| Wireless communication systems are facing various electromagnetic interference,so in some application fields,sidelobe level has become one of the crucial indicators in antenna design.The waveguide slot array antenna has the advantages of compact structure,high aperture efficiency,large power capacity and low loss,and its amplitude distribution on the aperture plane is easy to control,and it is easy to achieve low side lobe or extremely low side lobe.Therefore,this kind of antenna has received extensive attention and research.At the same time,the trend of broadband antennas is becoming increasingly evident,and the research on broadband back cavity slot antennas has gradually become a research hotspot.The paper focuses on the design,simulation,and optimization of slot array antennas.The main work is as follows:(1)Based on the waveguide slot antenna theory and Taylor synthesis principle,a broadband low sidelobe waveguide slot array antenna using PolyStrata technology was designed,with a center frequency of 77 GHz.Extract and fit the characteristic parameter curves of radiation gaps in a simulated mutual coupling environment to obtain the gap size parameters of the array.In order to achieve low sidelobe level,Taylor amplitude distribution is used for array synthesis on the antenna feed network,and a test switching structure of GSG-micro coaxial-waveguide is designed.The frequency range of S11<-10 dB of the antenna ultimately covers 74.4 GHz-79.2 GHz,with a relative impedance bandwidth of 6.3%,and sidelobe levels on both the H and E planes are below-25 dB.Finally,a 77 GHz waveguide slot circularly polarized linear array was designed using parameter extraction methods,and a wide axial bandwidth was achieved.(2)Designed a W-band broadband low sidelobe 16 based on two-dimensional Taylor synthesis theory 16×16 cavity backed slot array antenna,designed based on PolyStrata technology.The antenna subarray of 2×2 is fed from the bottom layer and excites the resonant cavity through coupling slots.It radiates through four radiation slots on the resonant cavity,and expands the antenna bandwidth by utilizing the close resonance frequencies of the TM130+TM310 mode and TM320 mode in the resonant cavity.The output port amplitude of the fully parallel feed network adopts a two-dimensional Taylor distribution for antenna synthesis to achieve low sidelobe performance.The S11 impedance bandwidth of the antenna is less than-10 dB,reaching 17%(88.3 GHz-104.7 GHz),and the maximum sidelobe levels on both the H-plane and E-plane are below-25 dB.(3)Based on the principle of the previous cavity backed slot antenna,a K band easy to process,low-cost 8×8 cavity backed slot array antenna.The antenna is designed based on a substrate integrated cavity waveguide(ESIW)structure,consisting of 5 layers of low-cost FR4 dielectric plates.From the top layer down,it consists of a radiation gap layer,a resonant cavity layer,a coupling gap layer,a power division feed layer,and a coaxial feed layer.The test results show that the working bandwidth of the antenna’s subarray and its array with a reflection coefficient less than-10 dB is 27.6%and 23.7%,respectively.The maximum gain in the test band is 27.2 dBi,and the test results are in good agreement with the simulation results. |
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