AN ADAPTIVE CONTROLLER FOR PULSED MEGAWATT KLYSTRONS

The typical large-size klystron, operating in the 300-3000 MHz frequency range with a pulsed rf output in the 1-2 MW power range, is well known to be afflicted by an amplitude nonlinearity of the order of 10 dB and an AM-to-PM conversion of the order of 0.5°/dB. In certain cases, such as in multisection pulsed linac structures, it is difficult to adequately compensate for the amplitude and phase nonlinearities peculiar to each rf amplifier by use of conventional amplitude linearizers, phase equalizers, and fixed-parameter control loops. Design details are given for an adaptive controller for a pulsed rf amplifier which learns from a running sequence of rf output bursts to retain and use the information needed to abolish the control-loop transients otherwise present. Plots of klystron output pulses undergoing adaptation to their correct amplitude and phase are obtained from the system equations. © 1990.