Reseach On Ku/Ka Reflectarray Antenna

With the rapid development of precision guidance,wireless communication and other technologies,the traditional parabolic antenna and microstrip patch array antenna is difficult to meet the requirements of compact,low profile,lightweight and caliber multiplexing.Reflectarray is a new type of antenna that combines the advantages of reflector antenna and p microstrip patch array antenna in recent years.This dissertation focuses on the key issues that realize the compact and lightweight dual-band dual-reflectarray utilizing the above-mentioned technology.Based on the systematic summary of the previous research results,this dissertation presents and designs a new dual-band reflectarray unit with wide application prospect,and applies it to the dual-reflectarray designing of the Cassegrain system for the first time.The content of this paper can be summarized as the following aspects:1.Research on dual-band reflectarray unit.This dissertation presents a new type of unit structure composed of a double-layer cross dipole patch for Ku band,a cascading ring and a circular patch for Ka band for the first time.Their number relationship is 1: 4.The dual-band reflectarray unit has the advantage of that both bands are achieved phase shift dynamic range,low processing error sensitivity,non-polarization requirements and so on.2.Research on the mutual coupling between high and low band units.The interaction between the high and low band units can cause the erro of phase compensation for incident wave,which will affects the overall radiation performance of the dual-band reflectarray.In this paper,based on the analysis of the traditional coupling suppression method,a kind of element coupling suppression structure is proposed creatively,and a good coupling suppression effect is obtained in the Ku/Ka dual-band unit design: the maximum phase error of the dual-band reflectarray element in the Ku-band is less than15,in the Ka band phase shift error remains within.10.3.Research on compact dual-reflector antenna based on reflectarray structure.Aiming at the problem that the traditional dual-reflector antenna has large longitudinal volume and difficult to be machined,this dissertation attempts to apply the reflectarray to design the dual-reflector antenna(hereinafter referred to as the card antenna)of the Cassegrain system.The optimal design scheme of the dual-reflectarray is only 67.85% of the conventional structure.4.The experimental study on Ku/Ka band dual-reflectarray is carried out.On the basis of the above,the designed Ku/Ka band dual-reflectarray is processed and the test work is completed.The comparison between the text farfield pattern and the Sigelian antenna simulation pattern shows that the Ku/Ka dual-reflectarray can achieve the function of the Cassegrain antenna,and the radiation performance is good,for the development of compact,lightweight antenna solutions laid the theoretical basis.