The concept of optimizing the field pattern of a given equally spaced array by thinning process represents a very challenging problem with considerable practical advantages.In this paper

a properly modified genetic algorithm (GA) is applied at the first time to design a low sidelobe hexagonal planar array by thinning process.A study of the frequency characteristics of the thinned hexagonal planar array is made

and a new method

which has less computational work and is especially useful for large antenna arrays

is proposed for performance improvement of antenna arrays by thinning partially the array.The results show that the performance of the hexagonal planar array could be greatly improved by thinning

the maximum relative sidelobe level was reduced by 7.5~9.4dB

and thinning partially the array could attain the same performance as that of fully thinning.