在太赫兹频段，损耗对折叠波导慢波结构的特性有显著影响。提出一种计算折叠波导慢波结构损耗的理论模型，推导出弯曲波导的衰减系数。分别使用理论模型和商业仿真软件计算了0.67 THz折叠波导慢波结构的损耗，二者的计算结果吻合较好，表明理论模型有较高的精确度。最后，使用理论模型分析了0.67 THz折叠波导慢波结构的结构参数变化对损耗特性的影响。

Attenuation has significant influence on folded waveguide slow-wave circuit in the terahertz range. A theoretical model calculating the loss of folded waveguide slow-wave circuit is presented, and the attenuation coefficient of the bend waveguide is derived in this paper. The loss of 0.67 THz folded waveguide slow-wave circuit is evaluated by the proposed theoretical model and commercial simulation software respectively, the results of the two methods show perfectly accordant, which indicates the theoretical model has great precision. In the final, the influence of the variation of structure parameters on the loss of 0.67 THz folded waveguide slow-wave circuit is studied by the theoretical model.