中文摘要：

当太赫兹波源频率发生漂移时，由于干涉效应会影响太赫兹波对样品透射测量结果的精度。设计了一种频率漂移不敏感的双光路透射测量系统。用MATLAB建立了F-P干涉效应仿真模型，对参数进行了优化，分析比较了太赫兹波源频率漂移对单路和双路透射测量系统测量精度的影响。结果表明，该测量系统有效地克服了太赫兹辐射源频率漂移对测量的影响，提高了测量精度。

英文摘要：

The precision of the conventional terahertz transmission measurement system with a parallel-plate sample will be reduced due to the interference effect, when the frequency of the THz source drifts. To resolve the problem, a frequency-drift insensitive transmission measurement system composed of double-path is proposed. A F-P interference model is built with MATLAB. The parameters are optimized, and the effects of the terahertz source frequency drift on the precision of both the single-and double-path transmission measurement are analyzed and compared. The results demonstrated that such kind of measurement system could avoid the influence of the frequence-drift of the THz source, thus improving the measurement accuracy.