![]() | Only 14 pages are availabe for public view |
Abstract Waile there are well developed methods available for the optimum design of linear uniformly spaced arrays, no adequate theory exists for designing optimally directional linear arrays wi th no sidelo bes using nonuniformly spaced elements. In the present thesis, a new treatment for synthesizing linear arrays (with nonuniform spacings and uniform excitation8: to apprn::;~imat e cln s ely the compl et ely suppressed-sid elo b es-linea:r array (uniformly spaced and nonuniformly excited), is carefully discussed and analysed. The best fit allover .the visible space is achieved by using the method of Least Sq,uares. This design iE’ optimum in the sense that the location of the antenna elements is such that the radiation field pattern has the smallest sidelobe level (or nearly no sidelobes), and at the same time avoids the use of the . excitation amplt<;,’.de tapering which result s in a comp- lication of the feed syscou, add to this the large current ratios when large binomial arrays are considered. Abbreviated formulae. for two different methods which are useful in designing a suppre•¬ssed sidelo bea linear array with nonuniformly spaced and unif()rrn. ly excited elements, are deduced. A special case, when all the designed array elements are equispaced and uniformly excited, is also discussed and 8 general relation is formulated. An extension to nonuniformly spaced nonuniformly excited arrays, required to fit the binomial pattern with less number of elements is also given. Xhree exarn- pIes, one on each ()f these sections are consid€red and proved to give the best fit • |