Dimensions of two types of optimum pyramidal horns that have approximately equal beamwidths in the principal planes.  Two designs are given because the design cannot satisfy the optimum values of S in the two planes and meet a 2:1 ratio waveguide in the single plane (a physical requirement for the joint to the waveguide). Download executable RHOPTG (Linux version) to design these horns in a DOS window.

opt_horn_dim.gif