Synthesis of unequally spaced linear antenna arrays
In antenna synthesis an approximate analytical model is chosen to represent, either exactly or approximately, the desired radiation pattern and then the model is realized by an antenna model. This process is most conveniently achieved by antenna arrays. For antenna array consisting of identical elements, the major factors that determine its radiation characteristics are the inter-element spacing, the elements' excitation amplitudes and phases. Commonly, antenna array synthesis is carried by making the inter-element spacing constant and only varying either the excitation amplitude and or phase.
In this paper, antenna synthesis is achieved by varying all the array parameters-inter-element spacing, excitation amplitudes and excitation phases. The results show that the method is more efficient in synthesis accuracy and minimization of sidelobes. Also the method needs fewer number of array elements to synthesize an array exhibiting the same (or better) level of directivity and sidelobe level in comparison with uniform arrays. Reduction in number of array elements has a positive consequence in manufacturing cost effective arrays.