Coupling Between Narrow Transverse Inductive Strips in Waveguide

A general expression is found for the susceptance of two narrow transverse strips of differing width, unsymmetrically located in a rectangular waveguide. This analysis is based on extremization of the current-density ratio between the two strips, through use of the variational principle. The resulting susceptance values have been experimentally verified, and the theory is valid for interstrip spacings ranging down to the point where the two strips touch, or even overlap.