Abstract: For the optimization of sparse separable array,a new method based on matrix pencil method is proposed to reduce the number of elements,to solve the element locations and to design the excitations.The pattern of seperable planar array is produced by the pattern of two orthogonal linear array.Firstly,the two desired orthogonal linear array radiation pattern is sampled to form a discrete data set.Secondly, a Hankel Matrix is built and the singular value decomposition(SVD)can be performed.By discarding the insignificant singular values,we obtain an optimal lowrank approximation of the Hankel matrix which corresponds to sparse antenna array. Finally,the generalized eigen-decomposition is employed to calculate the sparse linear array locations and excitations,then the locations and excitations of the sparse separable array are obtained.Simulation results are presented to demonstrate the efficiency of the proposed approach.