Grating lobe suppression with a thinned multiplicative receiving array

The multiplicative receiving array uses two arrays. The first is a conventional array with elements uniformly spaced at # /spl equiv/ /spl lambda//2. Immediately beside it, the second thinned array has elements with spacing of one half the total size of the first array. The product pattern is such that the grating lobes of the second array pattern are suppressed by the nulls of the first array's pattern. It equals the power pattern of a conventional filled array with uniform element weighting but with fewer elements in the multiplicative array - a thinned array.