Demonstration of Phase-Locked Magnetron Array With Multiple Phase-Difference Distributions

This article proposes a magnetron array phase-locking circuit based on peer-to-peer (P2P) locking. The circuit is composed of cascaded coaxial lines and newly designed couplers. By adjusting the cascade topology between the coaxial lines and couplers, discrete phase-difference transitions near 0° and 180° can be achieved between adjacent magnetrons, enabling multiple phase-difference distributions in the magnetron phase-locked array, without using phase shifters or other precise phase control circuits. A phase-difference prediction method based on a theoretical model of coupling coefficients is developed and validated using a vector network analyzer (VNA) and high-power experiments. Considering that the three-magnetron array is the basic unit of large-scale arrays, this article focuses on the three-magnetron array and constructs and tests four types of phase-locking circuits under different cascade topologies. The experimental results show that at 2.466 GHz, the magnetron array achieves stable phase locking with four distinct phase-difference distributions and phase-locking efficiency up to 90%. Notably, for an array composed of N magnetrons, up to $2^{N-1}$ discrete phase-difference distributions can theoretically be achieved, demonstrating excellent phase control flexibility.