Modified Chebyshev arrays

Abstract

A class of linear arrays is introduced which, like Chebyshev arrays, have equal sidelobes in their radiation patterns. These arrays, compared to the conventional Chebyshev arrays with the same number of elements, the same size, and the same sidelobe level, provide higher directivities when the number of elements exceeds a minimum value for specified sidelobe level and element spacing. It is established that, for an arbitrary sidelobe level, the proposed arrays always provide higher saturation directivities. These arrays are synthesised using the zeros of conventional Chebyshev arrays repeatedly, and are referred to as modified Chebyshev arrays. Radiation characteristics of the proposed arrays are investigated. The influence of element spacing on the directivity difference between conventional and modified Chebyshev arrays is studied. Variations of directivity and half-power beamwidth against number of elements are examined and compared with those of conventional Chebyshev arrays.