射频接收机对磁共振成像（MRI）质量至关重要. 本文针对接收机对模数转换器（ADC）高采样率需求导致功耗高、硬件复杂的痛点，提出了一种基于高位宽、低采样率的信号接收方案. 该方案通过提升量化动态范围来降低对采样速率的依赖，显著降低系统功耗；在数字信号处理层面，降低采样率为数控振荡器和滤波器设计提供了更高的灵活性，允许以更低阶数和更少的硬件资源实现优异的下变频和滤波性能. 基于射频直接带通采样理论，本文设计了一款应用于0.5 T MRI的低功耗低采样率接收机. 实验结果表明，该设计在提升信号动态范围和保证磁共振信号质量的同时，实现了功耗、硬件复杂度和系统成本的显著降低.

Radio frequency receivers are critical to the quality of magnetic resonance imaging (MRI). To address the key challenge in receiver design—namely, that the high sampling rate required for analog-to-digital converters (ADC) leads to high power consumption and hardware complexity—this paper proposes a signal reception scheme based on high bit width and low sampling rate. By enhancing the quantization dynamic range, this approach reduces the reliance on high sampling rates, thereby significantly lowering system power consumption. At the digital signal processing level, the lower sampling rate offers greater flexibility for filter design, enabling excellent filtering performance with lower-order filters and reduced hardware resource requirements. Guided by the RF direct bandpass sampling theory, a low-power and low-sampling-rate receiver for 0.5 T MRI systems was designed in this study. Experimental results show that the proposed design improves signal dynamic range while ensuring MRI signal quality, and simultaneously achieves significant reductions in power consumption, hardware complexity, and system cost.