Planar array antenna pattern nulling based on sequential quadratic programming (SQP) algorithm

In this paper we propose an efficient method based on the sequential quadratic programming (SQP) algorithm for the pattern synthesis of planar antenna arrays with prescribed pattern nulls in the interference direction and minimum slide lobe levels SLL by controlling only the phase of each array element. This method is the most widely used to solve nonlinear optimization problems. It consists of transforming the nonlinear problem to sequence of quadratic subproblems by using a quadratic approximation of the lagrangian function. In order to illustrate the performance of the proposed method, several examples of uniform excited planar array patterns with 10×10 one-half wavelength spaced isotropic elements to place the main beam in the direction of the useful signal while suppress the interfering narrow or wide band signals are performed.