Facebook Twitter LinkedIn
UCSD Jacobs School of Engineering

Toward Cheaper Imaging Systems for Identifying Concealed Weapons on the Human Body

San Diego, CA, June 8, 2009 --  Electrical engineers from the University of California, San Diego invented radio frequency integrated circuits that could lead to significantly less expensive imaging systems for identifying concealed weapons, for helping helicopters to land during dust storms, and for high frequency data communications. UC San Diego engineers presented this circuit at the 2009 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium on June 9, where it won one of the best three-student-paper awards.

In particular, the electrical engineers created high-performance W-Band silicon-germanium (SiGe) radio frequency integrated circuits (RFICs) for passive millimeter-wave imaging.

RFIC 2009 chip
RFIC 2009 chip from Jason May and Gabriel Rebeiz.
The new millimeter wave amplifier system works at the same frequency and follows the same underlying principles as some of the most advanced security imaging systems now in use in airports. The new UC San Diego circuit is unique in that it uses standard silicon semiconductor technology, while today’s security imaging systems working in the same millimeter frequency range often rely on expensive gallium arsenide or indium phosphide amplifiers.

This advance is from the laboratories of Gabriel Rebeiz, a professor of electrical engineering at UC San Diego’s Jacobs School of Engineering and a world leader in millimeter-wave RFIC design, phased-arrays and Micro-electro-mechanical systems (MEMS).

The IEEE RFIC Symposium is the premiere annual conference in the world for reporting recent research developments in Radio Frequency Integrated Circuits (RFICs). These circuits are responsible for the communications links in all wireless devices. This year, UC San Diego has 11 (out of 140) papers at the conference, which is more than any other university.

“Our success at this conference is a direct result of the investment that UC San Diego has made over many decades in the field of wireless communications. The RFIC field requires an interdisciplinary team, because it requires innovation in the areas of electronic devices, integrated circuit theory, electromagnetic theory and communications systems. The broad skills of the UCSD faculty have made this extraordinary level of research innovation possible,” said Larry Larson, Professor and Chair, Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering.

Jason May
Jason May, an electrical engineering PhD student at UC San Diego’s Jacobs School of Engineering and the first author on the RFIC 2009 paper
“The new circuit functions at the same frequencies as some of the most advanced millimeter wave imagers around. The big difference is that we are using a commercial silicon semiconductor process technology while other systems are typically customized and very expensive. The technologies that we use are very inexpensive and reliable, so we should be able to bring the costs of those sorts of systems down, perhaps even to handheld scanners some day,” said Jason May, an electrical engineering PhD student at UC San Diego’s Jacobs School of Engineering and the first author on the award winning RFIC 2009 paper.

Millimeter wave imaging

The new circuit includes an antenna that can be used to capture radiation in the millimeter wave frequency emitted from the human body and from objects under a person’s clothing. This radiation passes through clothing largely or completely unaffected.

Imagers operating at millimeter waves are particularly useful because they can resolve images down to a millimeter scale, fine enough detail to identify small objects and separate items on a person’s body.

“By the size of the signal we detect, we can tell the temperature of the signal we are looking at,” explained Gabriel Rebeiz, the electrical engineering professor at UC San Diego’s Jacobs School of Engineering supervising the project. “An imager with our chip could resolve images down to a millimeter scale, enabling us to identify very small objects that are on someone’s body,” said Rebiez.

“A ceramic knife concealed against a person’s leg, for instance, might appear one or half of one degree cooler than the rest of their body. We could then tell that something is there and we could exactly determine its shape,” said May.

Using signal processing, these kinds of scanners can put together a temperature map of a person’s body that includes any objects underneath the clothing.

Imagers, high speed communications systems, and other applications that operate at the millimeter wave frequency are poised to become increasingly prevalent and influential as the circuit technologies for integrating them with existing silicon technologies matures.


“High-Performance W-Band SiGe RFICs for Passive Millimeter-Wave Imaging,” by Jason May and Gabriel Rebeiz, University of California, San Diego. Presented at 2009 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, June 7-9, 2009.

This work is funded by DARPA, the Defense Advanced Research Projects Agency of the United States of America.

Below is the full list of UC San Diego papers presented at RFIC 2009

“A SAW-Less CDMA Receiver Front-End with Single-Ended LNA and Single-Balanced Mixer with 25% Duty-Cycle LO in 65nm CMOS,” by H. Khatri from UC San Diego, L. Liu, T. Chang, and P. S. Gudem from Qualcomm Inc; L. E. Larson from UC San Diego.

“A DC-102GHz Broadband Amplifier in 0.12 μm SiGe BiCMOS,” by J. Kim and J. F. Buckwalter, UC San Diego.

“Low-Loss 0.13μm CMOS 50 - 70GHz SPDT and SP4T Switches,” by Y. A. Atesal, B. Cetinoneri, G. M. Rebeiz, UC San Diego.

“A Two-Channel Ku-Band BiCMOS Digital Beam-Forming Receiver for Polarization-Agile Phased-Array Applications,” by B. Cetinoneri, Y. A. Atesal, G. M. Rebeiz, UC San Diego.

“A 25 dBm High-Efficiency Digitally-Modulated SOI CMOS Power Amplifier for Multi-Standard RF Polar Transmitters,” by S. Pornpromlikit from UC San Diego, J. Jeong from Kwangwoon Univ, C. D. Presti from UC San Diego, A. Scuder from STMicroelectronics, and P. M. Asbeck from UC San Diego.

“Fully Integrated Dual-Band Power Amplifiers with On-Chip Baluns in 65nm CMOS for an 802.11n MIMO WLAN SoC,” by A. Afsahi from UC San Diego and Broadcom Corp, A Behzad from Broadcom Corp, V. Magoon from Broadcom Corp, L. E. Larson from UC San Diego.

“Background Estimation of Power Amplifier Nonlinearities for OFDM Signals,” by
P. V. Kolinko , L. E. Larson from UC San Diego.

“High-Performance W-Band SiGe RFICs for Passive Millimeter-Wave Imaging,” by J. W. May, G. M. Rebeiz from UC San Diego.

“A 4-Channel 24-27GHz CMOS Differential Phased-Array Receiver,” by
T. Yu, G. M. Rebeiz, from UC San Diego.

“A Dual-Band CMOS CDMA Transmitter without SAW and Driver Amplifier,” by
M. Farazian from UC San Diego, B. Asuri from Qualcomm Inc, Y. Zhao from Qualcomm Inc, L. E. Larson from UC San Diego.

“Injection Locked Oscillator Arrays for Spectrμm Analysis,” by
T.D. Gathman, J.F. Buckwalter from UC San Diego.


Print News Release  Email News Release

  • Facebook
  • Twitter
  • LinkedIn

Media Contacts

Daniel Kane
Jacobs School of Engineering
Phone: 858-534-3262