基于FPGA的激光外差干涉仪反正切解调技术

针对高频声学应用中多普勒信号软件解调的局限,提出了一种基于FPGA的数字硬件信号解调方案.基于AD9467设计了高速ADC采集系统,以实现原始多普勒信号的奈奎斯特采样或带通采样;基于Xilinx Zynq-7000片上芯片系统设计数字信号处理系统,实现了 DDS合成参考信号与多普勒信号混频、低通滤波产生I&Q基带信号对...

Technology of Arctangent Demodulation of Laser Heterodyne Interferometer Based on FPGA

In order to eliminate the limitations of Doppler signal software demodulation in high-frequency acoustic applications,a digital hardware signal demodulation approach based on FPGA is proposed.It contains a high-speed ADC acquisition system based on AD9467 to implement the Nyquist sampling or band-pass sampling of the original Doppler signal.The digital signal processing system based on Xilinx Zynq-7000 SoC is designed to generate the I&Q baseband signal pair,which is obtained by mixing of DDS synthesized reference signal with Doppler signal and the following low-pass filtering.The CORDIC algorithm and phase unwrapping algorithm are used to demodulate the I&Q baseband signal pair and the real-time demodulation of Doppler signals is initially realized.Numerical simulation in the frequency range from 50kHz to 500kHz and the preliminary experimental results in the frequency range from 50kHz to 300kHz demonstrate the validation of the demodulation method and system.