Study Of Multi-beam Antenna Based On Ridge Gap Waveguide Integration

With the rapid development of wireless communication technology,the band resources in the low frequency band are becoming saturated,and there is an urgent need to develop the spectrum resources in millimeter wave(mm Wave)as well as higher frequencies.As a new type of non-contact semi-closed waveguide structure,gap waveguide has the advantages of low loss,easy fabrication and modularity.Gap waveguide has promising application prospects in the engineering design of antenna arrays,large feeding networks,filters,and active device packaging in the frequency band above millimeter wave.Millimeter-wave multibeam antennas can use passive beam forming networks to realize beam scanning,improve the gain of antennas,and maximize the utilization of spectrum resources.Therefore,integrated multibeam antennas designed using gap waveguide technology can reduce the loss in mm-wave wireless communication.At the same time provide the valuable experience for the future design of higher band and more integrated gap waveguide antenna arrays.This thesis focuses on the Butler matrix beam forming network based on ridge gap waveguide(RGW)and Tx/Rx component integrated to ridge gap waveguide,which is mainly as follows.Firstly,the background and significance of research on multi-beam antennas integrated to ridge gap waveguide are introduced.The research progress of integration and packaging using gap waveguide and the performance of Butler matrix millimeter wave multi-beam antenna array designed using SIW line at home and abroad are analyzed and reviewed.The basic theories required for designing RGW transmission lines,RGW transition structures,and multibeam antenna arrays are introduced and analyzed to provide the theoretical foundation for the later work.Secondly,the design of a 4×4 RGW Butler matrix was completed by choosing a suitable RGW transmission line to design a broadband three-branch line 3d B coupler,a planar crossjunction,and a complementary phase shifter.The design of 5G focal band(24-28GHz)beam forming network is completed by using Butler matrix network.Then double ridged gap waveguide linear polarized end-fire antenna is designed by using the double ridged horn antenna.Combined with the designed 4×4 Butler beam forming network,this antenna array can achieve ±37° beam coverage.Considering the limitation of the linear polarized antenna,the RGW dual circularly polarized end-fire antenna is designed with the use of septum polarizer.Cascaded with the Butler matrix,a multi-beam antenna array which achieve ±30° dual circularly polarized beam coverage is designed and simulated.Finally,by designing a horizontal transition from RGW to coplanar waveguide,the integration of low noise amplifier MMIC chip to RGW is realized and the test was completed using the vertical transition from RGW to standard waveguide.The vertical transition of RGW was also designed to expand the 4×4 Butler matrix to 4×8 Butler matrix by multilayer structure.Then a RGW high gain multibeam antenna array with beam switching function was completed.The maximum gain of this multibeam antenna array under passive condition is 22.7d Bi,which is suitable for forming 5G cellular network.