Sidelobe level reduction in ACF of NLFM waveform

摘要

In this study, an iterative method is proposed for non-linear frequency modulation (NLFM) waveform design based on a constrained optimisation problem using Lagrangian method. To date, NLFM waveform design methods have been performed based on the stationary phase concept which has been already used by the authors in a previous work. The proposed method has been implemented for six windows of Raised-Cosine, Taylor, Chebyshev, Gaussian, Poisson, and Kaiser. The results reveal that the peak sidelobe level of autocorrelation function (ACF) reduces about an average of 5 dB in the proposed method compared with the stationary phase method, and an optimum peak sidelobe level is achieved. The minimum error of the proposed method decreases in each iteration which is demonstrated using mathematical relations and simulation. The trend decrement of minimum error guarantees convergence of the proposed method.