Research On Passive Components Of Phased Array Feed Network

Recently,phased array radars are frequently used in various flight applications.Thesizes and weights of the phased arrays need to satisfy some rigorous demands.Sominiaturization of feed network of the phased array is one of the research trends.Besides,the technologies of radiation and anti-radiation,disturbance andanti-disturbance develop rapidly in modem electrical wars.And the environments of thewars become worse.So the phased array should have the abilities in anti-disturbanceand survival.And conformation,miniaturization,wide band,dual band and harmonicsuppression are the research trends of feed network.In this dissertation,miniaturized,wide-band,dual-band,harmonic-suppression passive components of phased array feednetwork are researched.In Chapter 1,the research background and recent developments about phased arrayfeed network are reviewed.In Chapter 2,firstly,various miniaturization techniques are summarized.Secondly,periodic slow-wave structures are analyzed,and the influences of different number ofunit cells are researched.Lastly,compact power dividers with a novel periodicslow-wave structures and capacitor loading are researched.The proposed power dividerwith capacitor loading is simple and can be easily designed.Further more,it has goodharmonic suppression performance.In Chapter 3,firstly,a numerical model of Schiffrnan phase shifter and a coarsemodel used in constructing a knowledge based neural network are established.Secondly,an accurate model of transmission line based composite right/left handed transmissionline is established.Lastly,three types of differential phase shifters using compositeright/left handed transmission line are presented,and a third type phase shifter isfabricated and measured.In Chapter 4,firstly,a dual band branch line coupler is designed.Secondly,slow-wave structure branch line couplers are researched.Lastly,novel compact branchline coupler and rat-race coupler with shared capacitor loading are designed,and the couplers can suppress harmonics.As compared with the conventional compact coupler,the proposed couplers are simple and can be easily designed.In Chapter 5,a conventional and a wide-band microstrip Butler matrix aredesigned.The wide-band Butler matrix uses a coupled microstrip to implement thewide-band differential phase shift.As compared with the conventional wide-band Butlermatrix,the proposed wide-band Butler matrix is simple and the bandwidth is wider.In Chapter 6,a summary of the whole dissertation is given,and future researchtopics are suggested.