Optimizing the radiation pattern of sparse periodic two-dimensionalarrays

摘要

A method for reducing the number of elements in a 2-D array whilenminimizing degradation of the beam forming properties is described. Thenmethod relies on selecting a different arrangement of elements when thenarray is transmitting energy and when the array is receiving energy. Thentransmit and receive aperture functions are chosen to minimize thendifference between the effective aperture of the sparse array and theneffective aperture of a desired dense array. In a companion paper [seenibid vol. 43, pp. 7-14, 1996], the design of sparse linear arrays usingnthe effective aperture method was described. Here, we extend this methodnto the design of 2-D arrays. Comparisons of the radiation patterns of andense 2-D array and sparse 2-D arrays with random and periodic elementnspacing are given. Using the effective aperture method, we show that thennumber of elements in a 64×64 2-D array can be reduced by morenthan six times, and the elements in a 128×128 array can be reducednby more than 12 times, with little effect on the beam forming propertiesnof the arrays