本文提出了一种对仪器信道输入中的被测信号及其镜频干扰信号进行直接采样,然后采用数字混频、滤波、移相处理,进行镜频对消的抑制技术,信道可以获得高Q值、锐截止特性的镜频抑制能力,并且可避免信号幅相失真。在相关仪器中应用此技术,可以降低高频级滤波难度,简化系统构成。本文依此设计了一种实验方案并给出了仿真结果 In this paper, a method of direct sampling of the measured signal and its image interference signal in the channel input of the instrument is proposed, and then the digital frequency mixing, filtering and phase shifting processing are used to suppress the image frequency cancellation. The channel can obtain high Q Value, sharp cut-off characteristics of the image rejection, and to avoid signal amplitude and phase distortion. Applying this technology to related instruments can reduce the difficulty of high-frequency filtering and simplify the system structure. In this paper, an experimental scheme is designed and the simulation results are given