A New Low-Sidelobe Pattern Synthesis Technique for Equally Spaced Linear Arrays

A class of nonuniformly excited, equally spaced linear arrays (ESLAs) that can meet design requirements for half-power beamwidth and sidelobe level (SLL) without any limitation is introduced. These arrays are constructed using the patterns of uniformly excited arrays as building blocks, thus lending themselves to simple analytical descriptions and analysis. A design procedure is presented, which can be used to determine the required number of elements and the excitation currents to achieve the specified radiation properties. For these arrays, the element currents always decrease monotonically from a maximum at the array center to a minimum value at edge elements. This property can be exploited to limit the current taper ratio (CTR) when the number of elements is very large. Simulation results indicate that these arrays can provide half-power beamwidths, directivities, and SLLs comparable to those of other desirable array choices, such as Chebyshev arrays, with the same number of elements and interelement spacings. It is shown that, in fact, when the number of elements is sufficiently large, the array introduced here outperforms the Chebyshev array by providing larger directivity and allowing a smaller CTR to be achieved. Numerical results for broadside and endfire arrays are given.