Multiorder-Cascaded Matching of Coupling Structures for High-Efficiency Phase Locking Between Multiple Magnetrons

The scheme of a high-efficiency phase locking based on a novel multiorder cascaded coupling structure is proposed to establish a high-power 2 $\times$ 2 array consisting of four megawatt-level, S -band magnetrons. Every magnetron is designed with only one coupling port to match the cascaded coupling structure, in which a matched, cascaded, standing-wave field is built up to support the phase-locked mode with 0 phase difference between them. To obtain high-efficiency phase locking, the two-order, cascaded, standing-wave field is produced with a small portion of stored energy, which matches with four $\pi $ modes in four magnetrons. Particle-in-cell (PIC) simulation results show that a 0-phase difference between four magnetrons is obtained with every magnetron delivering a peak power of 2.4 MW, which is almost the same as the power of a free-running magnetron. The array can deliver a total power of up to 9.6 MW. The power conversion efficiency of the array is 65.2%, which is almost the same as that of the free-running magnetron. This demonstrates the high-efficiency phase locking. The scheme is promising in developing a large-scale array for higher-power microwave generation.