Abstract: In radar systems, the receive front-end function is responsible for amplifying the weak echo signals received, ensuring that the signals can be effectively processed by subsequent circuits. The noise figure is a critical metric for evaluating the degree of noise introduced by an amplifier or system. The level of the noise figure directly affects the fidelity of the signal and the sensitivity of the system. This paper is based on the design of a receive front-end with an integrated DC/DC power supply, analyzing the impact of power supply ripple on its noise figure. Finally, by optimizing the power supply design, power supply ripple was effectively suppressed, improving the noise figure of the receive front-end and significantly enhancing the purity of the signal and the overall performance of the radar systems.