Design And Research Of Wideband Frequency Diverse Array Antenna

Phased-array can electronically control the beam to achieve automatic spatial scanning,but they cannot produce the beam related to the distance,which is limited in some applications.As a result of its unique far-field characteristics,Frequency Diversity Array(FDA)radar has been a hot topic of study by scholars both at home and abroad.Because of the far-field beam dependence the angle-distance,the FDA has good anti-jamming ability and target positioning performance.At present,the research on FDA radar mainly focuses on beam formation and target parameter estimation of receiver,but there is a lack of literature on the design and implementation of FDA antenna.Therefore,this thesis focuses on the design and implementation of FDA antenna.The main work includes the following three parts:(1)The basic characteristics of FDA are studied and several realization structures of FDA are proposed.Based on the analysis of the basic model of FDA,the relationship between the periodicity,the resolution and the gate lobe suppression and the array parameters is studied.At the same time,three kinds of realization methods of FDA are proposed.Through comparative analysis,it is found that the realization structure of linear modulated frequency controlled array has good performance,which lays a theoretical foundation for the design of broadband FDA antenna.(2)The design and implementation of wideband FDA antenna are discussed.The traditional FDA produces range-angle dependent beam by using frequency increment,but the frequency increment error will seriously affect the estimation performance.In this thesis,a method based on the instantaneous characteristics of Linear Frequency Modulated Continuous Wave(LFMCW)and time delay line is proposed for the realization of FDA.A broadband frequency-controlled array antenna at C band(4.5GHz ~ 5.5 GHz)is studied and designed.By theoretical analysis and experimental measurement results,it is verified that,a Linear Frequency Modulated Continuous Wave-Frequency Diverse Array(LFMCW-FDA),has both range correlation and automatic scanning beam pattern characteristics,which is of great significance in some specific radar and communication applications.(3)The beamforming of planar FDA is discussed.The uniform linear FDA produces “S” beam which is related to range-angle,but there are some problems such as parameter aggregation fuzzy and beam direction pattern defocusing.In this thesis,the basic mathematical model of planar FDA is put forward,and the beamforming of matrix FDA and multi-carrier linear FDA is studied emphatically.