Sidelobe Reduction and Gain Characteristics of Partially Uniform Antenna Arrays

摘要

It has been found that sidelobe reduction can be effected by properly adjusting the excitation amplitudes in the outermost elements of a uniform array. The report presents a systematic method for determining these amplitudes exactly. The method can be applied to both broadside and endfire arrays, and can be used to eliminate radiation in any particular direction. By forcing a controlling factor to be a Chebyshev polynomial, a given amount of sidelobe suppression throughout the visible range can be guaranteed. Compared to Dolph-Chebyshev arrays designed for a certain range of sidelobe levels, partially uniform arrays offer higher directive gains and lower maximum-tominimum amplitude ratios as well as much simpler excitation requirements. By suitably adjusting the excitation amplitudes, it is also possible to create a null in the pattern of a partially uniform array in any specified direction. Several modified techniques are discussed and numerous illustrative examples are given. (Author)