Reflection from the aperture of a long<tex>E</tex>-plane sectoral horn

Abstract

The complex reflection coefficient of a long E -plane sectoral horn is derived using the geometrical theory of diffraction. Single diffraction alone is shown to be sufficient to describe the contribution from the E (widely separated) edges, while singly and doubly diffracted fields from the H edges are included by using an open waveguide result derived elsewhere. A relatively uncomplicated expression is obtained for the complex reflection coefficient of the horn which agrees well with experiment for horns with slant wall lengths greater than about 3\frac{1}{2} guide wavelengths.