基于同步双口SRAM的原子磁强计磁共振相位提取系统设计

针对原子磁强计磁共振激励信号相位提取过程中,数据量大、实时性强、同步要求高等特点,设计了一种基于同步双口SRAM的磁共振相位信息提取系统。首先利用FPGA控制高速同步采样AD进行数据转换;然后经同步双口SRAM实现数据的高速缓存和同步读写;最后由DSP经外部中断触发定时读取缓存的数据,并进行数字锁相处理,提取相位信息。实验结果表明:该系统对频率为35~350kHz之间的正弦信号相位提取稳定度达到0.006°,满足原子磁强计静态噪声小于20pT的应用要求。

Design of Phase Information Acquisition System for Atomic Magnetometer Magnetic Resonance SignalBased on Synchronous Dual port SARM

The phase information acquisition system based on synchronous dual-port SARM is designed to acquire the phase information of atomic magnetometer magnetic resonance signal which have large data streams to be calculated with great expectation on real-time and synchronous data sampling. Firstly, FPGA is used to control the high-speed synchronous sampling A/D converter. Then, the converted data is buffered and read or written synchronously based on dual-port SARM. Finally, DSP reads the buffered data with external interrupt and acquires the phase information based on digital phase-locked technology. The experimental results demonstrate that the stability of phase information is about 0.006° when the frequency of the input signal is between 35kHz and 350kHz, which meets the requirement of atomic magnetometer to achieve static noise less than 20pT.