Research On Multi-band Reconfigurable Circular Polarization Antenna For Satellite Communication Terminal

With the operation of the second generation satellite global coverage positioning system in China,the global satellite navigation and positioning systems(GNSS)have been formed,and the application of satellite digital broadcasting system is also expanding.For the international business application scenario,multi-system complementary sharing has become an inevitable trend in the development of the industry,but different systems correspond to different frequency bands and polarization methods,which put forward higher requirements for the design of satellite antenna.In view of the practical need of multi-system sharing of satellite communication terminals,three types of satellite terminal antennas are designed by using stacked technology,common aperture reconfigurable technology and Polarization Reconfigurable technology,which can provide reference for the design of multi-system common type satellite terminal antennas.The main research work is as follows:Firstly,a dual-band dual-polarized laminated antenna is designed for satellite navigation and satellite digital broadcasting system.The antenna adopts a laminated structure.The upper and lower layers carry out microstrip tangent in different directions to achieve different polarization.The perturbation is loaded on the circular aperture of the lower substrate radiation unit.The radius,position and two feed port positions of the loading circular aperture are optimized.The dual-band satellite antenna for vehicle is obtained.Then a common aperture reconfigurable circular polarization antenna is designed for GLONASS and GPS/BDS mode switching system.A new method of dual-frequency switching by loading the inter-digital structure with switching diodes on parasitic branch microstrip substrate antenna is proposed.The effectiveness of the loading method is verified by optimization design and experiment,which provides a reference for the design of switching antenna for satellite system.Finally,a multi-band polarization reconstructed satellite antenna is designed to meet the application requirements of multi-band and switchable polarization of global satellite antenna.The antenna utilizes the broadband characteristics of distorted symmetrical cross-dipole circular polarization antenna and realizes switching between left-handed circular polarization and right-handed circular polarization by loading four switching diodes.The feasibility of the design is verified by simulation.The antenna physical test shows that the antenna achieves the design target in five bands:GPS,Beidou Generation 1,Beidou Generation 2,GLONASS and Galileo.