Protection of medium-power pulse klystrons

With the implementation of high-PRF (pulse repetition frequency) ground-based radar systems, there is a requirement for coherent amplifiers with low phase-noise, high average-power, and considerable flexibility in transmitted waveforms. Medium power pulse klystrons are one means of satisfying such requirements; they are available with average powers in excess of 6 kW, are tunable over 10% bandwidths, operate through Ka-band, and are typically gridded. The authors first review the protection required for overall tube survival. The particular area of grid protection is then addressed with consideration of both transient and steady state heating limits. Crowbaring and arc protection considerations, including measurement of arc discharge energy, are then discussed. Finally, the performance of one such tube in a fielded system is presented