Pyramidal horns. I. Simple expressions for directivity as a function of aperture phase error

New expressions for the gain-reduction factors of a pyramidal horn are developed. They offer fast and accurate computation of the horn directivity, in either linear of second-order form. These equations are much easier to evaluate than the exact equations, which involve complicated Fresnel integrals. The formulas are expressed in terms of gain-reduction factors, based on the quadratic phase errors in the aperture.<
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