In this paper, we have analyzed and designed a digital RF receiver based on the optimization of the dynamic range parameter to secure the wideband characteristics and linearity of digital radar receivers. To improve the wideband characteristics and dynamic range, a low noise amplifier is matching design with a noise source to minimize the noise figure in 1 GHz bandwidth and we improved the linearity of RF-receiver by securing the conversion gain characteristics of receiver through the design of active mixer. RF receiver is designed to give gain 63 dB, noise figure 1.2 dB and dynamic range of RF receiver has 75.8 dB in a wide band of 8.8~9.8 GHz. It is shown to be applicable to X-band digital radar receiver.