A Developmental Medium-Power Traveling-Wave Tube for Relay Service in the 2,000-Megacycle Region

This paper describes an experimental 2,000-megacycle traveling-wave power amplifier designed for operation at electrode voltages below 700 volts. This tube is capable of delivering a power output of 7.6 w at a gain of 20 db and a power output of 3 w at a gain of 28 db at the optimum operating point. Maximum power outputs from 4 to 7.6 w at gains ranging from 17 to 21 db have been measured over a bandwidth of 650 mc (1,700 to 2,350 mc). Electronic efficiencies of 20 per cent and collector efficiencies close to 30 per cent have been obtained with this amplifier. Results obtained with the tube operating as a frequency shifter are discussed. A design including a permanent magnet for electron-beam focusing has been developed.