OPTIMIZING THE RADIATION-PATTERN OF SPARSE PERIODIC 2-DIMENSIONAL ARRAYS

A method for reducing the number of elements in a 2-D array while mini mizing degradation of the beam forming properties is described. The me thod relies on selecting a different arrangement of elements when the array is transmitting energy and when the array is receiving energy. T he transmit and receive aperture functions are chosen to minimize the difference between the effective aperture of the sparse array and the effective aperture of a desired dense array. In a companion paper [1], the design of sparse linear arrays using the effective aperture metho d was described. Here, we extend this method to the design of 2-D arra ys. Comparisons of the radiation patterns of a dense 2-D array and spa rse 2-D arrays with random and periodic element spacing are given. Usi ng the effective aperture method, we show that the number of elements in a 64 x 64 2-D array can be reduced by more than six times, and the elements in a 128 x 128 array can be reduced by more than 12 times, wi th little effect on the beam forming properties of the arrays.