Research On Design And Application Of Broadband Reconfigurable Reflectarray Antenna

With the development of microstrip antenna technology,the reconfigurable reflectarray antenna formed by applying the reconfigurable technology to the design of the microstrip reflectarray antenna can realize the functions of large-angle beam scanning and pattern reconfiguration.The array radar system requires complex phase shifters and expensive T/R components,which are difficult to promote in the field of civilian tracking and detection.This can make the reconfigurable reflectarray antenna into a large-scale array,using single pulse tracking principle,Used in the tracking and detection of targets in the civilian field.However,the reconfigurable reflectarray also has certain shortcomings.For example,the bandwidth is relatively narrow.Based on this problem,this thesis focuses on the design of a broadband reconfigurable reflectarray to ensure the realization of beam scanning while increasing the bandwidth of the reconfigurable reflectarray.This will also meet the 5G communication system's large bandwidth and high rate requirements,and contribute to the improvement of the 5G communication system.This topic uses the phase shifter in the radar phased array system as a phase shift network combined with a microstrip patch antenna.In the design of the reconfigurable reflectarray,the bandwidth and aperture efficiency of the reconfigurable reflectarray are further improved.The main work of this thesis is as follows:First of all,I discussed the research background of this subject,the research status at home and abroad,and the basic theory of microstrip reflectarrays.It briefly summarizes the development and advantages of microstrip reflectarrays as well as the working principle of reflectarrays.It analyzes the current status of communication systems.A brief overview of the current situation of the externally reconfigurable reflectarray is given,followed by a description of the micro-bandwidth reflectarray technology,and several methods to increase the bandwidth of the reflector array are mentioned.Finally,the phase quantization technology of the microstrip reconfigurable reflection array is explained,which lays the theoretical foundation for the follow-up research of this subject.Next,I introduced the design of the microstrip phase shifting network.The four phase shifters used in the radar phased array system and the digital phase shifter chip are introduced in detail,and they are designed,simulated and verified by experiments.Phase-shifting network,reflective phase-shifting network,and 3d B bridge-type phase-shifting network are the most commonly used,which solves the problem of narrow bandwidth of microstrip resonant structure,and provides clear ideas and methods for increasing the bandwidth of reconfigurable reflectarrays.Then,I introduced the design of the 1-bit broadband reconfigurable reflectarray based on the reflective phase shifting network.First,the reflective phase shifting network designed in Chapter 3 is used as the phase shifting network of the 1-bit broadband reconfigurable reflectarray.The slot-coupled double-layer microstrip patch structure has designed a 1-bit broadband reconfigurable reflectarray element.Secondly,a DC control circuit board is designed and processed to control the DC bias.Finally,the 1-bit broadband reconfigurable reflectarray element is composed of a 12 x 12 array.The focal diameter ratio and the array are optimized,and the prototype is designed and processed for beam scanning and differential beam scanning experimental verification.Finally,the application research and analysis are carried out.Finally,I introduced the design of the 2-bit broadband reconfigurable reflectarray element.First,the 2-bit broadband quadrature and hybrid phase-shifting network is designed by combining the load line phase-shifting network designed in Chapter 3 and the 3d B bridgetype phase-shifting network design,and then made further improvements to the double-layer microstrip patch antenna in Chapter 4,and designed a broadband slot-coupled antenna based on parasitic patches.Finally,the 2-bit broadband hybrid phase-shifting network and the broadband slot-coupled antenna based on the parasitic patch are combined to obtain the 2-bit broadband reconfigurable reflectarray element,and the application research and analysis are carried out.