The increase of output microwave power of a vircator by means of external weak single-frequency signal influence

We have provided an analytical, numerical and experimental investigation of the output power of a virtual cathode oscillator under the external harmonic weak signal influence. We have shown both theoretically and experimentally that increasing the external action leads to output power growth of a non-autonomous vircator (see Fig. 1). The results of theoretical analysis are in a good agreement with the results of the experimental study. We have also analyzed physical processes in the electron beam with virtual cathode by means of consideration of spacetime diagrams of the electron beam in the vircator interaction space and the charge density distributions along the length of the vircator. It has been shown that increase of output power of the vircator is connected with increasing the bunched current in a virtual cathode region. Such conclusion has been confirmed by analysis of a steady-state model of the interaction of a pre-modulated electron beam with the electric braking field of the virtual cathode.