Models and Properties of Slow-Wave Systems

This chapter analyzes the influence of periodical inhomogeneities and the influence of finite length on properties of slow-wave systems. Symmetrical slow-wave structures consist of two helical or meander electrodes. Increase of characteristic impedance with frequency is the important property of the twined helical system. Super-wide-band slow-wave structures are necessary to have a high operation speed of electrodynamic delay lines, traveling-wave cathode-ray tubes, and other electron devices. In a traveling-wave cathode-ray tube, the electron beam crosses the central part of the twined helical deflecting system. In order to reduce frequency distortions of signals, cathode-ray tubes with traveling-wave deflecting systems are used. One slow-wave electrode of the system acts as a signal path and the other electrode is used as a compensation voltage electrode. A traveling electromagnetic wave induces electromotive forces in the short-circuited turns of the compensation voltage helix.