Experimental results of phase locking two virtual cathode oscillators

Abstract

Experiments have been completed on electrostatic and electromagnetic phase locking of two independent virtual cathode oscillators (VCO). The experiments were accomplished by using the Gemini electron beam accelerator. The Gemini accelerator was used to generate each VCO with a chosen time separation. The phase locking was observed by beating microwave signals generated in each anode-cathode gap and noting the time intervals during which the phase difference remained constant. The phase locking was observed during both electrostatic and electromagnetic coupling of the microwave power between the VCOs. We did find that one must prefill the coupling cavity with microwave power to enable one VCO to phase lock the other.