高分辨THz-TDS采集传输的嵌入式设计与优化

为了满足太赫兹高分辨检测及实时处理需求，利用光电导天线产生和探测太赫兹时域光谱信号，基于现场可编程门阵列(field programmable gate array, FPGA)实现太赫兹时域光谱的采集、维纳滤波反卷积处理、传输和上位机显示等功能。将采集到的太赫兹时域光谱数据进行维纳滤波反卷积处理，实现还原太赫兹信号、提高时间分辨率以及降噪的效果，将数据由以太网传输的方式传输到上位机进行实时显示，针对实际检测中太赫兹信号反卷积后脉宽较宽，提出在维纳滤波反卷积算法中引入与频率相关的函数对算法进行优化，使信号的脉宽变窄，提高检测精度。优化的维纳滤波反卷积算法处理结果相比于原始算法信噪比增加7 dB,脉宽降低0.2 ps,实现更高的检测分辨能力，算法在FPGA中实现，精度误差小于0.7%,处理效率提升14.29倍，并且减少后期上位机处理时间。

Embedded design and optimization of high-resolution THz-TDS acquisition and transmission

In order to meet the requirements of terahertz high-resolution detection and real-time processing, the photoconductive antenna is used to generate and detect terahertz time-domain spectral signals. Based on the field programmable gate array, the functions of terahertz time-domain spectrum acquisition, Wiener filtering deconvolution processing, transmission and host computer display are realized. The collected terahertz time-domain spectral data is subjected to Wiener filtering deconvolution processing to achieve the effect of restoring terahertz signals, improve time resolution and noise reduction. The data is transmitted to the host computer by Ethernet transmission for real-time display. In view of the wide pulse width after deconvolution of terahertz signals in actual detection, it is proposed to introduce a frequency-related function into the Wiener filtering deconvolution algorithm to optimize the algorithm, so that the pulse width of the signal becomes narrower and the detection accuracy is improved. Compared with the original algorithm, the signal-to-noise ratio of the optimized Wiener filter deconvolution algorithm is increased by 7 dB, the pulse width is reduced by 0.2 ps, and the higher detection resolution is realized. The algorithm is implemented in FPGA, the accuracy error is less than 0.7%, the processing efficiency is improved by 14.29 times, and the post-processing time of the host computer is reduced.