antennas,including traveling wave array and standing wave array.Each waveguide slot array antenna achieves the performance indexes of low sidelobe level,narrow beamwidth and high gain,which can be used in X band and Ka band communication system radar.