Numerical solution for the near-field transmission between two H-plane sectoral electromagnetic horns

The effect of higher order interactions in the coupling between two -plane sectoral electromagnetic horns on the field distribution at the aperture of the transmitting horn is calculated using the point matching technique. A nonsingular integral equation for the induced current in the receiving horn, due to the initially incident wave from the transmitting horn, is formulated using a conformal transformation which maps the cross sectional contour of the receiving horn onto two circles on which the induced currents are finite. The solution leads to a modified field distribution in the transmitting aperture which is then employed in Hu\´s near-zone power transmission formula to compute a gain correction factor for -plane sectoral horns. It is shown that the correction factor oscillates about that reported by Chu and Semplak with an amplitude which increases for smaller separation distances.