Experimental Study on the Effect of the Characteristics of a Switching-Mode Power Supply on a Phase-Locked Magnetron

The effect of the characteristics of a switching-mode power supply (SMPS) on a microwave vacuum electron device (VED) is experimentally demonstrated. The phase and spectral characteristics of a phase-locked magnetron were evaluated according to the voltage fluctuation and the frequency of the driving high-voltage SMPS. The spectral linewidth of the magnetron harnessed by the phase-locking-loop (PLL) injection is extremely reduced to the level (12kHz at 60dBc) of the signal generator itself for the PLL by decreasing the voltage ripple (peak-to-peak voltage) to 6V, while the effect of the switching frequency is irrelevant to the spectral purity of the magnetron. And the stability of the phase of the signal from the magnetron shows linear dependence on the voltage ripple with the proportional coefficient of 0.011°/V.