Design of elliptical and circular aperture pencil-beam antennas using the modified lambda functions

A procedure for the synthesis of pencil-beam radiation patterns having a given null half-beamwidth and a given sidelobe level by elliptical or circular aperture antennas is presented. The given pattern is first approximated by a modified lambda function; the lambda function is then synthesized by a finite line-source current distribution, which is mapped onto the elliptical aperture. Design curves and formulas are presented.