RESONANT CAVITY FOR ATTENUATING ELECTROMAGNETIC STANDING WAVES IN A WAVEGUIDE

摘要

A resonant cavity (12) made of a lossy material is coupled to a waveguide (6) through an iris (14). The cavity (12) can be made of stainless steel or have a coating of lossy material on an inside surface thereof. Moreover, the cavity (12) is resonant at a frequency (F1) of the undesired standing wave inside waveguide (6). The iris (14) is located at an electric field antinode (16) of the standing wave. For optimum coupling between the waveguide (6) and cavity (12), the quality factor (Qo) of the cavity (12) is made equal to the quality factor (Qe) of the iris (14) such that standing wave energy at unwanted frequency (F1) is absorbed in cavity (12). Multiple frequencies of the standing wave may be eliminated by locating identical cavities (12) at different antinodes (16) along the waveguide (6). This invention is useful with an extended interaction klystron output circuit (2) coupled by the waveguide (6) to a node convertor (8).