Research On Key Technology Of Satellite Communication Phased Array Antenna

The satellite communication phased array antenna has the advantages of wide coverage,high information transmission rate,and fast beam scanning,which is one of the important research topics of countless antenna workers.The two characteristics of dual circular polarization and wide-band wide-angle scanning of satellite communication phased array antennas are the most difficult parts for scholars to design and research,and the scientific research is of great significance.Therefore,the analysis and research in this paper mainly focus on the design of the dual circularly polarized feed network,the design of the dual circularly polarized phased array antenna,and the wide bandwidth angle scanning of the phased array antenna.The main work contents are summarized as follows:(1)Research on the dual circularly polarized feed network of satellite communication antennas.In order to meet the demands of miniaturization of the feeder network and to solve the insufficient power capacity of the network,two different schemes are designed.First,a three-branch line directional coupler based on microstrip line is designed to meet the requirement of miniaturization of antenna feed network in satellite communication system.The coupler has the advantages of low cost and easy processing,and can be used in various communication equipments in medium and low frequency bands that do not require power capacity.Second,a new type of directional coupler is designed by applying more advanced micro-coaxial technology,which finally solves the problem of insufficient power capacity of the feeding network.Compared with the traditional microstrip line coupler,the coupler can realize dual circularly polarized feeding,and at the same time,it has the advantages of lower loss and larger power capacity.Through design and simulation,it is concluded that it has good performance indicators,which has important reference significance for the application of satellite communication antennas in complex environments.(2)In view of the low profile and dual circular polarization requirements of phased array antennas in the field of satellite communications,the Ku-band dual circular polarization phased array antennas are studied.First,a dual circularly polarized antenna array based on the microstrip form is designed using a multi-layer PCB board,and an exploratory choice is made to use a low dielectric constant medium between the multi-layer parasitic patches instead of the traditional air or foam medium filling.After adjusting and matching through open stubs,the antenna performance is good,the structure is more stable and the profile is lower.Subsequently,a stripline directional coupler with an improved feed network was used to achieve the purpose of dual circularly polarized feeding,and finally an 8 × 8 array of dual circularly polarized radiation that could scan the beam within a range of ±45° was formed.The consistency between the actual measurement and the simulation is good,and it can meet the requirements of the dual circularly polarized phased array antenna for satellite communication.(3)Research on wide-bandwidth angle phased array antenna,design a tightly coupled phased array antenna that can cover the common frequency band(12～18GHz)of satellite communication,and can satisfy both broadband and large-angle scanning of satellite communication phased array antenna.demand.The actual measurement and simulation results are in good agreement.When working in the linear polarization mode in the 12～18GHz frequency band,it can achieve an angle scan of ±60°;when working in the circular polarization mode,it can achieve an angle scan of ±30°.