A broad-band slow-wave structure for a millimeter traveling-wave tube amplifier

A new filter-type slow-wave structure, which is considered as an interdigital line loaded with inductance in shunt, is described in this paper. The results of the cold-test study of the structure are presented in terms of the phase velocity and impedance measurements. For the structure studied, interaction takes place between multiple electron streams and the axial electric field of the +1 space harmonic. The circuit has broad-band properties of phase and interaction impedance as a circuit for a traveling-wave amplifier. The maximum deviation of the phase velocity for a 30 per cent bandwidth has a value on the order of ±0.3 per cent. The structure is suitable for use as a high-power amplifier operating with a 20 per cent bandwidth in the millimeter-wave region.