Logo: University of Southern California

Viterbi Researchers Demonstrate a Single-Chip CMOS Radar Camera

The 49-pixel Imager fits on small area of a single chip; applications range from search and rescue to biomedical imaging

February 05, 2008 — Following up on earlier research two researchers from the USC Viterbi School of Engineering will present a chip that can detect RF signals coming from 49 distinct angles, simultaneously, over an ultra wide bandwidth.  In principle, the chip can capture images passively, by measuring the natural RF radiation energy from the objects, or in an active mode by measuring the power of reflected signals that are transmitted.

Hashemi, left and Shu. Photo by Phil Channing
Prof. Hossein Hashemi of the Viterbi School's Ming Hsieh Department of Electrical Engineering and graduate student Ta-Shun Chu designed the device they presented February 4 at the 2008 IEEE International Solid State Circuits Symposium (ISSCC) in San Francisco.

According to Hashemi, "the chip benefits from a novel architecture that allows for the integration of an entire 2D array in a small area of a standard 0.13μm CMOS chip," processed by the familiar and economical CMOS process.

Creating the device on CMOS, says Hashemi, "reduces the cost by orders of magnitude, while increasing the functionality. Low-cost digital cameras have become abundant in everyday’s life.  However, these cameras only capture a limited part of the vast information that is available in the electromagnetic spectrum; namely, the part that is visible to our eyes!  Our RF camera captures valuable information that is available at the lower frequency section of the electromagnetic spectrum.  Due to the longer wavelengths of RF waves, our RF camera can operate in poor weather conditions and in dark and can image through optically opaque objects.”

"The chip can be used in various radar and imaging system to detect, identify and locate multiple objects simultaneously in a complex environment," Hashemi continued saying that "potential applications include through-the-wall imaging, and search and rescue missions" (such as finding earthquake victims buried in rubble, and distinguishing survivors from the dead).

Other possible uses include biomedical imaging, security monitoring devices and real-time collision avoidance systems for vehicles, both safety devices for cars with drivers and applications in autonomous vehicles.
Die used to create chip; 4.1 millimeters (less than .2 inches) square

Last year the two researchers presented a CMOS chip that produced a single beam over an ultra wideband that could be scanned in one-dimension.

The new version’s 7x7 array of simultaneous beams "offers many more degrees of freedom for communication and imaging in complex environments.  For an imaging application, it reduces the image capture time by a factor of 49.”

This work was supported in part by the Boeing Phantom Works and the National Science Foundation.