Research On Dual Circularly Polarized Flat Array Antenna

The flat panel antenna has the characteristics of low profile and low cost.It is widely used in mobile communication,satellite communication and other fields.Modern communication systems are becoming more compact,which has promoted the research and development of dual polarization technology.Dual polarized antennas save cost and space,and have strong application value.Among them,dual circularly polarized flat panel antennas have practical application significance in satellite communication fields with tight spectrum resources.This thesis focuses on dual circularly polarized flat-panel array antennas.The main contents of the paper are as follows:(1)Introduce the development and research trends of the flat panel antenna,compare the choice of the substrate integrated waveguide slot antenna and the radial line slot antenna for dual circular polarization technology research,then elaborate the theory of dual polarization antenna to lay the foundation for the design.(2)Designed and implemented a 8×8 dual circularly polarized substrate integrated waveguide slot array antenna.First,the design flow of the dual circularly polarized antenna array element is detailed;Secondly,the design process of uniform linear array and non-uniform linear array is summarized,and two linear arrays are designed according to the process;Thirdly,a non-uniform linear array was selected for area array layout and decoupling analysis.Finally,a dual circularly polarized gap area array was fabricated and tested.The measured results show that at 12 GHz,the left and right circular polarization gain of the antenna is greater than 22.5dB and the axial ratio is less than 3dB,which verifies the feasibility of the design.(3)An improved dual circularly polarized radial antenna is designed The traditional double-layer dual circularly polarized radial line slot antenna is analyzed,and a feeding structure based on a substrate integrated waveguide is redesigned for the feeding defects of the traditional structure to reduce the antenna profile.Finally,the overall antenna design is performed.The simulation results show that the reflection coefficient of the left and right circular polarization of the dual circularly polarized antenna is less than-15 dB and the axial ratio is less than 2dB.