Space tapaering of linear and planar arrays

The recent activity in electronically scanned arrays has stimulated interest in means of reducing both the quantities of elements required for a given size aperture and the number of different types of transmitters which would be necessary in an array using an illumination taper. One method of doing this is presented in this paper. The conventional amplitude tapered array is simulated by varying the spacing of equally excited elements, hence the name "space tapering." Space tapered arrays with predictable gains, beamwidths, and sidelobe levels can readily be designed using graphical techniques and simple mathematics. Reduction in the number of elements of from 50 to 90 per cent for moderate and large size planar arrays are possible while retaining good pattern characteristics. Although only linear and circular planar arrays are discussed, the technique can be applied to other planar and three dimensional arrays.