A travelling-wave tube amplifies microwave signals by passing an electron beam down a long vacuum envelope containing a slow-wave structure, usually a wire helix. The radio frequency signal travels along the helix at roughly the same speed as the electrons, continuously extracting kinetic energy from the beam and transferring it to the RF wave. They provide high gain over a very wide bandwidth, making them essential for satellite transponders and radar transmitters.
The satellite payload relies on a travelling-wave tube amplifier to punch the downlink signal through the atmosphere.
Also heard as
- TWT
Related terms
Vacuum tube
An evacuated glass or metal envelope containing electrodes used to control electron flow.
Cavity magnetron
A high-power vacuum tube that generates microwaves using interacting electron streams and magnetic fields.
Crossatron
A cold-cathode gas-filled tube used as a high-power pulsed modulator switch.