Terahertz Imaging Pixel

Japanese Journal of Applied Physics publishes a paper "Wideband terahertz imaging pixel with a small on-chip antenna in 180 nm CMOS" by Yuri Kanazawa, Sayuri Yokoyama, Shota Hiramatsu, Eiichi Sano, Takahiro Ikegami, Yuma Takida, Prasoon Ambalathankandy, Hiroaki Minamide, and Masayuki Ikebe from Hokkaido University, Sony, and RIKEN. The new paper appears to be a further development of their previous paper presented at ISW 2017.

"We propose a Si-CMOS terahertz image sensor to resolve paucity of low-cost and small-size detectors. The imaging pixel consists of an on-chip antenna and an amplifier acting as envelope detector. The pixel uses a microstrip patch antenna for receiving THz waves. However, the antenna's narrow bandwidth and large ground plane size causes major problems. A low-resistivity Si substrate degrades the gain of planar antennas besides the microstrip patch antenna. We introduce an on-chip folded-slot antenna to reduce the pixel size and prevent gain degradation due to the Si substrate. The antenna has a broader bandwidth and higher gain than conventional on-chip slot antenna. We fabricated the patch/folded-slot types of the pixel circuits by using 0.18 μm CMOS process. Measurement results show that the folded-slot antenna has a broader bandwidth from 850 GHz to 1.05 THz."

Venturebeat: In an unrelated news, FCC has started issuing 10-year licenses to experiment in 95GHz to 3THz spectrum range for the companies that are trying to find "the next big thing."