Researchers from the University of Texas at Dallas and Oklahoma State University have developed an inno­vative terahertz imager microchip that can enable devices to detect and create images through obstacles that include fog, smoke, dust and snow. The team is working on a device for industrial appli­cations that require imaging up to 20 meters away. The techno­logy could also be adapted for use in cars to help drivers or autonomous vehicle systems navigate through hazardous conditions that reduce visi­bility. On an automotive display, for example, the techno­logy could show pixelated outlines and shapes of objects, such as another vehicle or pedes­trians.

“The techno­logy allows you to see in vision-impaired environments. In industrial settings, for example, devices using the microchips could help with packaging inspections for manu­facturing process control, monitoring moisture content or seeing through steam. If you are a fire­fighter, it could help you see through smoke and fire,” said Kenneth K. O, professor of electrical and computer engineering. Yukun Zhu, a doctoral candidate in electrical engi­neering, announced the imaging technology recently at the virtual Inter­national Solid-State Circuits Conference, sponsored by the Institute of Electrical and Elec­tronics Engineers and its Solid-State Circuits Society.

The microchip emits radiation beams in the terahertz range (430 GHz) of the electromagnetic spectrum from pixels no larger than a grain of sand. The beams travel through fog, dust and other obstacles that optical light cannot penetrate and bounce off objects and back to the micro­chip, where the pixels pick up the signal to create images. Without the use of external lenses, the terahertz imager includes the microchip and a reflector that increases the imaging distance and quality and reduces power consumption.

The researchers designed the imager using comple­mentary metal-oxide semi­conductor (CMOS) technology. This type of integrated circuit technology is used to manufacture the bulk of consumer electronics devices, which makes the imager affordable. O’s group was one of the first to show that CMOS techno­logy was viable, and since then they have worked to develop a variety of new appli­cations. “Another break­through result enabled through innovations that overcame funda­mental active-gain limits of CMOS is that this imaging technology consumes more than 100 times less power than the phased arrays currently being investigated for the same imaging appli­cations. This and the use of CMOS make consumer appli­cations of this technology possible,” said O.

“UT Dallas and Oklahoma State continue to discover techno­logical inno­vations that will help shape the future,” said Swami­nathan Sankaran, design director and Distin­guished Member Technical Staff at Texas Instrument Kilby Labs. “What Dr. O and his research team were able to accomplish was truly remarkable with this terahertz monostatic reflec­tion-mode imager work. Their research paves a path for improved raw angular resolution and low-power, cost system inte­gration, and we are excited to see what appli­cations and use cases this terahertz imaging techno­logy will lead to.” (Source: UT Dallas)

Reference: Y. Zhu et al.: A 430GHz CMOS Concurrent Transceiver Pixel Array for High Angular Resolution Reflection-Mode Active Imaging, IEEE Int. Solid-State Circuits Conference 2022

Link: Texas Analog Center of Excellence, University of Texas at Dallas, Richardson, USA