A technique for controlling the radiation from dielectric rod waveguides

This paper describes a technique for controlling the radiation from a dielectric rod waveguide by placing obstacles or antenna elements at appropriate points along the waveguide. The mode on a dielectric rod was used to excite concentric rings and radial wires. The coupling of the obstacles to the mode was determined by constructing an image line with a slotted section for impedance measurements. This information was used to design several antenna arrays with different types of patterns. The measured patterns were very satisfactory.