Research And Design Of Airborne Conformal End-fire Phased Array

In airborne and missile-borne military radar detection systems,the antenna array used for receiving and transmitting signals often needs to achieve wide array beam coverage airspace without affecting the aerodynamic performance of the array structure.In theory,the end-fire array can meet both requirements.Compared with the broad-side array used by the traditional radar system,the maximum radiation direction of the endfire array is not the normal direction of the array plane,but the axial direction of the array element arrangement.Therefore,the aperture resources in direct proportion to the gain are not required in the direction of the maximum gain of the array,which makes it feasible to use the end-fire array to achieve blind filling in the scanned space under the limited aperture resources in the future unmanned combat.Based on the demand analysis of practical application scenarios,this thesis studies and designs some conformal low-profile end-fire scanning arrays that can be well carried on the airborne platform.The main work includes the following three parts:In the first part,a wing conformal omnidirectional end-fired phased array is designed based on the improved low-profile conical monopole.Firstly,the structure of the initial low profile element model is optimized under the excitation of the periodic boundary endfire phase of the simulation software,and the impedance matching of the array elements in different end-fire scanning directions is realized;After that,a wing conformal array model with dual-layer inverted feed array elements is designed to solve the problem of the upwarp of the end-fire beam of the traditional end-fire array,and to verify the working performance of the array after carrying the actual application platform.The array has achieved 360°omnidirectional end-fire scanning coverage in azimuth plane,and is well mounted on the aircraft platform with its low profile characteristics.The second part is to give a solution to the active VSWR deterioration of the edge element of the omnidirectional end-fire phased array.The original edge matching deterioration array element of the array is designed as a reconfigurable antenna element.The reconfigurable element includes two reconfigurable states,which are used as the endfire tail row and the first row unit respectively,to solve the matching deterioration problem in the end-fire scanning process of the array.The monopole omnidirectional endfire phased array without matched deteriorating elements is realized.In the third part,based on the improved low-profile rectangular log-periodic antenna,a broadband end-fire phased array is designed.First of all,the traditional monopole logperiodic antenna design was completed.Then,the low-profile monopole log-periodic antenna design was realized by using the monopole miniaturization technology,and stable low-profile vertical-polarized broadband terminal radiation was achieved in the 2-12 GHz frequency band.Finally,the performance of the designed antenna will be verified in specific application scenarios,and the four-element planar end-fire phased array will be designed to achieve azimuth broadband end-fire scanning,and the double-layer circular array will achieve azimuth broadband end-fire coverage through feed switching.The above contents completed the research and design of the airborne conformal end-fire phased array according to the idea of demand analysis,process design,simulation analysis,and experimental verification,and provided a solution for the blind filling design of the airborne integrated detection platform.