An X-band forward wave DC operated crossed-field amplifier

An X-band, dc operated, forward wave, crossed-field amplifier has been developed utilizing a helix coupled vane structure as the slow wave circuit. The amplifier, designed for phased array applications, is contained in a 6-inch diameter magnetically shielded package 10.5 inches long, weighing 26.5 pounds. This tube uses an emitting sole and a debunched reentrant electron stream. Debunching is accomplished in a drift space located between input and output waveguide matching sections. THe tube is operated from a dc power supply. Cathode current flow is initiated by the RF input signal and is turned off at the end of the RF drive pulse by the application of a short voltage pulse to a turn off electrode.