The Cassini mission Ka-band TWT

A 10-watt, 32 GHz TWT is being developed and space-qualified for delivery to the Jet Propulsion Laboratory (JPL) for incorporation into the Ka-Band Transmitter Package for the Cassini Mission. The TWT program is a collaboration between NASA Lewis Research Center (LeRC), Hughes Electron Dynamics Division, and JPL. The Cassini Mission is planned for launch to the environment of Saturn in 1997. Designated Hughes 955H, the TWT has demonstrated an overall saturated efficiency in excess of 40 percent. To achieve this performance, several LeRC-developed technologies, including computer-aided advanced designs of the helix and the multistage depressed collector (MDC), along with suppression of secondary electron emission from the MDC electrodes, were used in the TWT design. An engineering model TWT and two flight model TWT´s have been fabricated, packaged, and performance-tested for delivery to JPL. The production of flight hardware as a part of a program which originally was intended as a research effort has resulted in reduced overall costs and a shortened delivery schedule. This development demonstrates the value of vacuum electron devices in low-power microwave applications, frequently conceded to solid state devices in system planning.<>