Research On The 2D Wide-Angle Scanning Phased Array Antenna Based On Pattern-Reconfigurable Technique And The Circuit

The antenna,as an indispensable part of the communication system,can realize the conversion of the free space electromagnetic wave and the guided wave on the transmission line.Because of the flexible control of the beam and the well capability of anti-interference,the phased array has quickly become the hotspot since it was proposed at the beginning of the last century.When the traditional microstrip phased array scan its main-beam to beyond ± 50 °,the index will deteriorate sharply,which leads to restrictions of the phased array's application in both military and civilian fields.So the“wide-angle scanning phased array” was proposed in the sixties of the 20 th century and has developed rapidly in the past two decades.At present,the research on the wide-angle scanning phased array in the one-dimensional dimension has made great progress,but the research of the two-dimensional wide-angle scanning phased array still remains at the preliminary stage.Based on the pattern-reconfigurable technique and the Yagi-Uda antenna principle,this thesis studies the two-dimensional wide-angle scanning phased array.The main contents are as follows.The first chapter firstly elaborates the research background and significance of this thesis,then expounds the research status of the wide-angle scanning phased array and the two-dimensional wide-angle scanning phased array based on a large number of papers material,and finally arranges the subsequent chapters.The second chapter presents the cornerstone of this article which is the relevant theoretical knowledge.The theory of microwave switch,the theory of Uda-Yagi antenna,pattern-reconfigurable technique and the theory of phased array are introduced in turn.This chapter provides the theoretical basis for all the research content of this article.The third chapter firstly proposes a new method to realize pattern-reconfiguration based on the electromagnetic boundary conditions,and designs a pattern-reconfigurable antenna by the method.Then,based on the principle of Yagi-Uda antenna,a windmill-shaped antenna unit with four-space pattern-reconfigurable technique was designed and a two-dimensional wide-angle scanning phased array antenna with triangular grid arrangement was proposed based on the unit.The phased array based on the windmill-shaped unit can scanning its main-beam up to 62° and supports a 3-dB scanning coverage up to 73.5° in each quadrants.Finally the antenna unit and array are fabricated and measured with the designed microwave switch control circuit.And the array with the control circuit is measured.The fourth proposed a improved two-dimensional eight space quadrants pattern-reconfigurable wide-angle scanning phased array based on the unit above.The goal of two-dimensional wide-angle scanning phased array is scanning the upper space of the array,so as to achieve beam coverage of the space.Therefore,an two-dimensional eight-space wide-angle scanning phased array is proposed.The array can steer its main-beam in eight different space quadrants of 0°,45°,90°,135°,180°,225°,270°,ulteriorly realize the coverage of the upper space.The electromagnetic simulation results show that the main-beam of the array can scan up to the low elevation angle in eight subspaces,and the 3-dB beam can cover up to 70°.The fifth chapter summarizes the above work of this thesis,then puts forward to the problem to be solved and the forward study contents.