A novel method for analyzing sidelobe structure of nonuniform sparse linear array

Sparse linear array provides a larger aperture with a given number of elements. However, it samples the incident signal nonuniformly, so its peak side lobes can´t be obtained by traditional FFT method. An analysis of side lobe structure of nonuniform sparse linear array based on lattice theory is presented. First, the array manifold lattice is modeled. Then the relationship between nearest lattice points and the peak side lobes is investigated. Thus the problem of getting the side lobe peaks becomes the problem of finding the nearest lattice points from the origin in array manifold lattice. Based on the above theory, an algorithm for finding the number and wavenumber vector with respect to peak side lobe whose gain is higher than the given gain is proposed. Computer simulation results are presented to show its effectiveness and accuracy.