Study of the Influence of Power Supply Ripple on Magnetron’s Output Spectrum

Magnetron is an important microwave device because of its advantages of high power, small size, lightweight, and low cost. However, due to the instability of magnetron spectrum, it is difficult to use magnetron when we need high-stability spectrum. In order to improve the output spectrum of the magnetron, many efforts have been made and we find that the ripple of magnetron power supply has a great influence on the spectrum. So this article studies this influence systematically. First, we start from the equivalent circuit of magnetron, from which we can derive the equation of high-voltage power supply ripple and magnetron's time-domain output. Then we obtain the relationship between power supply ripple and magnetron's frequency-domain output spectrum by fast Fourier transform. Through theoretical derivation, numerical simulation analysis and experiment, we find that with the increase of ripple, the spectrum is gradually disordered, noise frequency point appears, center frequency point remains unchanged, and output energy reduces. The research results of this article provide theoretical guidance for the realization of high-stability spectrum magnetron.