RADIATION FROM CONE-SHAPED FLANGED OPEN-ENDED THIN-WALL CIRCULAR WAVE-GUIDE

The performance of an open-ended circular waveguide with a very sharp cone-shaped flanged termination was measured. These measured results were found to approach those calculated for a semi-infinite open-ended circular waveguide with infinitesimal wall thickness. This analysis is based on L. A. Weinstein's (1969) theory (Wiener-Hopf solution) and sufficient accuracy was obtained to compare results with other methods. Measured results are included for a practical model of this type of antenna demonstrating the deterioration of the cross-polarization performance due to the antenna's finite wall thickness. The theoretical and experimental results have shown very good agreement except for the cross-polarization values below -32 dB predicted by theory.