Sharpening of -plane radiation patterns of -plane sectoral horns by metallic grills

Results of an exhaustive experimental study of the effect of conducting grills on the -plane radiation patterns of -plane sectoral horns are presented. It is observed that the grills satisfying certain optimum conditions are capable of focusing the patterns with considerable improvement in beamwidth and directive gain. The impedance conditions are also improved by the presence of the grills. Data for a number of horns operating at a wide range of frequencies are presented.