Abstract: When the spaceborne synthetic aperture radar emits pulses, the current of the power supply bus fluctuates with the frequency and pulse width of the emitted pulses, and the peak values of the current fluctuation vary greatly under different frequencies and pulse width conditions. When the frequency of the radar emitting pulse is close to the resonance frequency of the power supply system input terminal, the bus current will increase because of the resonance, and the amplitude of the resonance fluctuation will greatly exceed the peak current under the normal condition, which will have adverse effects on the satellite power supply system. Aiming at the phenomenon of bus current resonance fluctuation, the principle of current resonance fluctuation is analyzed in this paper, and a suppression method of voltage and current dual control loops is proposed. On the basis of voltage regulation control, the proposed method suppresses the amplitude of current resonance in the power supply bus by stabilizing the control of current amplitude, achieving the effect of minimizing the fluctuation of power supply bus current under any operating conditions. Through simulation and experimental verification, it is shown that the proposed method can effectively reduce the amplitude of bus current resonance fluctuation and can be used in spaceborne radar antenna systems.