Radiation Pattern of an Open-Ended Transmission Line with Impedance Boundaries

Abstract

Using the approximate solutions of the dispersion equation and the equation for the relation between the longitudinal components of electric and magnetic fields of an asymmetric hybrid waves of lowest orders the aperture distributions and radiation patterns are calculated, the analytical expressions for the frequencies corresponding to the minimum cross polarization are obtained. The radiation from the open-ended transmission line with impedance boundaries which support the lowest off-axis hybrid mode <i>HE</i>₁₁ is shown characterized by the axial-beam symmetry and the cross polarization level which allow using the line as a feed for the single-mirror and lens antennas.