Research On Multi Antenna Decoupling Technology Based On Beidou System

With the development of the system towards miniaturization and integration,the distance between antenna elements becomes closer,and the coupling degree also increases.The existence of mutual coupling will deteriorate the overall performance of the system.Therefore,the research on how to make multiple antenna elements still have good isolation in limited space naturally becomes the current research goal,and has important research value and significance.In this paper,the B3 band antenna unit of Beidou satellite navigation system is taken as the practical application,and the coupling effect of multiple antennas working on the same miniaturized platform due to close distance is taken as the key research content.It proposes how to solve the influence of the closer distance and stronger coupling between antenna units caused by the miniaturization and integration of the platform,and at the same time to ensure the demand for the satellite antenna with circular polarization performance,the decoupling structure will not affect the original circular polarization performance and radiation characteristics of the antenna.Specifically,the decoupling research is carried out for the B3 band antenna application of Beidou satellite navigation system,and the following work is done on the antenna unit design and array decoupling technology.Taking the B3 band antenna unit of Beidou satellite navigation system as the practical application,a small circularly polarized microstrip antenna unit is designed.Based on the above antenna unit design,the antenna elements are arrayed,and a decoupling method of dual fed microstrip antenna array based on coupling cancellation line structure is proposed.The decoupling structure is simple and occupies small space.Under the premise of ensuring the antenna center spacing of 0.36 ?,the S(2,1)can be increased from-15 d B ?-14 d B to-23 d B?-30 d B,the decoupling performance is improved by 8?16d B.It has good circular polarization performance and radiation characteristics.Based on the above antenna unit design,the antenna elements are arrayed,and a dual fed microstrip antenna array decoupling method based on interdigital structure is proposed,and the decoupling structure of interdigital line is analyzed and verified from the perspective of filter.Under the premise that the antenna unit spacing is 0.36?,the S(2,1)can be increased from-15 d B ?-14 d B to-19 d B ?-17 d B.The results show that the decoupling performance is improved by 3?4d B.It has good circular polarization performance and radiation characteristics.Based on the above antenna unit design,the antenna elements are arrayed,and a decoupling method of dual fed microstrip antenna array based on coupling line structure and interdigital lines structure is proposed.Under the premise of ensuring the antenna unit spacing of 0.36 ?,the S(2,1)can be increased from-15 d B ?-14 d B to-29 d B ?-30 d B,the decoupling performance is improved by 14?16d B.It has good circular polarization performance and radiation characteristics.In addition,in order to verify the scalability of the proposed decoupling structure,the three element linear array and the four element array are simulated at the same time,and the physical test of the three element linear array is made.The simulation and actual measurement results verify the correctness of the two decoupling structures,and have good engineering application value.