300-GHz-band CMOS wireless transceiver and its future

300 GHz is the upper limit frequency of millimeter waves, and is also the entrance of terahertz. The use of the 300-GHz band for wireless communication is being discussed by International Telecommunication Union (ITU) and The Institute of Electrical and Electronics Engineers (IEEE) since frequencies beyond 275 GHz are unallocated. In the 300-GHz band, since atmospheric attenuation is as small as several dB/km, km-class long-distance communication is expected. Conventionally, 300-GHz-band transceivers were realized by compound semiconductors and photomixing, but we realized a transceiver by using a CMOS process. In this presentation, we introduce the features of 300-GHz-band communication, the outline of 300 GHz band CMOS wireless communication transceiver, and its future.