关键词: 磁共振成像, 射频接收机, 低功耗

Abstract:

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.

Key words: MRI, radio frequency receivers, low power consumption