The studies of HPM frequency-lock technique of VCO

A metal resonant cavity was used successfully to lock the high power microwave (HPM) frequency from a virtual cathode oscillation (VCO). The effects of the electron beam space charge and the energy extract slots on the cavity eigenfrequenices were calculated. On the bases of theoretical analyses and analogue tests, a length-adjustable small D/L ratio cavity and an annular intense electron beam VCO system were designed and pretty good results of VCO HPM frequency locking was obtained. The main frequency was stabilized at 4.12 GHz with 3 db bandwidth /spl les/1%, even the electron beam current changed by 12.5%.