An approach of thinning planar phased array antenna by using finite difference method

For a planar array, as the size increases, the total number of elements increases rapidly. Thinning the planar array antenna is of interest for lowering the power requirement, reducing the cost and decreasing the mutual coupling effects. The problem is to get the same or slightly different array pattern with the reduced number of antenna elements. When the boundary conditions of an electromagnetic problem are known, the field inside the defined boundary can be reconstructed. This fact is utilized in array design: the elements on the sides of the array are used to define the boundary conditions and the fields inside, i.e., the fields to be received by the inside elements, are computed. In this way, in order to recover the original pattern, the finite difference (FD) method is used to substitute the removed elements virtually. The main criteria for this operation are the sufficient information on the boundary conditions and the time required to solve the defined problem. These aspects, together with application results, are presented.