Millimeter-wave Detection and Imaging

Devices and circuit technologies for millimeter-wave detection and imaging are being researched. This technology has applications in security screening, avionics, and medical imaging among others.

The technical approach being pursued is the use of InAs/AlSb/GaSb and Si/SiGe heterostructure backward diodes for detection, and monolithic integration of other electronic and passive components with these devices for compact imaging system applications.
These devices are based on asymmetric tunneling induced by the broken-gap alignment possible in heterostructures between InAs and GaSb, or interband tunneling in p+/n+ Si/SiGe heterostructures.
Comprehensive characterization of the devices, including DC characteristics, millimeter-wave sensitivity, nonlinear characterization, and noise measurements are key elements of this research effort.

The devices are designed and characterized in the High Speed Circuits and Devices lab, and fabricated in the Notre Dame Nanofabrication Facility. Portions of this work have been performed through collaborations with HRL Laboratories, LLC.

Recent demonstrations (selected):

• Measured cut-off frequencies > 1 THz obtained (N. Su et al., 2006 Lester Eastman Conf. on High Performance Devices)
• Temperature sensitivity characterized, physical origin determined (N. Su et al., IEEE Electron Device Lett., vol. 28, 2007; R. G. Meyers et al., IEEE Electron Device Lett., vol. 25, 2004)
• First demonstration of Si/SiGe heterojunction backward diode detector at microwave frequencies (S. Park et al., Electronics Lett., vol. 43, 2007)