Dispersion-Shaping in a Helix Slow Wave Structure Using Metal Fins

Abstract

A simple, straightforward equivalent circuit analysis for a helix supported by dielectric wedge bars in a finned metal shell, a slow-wave structure that is used in high power, broad-band TWT's, shows that there exists an optimum value of the radial fin dimension corresponding to a fairly dispersion-free phase velocity versus frequency response of the structure.

Indexing Terms:

• Dispersion Shaping
• Equivalent Circuit Analysis
• Slow-Wave Structure
• Travelling-Wave Tubes