Research On High Precision Phase Center Antenna Based On Beidou Satellite Navigation System

With the the improvement of requirements and the enrichment of application scenarios,the high-precision satellite navigation system has been further studied and developed,and has gradually become one of the important bases for the development of many fields.As the terminal antenna of the high-precision satellite navigation system,the stability of the phase center of the high-precision phase center antenna will significantly affect the positioning accuracy and working performance of the system.Therefore,it is of great significance to study the reasons affecting the phase distribution of the far field and take effective measures to improve the stability of phase center.Firstly,this paper briefly summarizes the research status and the design difficulties of high-precision phase center antenna and introduces the concept of antenna phase center.Then,this paper analyzes the characteristics of antenna phase distribution in the far field by the method of theoretical derivation and numerical calculation,and deepens the understandings of related concepts and evaluation methods about antenna phase center by adopting the thinking of from part to whole and a approach of statistics.Next,this paper takes the microstrip antenna as an example,which is the main antenna form of the terminal antenna of the high-precision satellite navigation system,studies the influence of the mode of feeding,conductor grounding plate structure and other factors on antenna polarization performance and phase distribution in the radiation of far field,and summarizes the relevant conclusions and rules.And then,a new design scheme about the high-precision phase center antenna is proposed,which can modify the antenna phase distribution in the far field and improve the stability of antenna phase center.Finally,based on air-coupled microstrip antenna,which works in the B3 frequency band of Beidou satellite navigation system,the design scheme is verified by simulation and measurement.And the results of simulation and test show that this design scheme is effective and feasible.This paper is comprised of the followings:First,the development and research status of high precision satellite navigation system and its terminal antenna are reviewed,the concepts and evaluation methods of antenna phase center are introduced,and the realization forms,the main research directions and difficulties of high precision phase center antenna are summarized.Second,according to the antenna phase center analysis model,the phase distribution of the antenna in the far field is analyzed by means of theoretical analysis and numerical calculation,and the relative concepts of phase center and phase center stability of antenna are further understood combined with the idea of from the part to the whole and the analysis method of statistics.Third,based on multi-point uniform feeding technology which can realize circular polarization radiation,this paper briefly introduces its working principle and realization mode,simulates and analyzes the effects of different feeding modes on the far-field radiation performance of microstrip antenna.Furthermore,the relationship between the circular polarization performance and the phase center stability is established and summarized.Fourth,based on the effect of the structure of the conductor ground plate of the microstrip antenna on the phase distribution and phase center stability of the antenna in the far field,and the design of the high-precision phase center antenna,a new design scheme for modifying the phase distribution and improving phase center stability of the antenna is presented,which is also verified by the simulation of an air coupled microstrip antenna.Then the parameters of the structure of the conductor ground plate is analyzed.Fifth,a high precision phase center antenna and its feed network are designed and fabricated,which works in the B3 frequency band of Beidou satellite navigation system,the results of simulation and measurement show the effectiveness and feasibility of the design scheme,which provide a design scheme and an effective measure to improve the stability of antena phase center in the process of high precision phase center antenna design.Sixth,the work and main content of this paper are summarized,and the research direction is put forward.