Design of circular apertures for narrow beamwidth and sidelobes with arbitrary specifications

A computer algorithm is developed to determine the required aperture distribution for a circular aperture pattern of arbitrary sidelobe specification, based on a modification of the Ishimaru and Held (1960) method. In the method, the coefficients of the Bessel series expansion of the aperture distribution are determined, following which the sidelobe peak positions are determined, and a number of iterations are performed until the desired pattern is achieved. The synthesis method is illustrated for a pattern with uniform sidelobes similar to the Taylor pattern, and patterns with sidelobes of arbitary specification. The system has application to the patterns of shaped dual reflectors, and to the design of a two-dimensional array.