Abstract: Unlike the phased-array beam pattern with only angular correlation,the beam pattern of frequency diverse array (FDA) is a function on time,angle and distance.This feature provides a great application value in suppressing distance-related interference and other aspects,but the inherent distance-angle coupling of the beam pattern will bring about new frequency diverse array beam control problems.How to eliminate the distance-angle coupling relationship is the premise to achieve accurate beam control and precise target positioning.To solve this problem,an SD-LCMV (steepest descent linear constrained minimum variance) algorithm was proposed based on variable load constraints to compute the optimal weight vector.At the same time,the logarithm,trigonometric function,exponential function and reciprocal four nonlinear frequency offset increment methods were introduced into ULA-FDA array to verify the decoupling performance of the ULA-FDA array transmit patterns with four different nonlinear frequency offsets.Afterwards,the MUSIC (multiple signal classification) algorithm was used to simulate the MUSIC spectrum function under different frequency offset conditions,and the performance of the target distance-angle two-dimensional joint estimation under the four frequency offset increment methods was compared and analyzed.In addition,simulation was carried out to analyze the receiver structure pattern of the sin-FDA array and the three receive signal processing mechanisms of the sin-FDA transceiver conformal array.Results show the validity of the nonlinear frequency deviation FDA array structure.