Traveling-wave tube (TWT) is a specialized vacuum tube used
in satellite systems to amplify or
generate microwave signals. Here you find some pictures of a CPI VTU-6397C3 type.
In the Klystron, a negatively charged cathode emits a beam of high-speed, high-energy electrons that travel through the cylindrical tube in straight lines to a positively charged anode. The surrounding magnet provides a magnetic field along the axis of the tube to focus the electrons into a tight beam. A coil is wound around the tube.
That’s the
helix, that provides a low-impedance transmission line for the RF energy within the tube.
When the coil is energized with a radio-frequency ( RF ) signal, then accelerates an electron beam along the axis of the tube and some of the energy from the electrons is imparted to the signal in the coil. The result is amplification of the signal.
