Phase-Locked All-Cavity-Extraction Relativistic Magnetrons With Azimuth-Uniform Coupling Structure for Coherent Combining Applications

An investigation on the phase locking of S-band relativistic magnetrons with an all-cavity-extraction (ACE-RM) structure is carried out. In order not to disrupt the periodic distribution of electric fields in the resonant cavities, an azimuth-uniform coupling structure is introduced, which could achieve a transmission efficiency of over 98% at the operating frequency, with an amplitude difference of only ±3.3%. Furthermore, particle-in-cell (PIC) simulations demonstrate that when five ACE RMs are interconnected through four such coupling structures, phase locking can be achieved, and the relative phase jitters are controlled within ±1%. After establishing stable <inline-formula> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula>-mode oscillation in RMs, in each of the 20 ports, an average output power of over 400 MW can be obtained, corresponding to a total power of 8.5 GW and a power conversion efficiency of 45%.