Research And Design Of Millimeter Wave Circular Aperture And Low Sidelobe Array Antenna

In this paper,the design examples of three different types of antennas are given in view of the circular aperture application and the low sidelobe characteristics of airborne and missile-borne radar antennas.Firstly,the circular-aperture monopulse microstrip antenna array is introduced and the physical verification is completed.Then the waveguide slot antenna and GWG array antenna are discussed.The main work is:1.Design of low sidelobe microstrip monopulse antenna array:By taking the corner-fed square patch as the basic unit,a transmitting antenna and a receiving antenna by using circular square-grid arrays are designed in this paper.Based on the waveguide coupled electric bridge,a Ka-band sum and difference network of waveguide type is designed.The antenna is fed by a waveguide-coaxial conversion of the orthogonal structure.In this paper,the specific design process and method are given.The antenna is designed and fabricated,and the measurement results are consistent with the simulation.2.Design of single-ridge waveguide slot antenna:In this part,we use single-ridge waveguide longitudinal slot as the radiation units.Based on the different mutual coupling in the different position of the array,we use the EM simulation software to set up different simulation models to extract the parameter of slots.In the design we also use the method that to diffusion the long linear array into short ones,so that to weak the long-line effect.According to the energy distribution of the array,a feeding net made by single-ridge waveguide is also proposed in this paper.3.Design of GWG slot antenna:This section introduces a novel structure of the GWG unit cells,which is entitled the grounded printed cone unit cell.Due to the thinner substrate,it is possible to place two rows of EBG cells between two arrays to ensure a lower coupling.Longitudinal slots are made in the upper metal plate as radiating slots and a GWG slot antenna array is designed.This kind of structure combines the advantages of easy processing and low loss,and has wide application in Ka band or even higher frequency band.