Electromagnetic-wave propagation in a conducting waveguide loaded with a tape helix

The helix waveguide is one of the slow-wave structures which has been used frequently in a wide-band microwave amplification. Previous studies have been concentrated on the slow-wave dispersion properties. An improvement of the theory of the helix waveguide modes, including the fast wave, appears urgent, because a number of newly developed microwave devices frequently utilize coupling of the electron-beam mode with the fast wave. The present investigation is concerned with the development of a theory of the dispersion properties of the EM-wave propagation in a tape-helix-loaded waveguide. The current investigation extends the theory developed by Uhm and Choe (1982) for an idealized sheath helix, to a more realistic tape helix.