Amplifier performance of the NRL ubitron

Operation of the Naval Research Laboratory Ku-band ubitron has successfully demonstrated a high power/efficiency and broad bandwidth. This device employs a helical wiggler/axial guide field configuration. Performance levels achieved at 16.6 GHz can be summarized as a peak power of 4.2 MW for an efficiency of 17.5% and a gain of 29 dB, and an instantaneous bandwidth of 22%. Substantial beam loss was observed. The specific loss rate was correlated with output power, and reached a level of 50% beam loss at the 4.2 MW level. Nonlinear simulations of the experiment are in good agreement with these observations.