Phase noise reduction in a gyroklystron amplifier

Abstract A fast feedback loop is employed to reduce conventional phase fluctuation in a klystron and a gyroklystron using both proportional and proportional-integral type feedback circuits. Phase fluctuation of less than one degree is achieved in both the klystron and gyroklystron by using a proportional type feedback circuit; in the klystron, 1.8 degrees of phase jitter is reduced to 0.8 degrees and in the gryroklystron 1.9 degrees to 0.9 degrees. These results agree well with theory. A superior phase jitter reduction ratio of approximately 0.3 is demonstrated in both the klystron and gyroklystron by adding an integrating circuit.