A 500 watt CW, PPM, X-band TWT for ECM and communications application

The design and performance of a PPM focused TWT which has produced over 500 watts of CW power across the octave frequency band from 5.2 to 10.4 GHz is presented. This performance represents an advance of about 3 dB in the state-of-the-art microwave power generation in octave bandwidth TWT´s. A helix interaction circuit is used to obtain bandwidth operation. This, together with the rugged mechanical design of the TWT, make it suited for use in Airborne ECM equipment. It is focused with an axially magnetized integral pole piece PPM focusing using Alnico 8 magnets. The configuration of the focusing structure has been modified from the conventional in order to facilitate removal of heat from the helix. Cooling of the TWT can be accomplished with either forced air, circulated liquid, or conduction to the mounting plate.