Large Planar Array Thinning Using Iterative FFT Techniques

A new approach for the synthesis of thinned periodic planar arrays featuring a minimum sidelobe level is presented. The method is based on the iterative Fourier technique to derive the array element excitations from the prescribed array factor using successive forward and backward Fourier transforms. Array thinning is accomplished by setting the amplitudes of a predetermined number of largest element excitations to unity and the others to zero during each iteration cycle. Basically it is the same method successfully applied earlier to the thinning of periodic linear arrays. The effectiveness of the iterative Fourier technique for thinning periodic planar arrays will be demonstrated for a number of large arrays (> 1500 element positions) with a circular aperture using various degree of thinning.