**5. Patents**

Shan Yin, Xintong Shi, Wei Huang, Ling Guo, Fangrong Hu, Wentao Zhang, Xianming Xiong. A transmission-type terahertz two-bit encoding device and system. 2019210801324 (China).

**Author Contributions:** Conceptualization, S.Y.; investigation and data curation, X.S.; writing—original draft preparation, S.Y., X.S. and W.H.; writing—review and editing, W.H. and W.Z.; funding acquisition, S.Y., W.H., W.Z., F.H. and Z.Q.; project administration, X.X.

**Funding:** This research was funded by the National Science and Technology Major Project of China (No. 2017ZX02101007-003); the National Natural Science Foundation of China (Nos. 61565004, 61665001 and 61965005); the Natural Science Foundation of Guangxi Province (Nos. 2017GXNSFBA198116 and 2018GXNSFAA281163); the Science and Technology Program of Guangxi Province (No. 2018AD19058); and the Open Project of Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Big Data Processing (No. 2017CSOBDP0203). Wei Huang acknowledges the funding from Guangxi Oversea 100 Talent Project and Wentao Zhang acknowledges the funding from Guangxi Distinguished Expert Project.

**Conflicts of Interest:** The authors declare no conflict of interest.
