TWT amplifiers use vacuum tube technology to amplify RF and microwave signals to either strengthen a weak signal or simulate a signal’s effect on a device. Traveling Wave Tube (TWT) amplifiers, also called TWTAs, are known for their reliability and long lifetimes. TWT amplifiers are preferable over solid state power amplifiers (SSPAs) in some applications due to their capacity to generate a higher output power for a given frequency than a solid state amplifier would. TWT amplifiers are used for broadband applications like radar, satellite communications and broadcasting.
TWT technology consists of a linear-beam vacuum tube used to amplify an RF signal by absorbing the power of a beam of electrons sent through the tube. A travelling wave tube itself is a cylindrical structure with an integrated electron gun from a cathode tube. The gun focuses an electron beam at the velocity of light, which is guided to focus by a magnetic field. A helix serves as a slow wave structure, retarding propagation at the velocity of light.
Traveling wave tubes make for high-gain, low-noise and wide-bandwidth RF amplifiers. TWT amplifiers can be divided into two rough categories: broadband and narrowband. Broadband TWT amplifiers generate an output power of up to 2.5 kW. With a narrowband TWT amplifier, it is possible to utilize coupled cavity TWTs, which deliver power levels up to 15 kW.