Research On The Wideband And Wide-scan Technology Of Array Antennas

Electronic warfare is a modern high-tech military operation of vital importance to national security and people's well-being,and the strength of its power represents the level of a country's military power.Radar is one of the important components of electronic warfare system.In the background of increasingly severe electromagnetic environment,broadband multifunctional phased array system radar has become an important development direction of advanced radar.Phased array antenna as a converter between the phased array radar and the working environment,will also be along the broadband wide angle,multi-polarization and other directions of rapid development,which is the key technology to ensure the high performance of the antenna system work,but also the current research hot spots and difficult issues.Therefore,this paper focuses on the broadband wide-angle scanning array antenna.(1)A dual-polarized microstrip patch array antenna based on the back-cavity structure with dual-polarization and low-profile features is designed.The antenna uses a combination of back-cavity structure,capacitive coupling feed and vertical probe feed to extend the bandwidth,and the antenna array can scan to 45° in both E-plane and H-plane with 3d Bi gain drop and active VSWR less than 3.(2)A microstrip patch array antenna operating in X-band is designed.In the paper,some methods of spreading the antenna bandwidth are verified and combined.The design and simulation process of X-band microstrip patch array antenna is described in detail,including unit design and array design.Finally,with active VSWR less than 3,the antenna array can achieve the scanning performance of E-plane scanning to 25° and H-plane scanning to 45° in X-band.(3)A dual-polarized tightly coupled dipole array antenna is initially designed,and good impedance matching is achieved by using a tapering ribbon feed line and a tapering rectangular hole in the floor of the feed line.The use of frequency selective surface instead of the conventional dielectric matching layer makes the antenna lighter and easier to process.The performance of the antenna H-surface at low frequencies is improved by modifying the shape of the open slits in the floor.Eventually,the antenna has an average VSWR of about 3when scanned to 60° over 4.5 octave,except for a few frequency points.(4)A wideband wide-angle scanning array antenna based on Vivaldi unit is designed and simulated.Firstly,the Vivaldi single-polarized cell is designed and simulated,and the scanning blind spot is eliminated by adding metallized perforations.Then two single-polarized cells are vertically crossed to get a dual-polarized cell,and then the array antenna is designed and simulated according to the layout rules of the array,and the array antenna is designed and simulated with the help of matlab design GUI interface to simplify the design process of antenna array.Finally,some practical processing problems of the antenna are considered.The final bandwidth performance of 6 octave can be obtained for the case of active VSWR less than 2 without scanning,and 4.5 octave can be obtained for the case of active VSWR less than 3,E-plane and H-plane scanned to 60°.