Cell Phones that See Through Walls?

Improvements in microchip technology and new scientific advances that let scientists tap into the terahertz range could lead to mobile phones that can be used to see through walls, wood, plastics, paper and other opaque materials.

The terahertz frequency, which falls between the microwave and infrared wavelengths on the electromagnetic spectrum, has not been accessible for consumer electronics like phones and radios. Researchers at the University of Texas at Dallas, led by electrical engineering professor Kenneth O, have designed a chip that allows a device to tap into these frequencies.

The new concept for the imaging system (left) and the lenses for the imaging system that will need to be replaced (right). (Images: UT Dallas)

With a new CMOS chip, devices could read images broadcast at the terahertz frequency without having to use new lenses.

“CMOS is affordable and can be used to make lots of chips,” O said. “The combination of CMOS and terahertz means you could put this chip and receiver on the back of a cell phone, turning it into a device carried in your pocket that can see through objects.”

Due to privacy concerns, Dr. O and his team are focused on uses in the distance range of less than four inches.

From left, Dr. Kenneth O, director of the Texas Analog Center of Excellence and a professor of electrical engineering, and team member Yeon Kim.

The applications of such a technology include authenticating documents, protecting against counterfeits, diagnosing tumors, ordinance identification and monitoring air toxicity. There are also more communications channels in the terahertz frequency than in the range currently used for wireless communication, which could make it a basis for faster communications networks.

“There are all kinds of things you could be able to do that we just haven’t yet thought about,” O said.

The researchers now intend to build an entire imaging system based on this technology.

The research was presented at the International Solid-State Circuits Conference (ISSCC) in February. Other team members include Ruonan Han, Yaming Zhang, Youngwan Kim, Dae Yeon Kim and Hisashi Sam Shichijiro.

For more information, visit: www.utdallas.edu