Gain-frequency response of a helix traveling-wave tube with T-shaped dielectric support rods in a metal envelope

Abstract

The slow-wave structure parameters of a traveling-wave tube with T-shaped dielectric rods in a metal envelope were optimized for flat-to-negative dispersion characteristics obtained by the sheath-helix model of analysis. The analytical results were validated against those obtained by the tape-helix model of analysis and CST Microwave Studio. Such optimized structure parameters also gave wideband gain–frequency response of the device as predicted by Pierce’s small-signal theory. The electron beam voltage was also identified as an additional parameter for widening the device bandwidth.

Keywords:

• Wideband TWTs
• TWT gain–frequency response
• helical slow-wave structures
• helix dispersion
• helix interaction impedance