A simple method for predicting the characteristics of tape structures

A method is described for calculating the dispersion characteristics and coupling impedance of a Karp-type slow-wave structure. The structure is regarded as a ridge waveguide, periodically loaded with short-circuited stub lines. The analysis is simple and lends itself to the speedy assessment of the performance of a particular circuit. Measurements on 8 and 4 mm experimental backward-wave oscillators are described and are shown to verify the usefulness of the approximate theory. These results are also compared with those obtained by field-theory analyses.