Simulation and Experiment Study of Modular <i>X</i>-Band Phase-Locking Magnetron

Abstract

The conventional mutual coupling phase-locking technique uses waveguides to directly connect magnetrons to operate as a whole device. However, this method is not suitable for large-scale phase-locked array applications due to the considerable challenges in achieving the required vacuum level. Thus, the modular magnetron applied to the mutual coupling phase-locking technique was proposed. First, the coupling structure was designed to combine a double-ridged waveguide and a rectangular waveguide for incorporating an RF window. Therefore, a single magnetron could be vacuumed as a modular unit. Subsequently, in simulation, two modular X-band magnetrons connected by a coupling bridge were verified to operate in a phase-locked state with a 0° phase difference, with a phase-locking efficiency of 97.2%. Second, an experimental scheme capable of characterizing directly the phase difference between magnetrons was proposed. In the experiment, multiple sets of time-domain signal data were randomly sampled when the magnetrons were in a stable operating state. The experimental results were essentially consistent with the expected design phase difference of 0°, as the phase difference between the two magnetrons remained consistently between 3° and 5°, with the phase-locking efficiency measured at 91.9%.