Research On The Fast Algorithm For Scattering And Radiation Characteristics Of Periodic Array

Periodic array structures such as array antennas,frequency selective surfaces,and metamaterials are widely used in the current military and civilian fields.For the large-scale periodic array,traditional full-wave simulation method and the commercial simulation software are limited by the computer hardware and is difficult to get its electromagnetic characteristics quickly.Infinite array analysis method based on Floquet theory,only need to analyze one unit of the array,but the lack of appropriate consideration of the impact of edge effects,and can not achieve the antenna array analysis to the requirements of flexible feeding.In this paper,the infinite array analysis method which only need to analyze one unit is used and improved,the main work is:Firstly,the surface integral equation of the perfect conductor surface is deduced in detail.The main process of the integral equation is given,including the selection of the basis function,the selection of the test function for the inner product test,the calculation of the matrix equation elements and the algorithm of solving matrix equation.Besides,the electromagnetic parameters is given for the radiation and scattering problem.In addition,for the periodic problem,the form of periodic green function and the fast calculation method are given.Secondly,three kinds of analysis methods based on infinite array are introduced and analyzed.The first is the periodic moment method,through the analysis of a unit in the array to achieve the purpose of rapid calculation of the array;the second is to solve the problem of periodic moment method that ignore the edge effects of the array,the proposed hybrid approach of method of moment and periodic moment method,the current distribution on the array intermediate unit is similar to the current distribution on the infinite array,and the edge element is analyzed by the method of moment.The third is the domain green function method,by estimating the current approximation between the units and the symmetry of the Green function transforms the analysis of the entire array into analysis and solution on each unit,reducing the number of unknowns and the computer resources.Then,the periodic moment method is used to analyze the infinite array which contains the mutual coupling between the units.The mutual coupling effect of the elements in the array is calculated by array scanning method,and the mutual coupling in the finite periodic array is approximated.So,compute the active element pattern of array elements and analysis of the entire array.Finally,in the face of large-scale array analysis of ordinary methods by computer resource constraints,the study of sub-array technology,which can be the result of small arrays extrapolated to large-scale periodic array,the size of small arrays depends on the mutual relationship between the array unit.The In this paper,array scanning method combined with sub-array technology,enabling rapid analysis of large-scale periodic array problem.