Mutual synchronization of two coupled klystron oscillators

We present the results of numerical simulation of synchronization of two coupled delayed-feedback S-band klystron oscillators. A 1.5-D time-domain particle-in-cell code is used for simulation. Optimal parameters of an isolated oscillator are evaluated. We investigate the pattern of synchronization on the frequency mismatch - coupling strength parameter plane. Periodical set of zones of synchronization which separate domains of amplitude death and quasi-periodic beating regimes is observed. Synchronization of interacting oscillators allows increase of the total output power.