Abstract:

This talk will review a 20x10-pixel 200 GHz imager for biomedical applications implemented in 28nm CMOS technology.  Each pixel contains a 200 GHz split-ring resonator occupying an area of 46um x 54um with active Q-enhancement, electronic selection, and correlated double-sampling, all of which lead to high-sensitivity imaging.  The architecture allows a single 200GHz source, which consists of a 50GHz VCO followed by a frequency quadrupler, to drive a transmission line that couples to the rings. Through electronic selection, rings can be selectively turned on and off enabling pixel-by-pixel acquisition of the image while minimizing pixel-to-pixel interference. The frequency of the source is tuned to the resonance frequency of each pixel, where high-sensitivity measurements take place thanks to the high-quality factor of the resonators.  Flicker noise is suppressed using a correlated double-sampling approach implemented between the resonators and the baseband amplifiers. The output signal is measured using phase detection for enhanced sensitivity and better stability with temperature and drift.  The imager has been characterized, calibrated, and tested using a PDMS structure fabricated on top of the chip.  By patterning the PDSM, we can create test images and verify the functionality and the calibration of the array of pixels.  We are actively testing the functionality of the sensor with beads and biological samples.

BIO:

Ali M. Niknejad received the Ph.D. degree in electrical engineering from the University of California, Berkeley, in 2000 where he now holds the Donald O. Pederson Distinguished Professorship chair in the EECS department at UC Berkeley and he is a faculty co-director of the Berkeley Wireless Research Center (BWRC).  He is also the Associate Director of the Center for Ubiquitous Connectivity (CUbiC) and also served as the Associate Director for the Center for Converged TeraHertz Communications and Sensing (ComSenTer). Prof. Niknejad received the 2020 SIA/SRC University Research Award, recognized “for noteworthy achievements that have advanced analog, RF, and mm-wave circuit design and modeling, which serve as the foundation of 5G+ technologies.”  Prof. Niknejad is the recipient of the 2017 IEEE Transactions On Circuits And Systems Darlington Best Paper Award, the 2017 Most Frequently Cited Paper Award of the Symposium on Very Large-Scale Integration Circuits, the CICC 2015 Best Invited Paper Award, and the 2012 ASEE Frederick Emmons Terman Award.  He is also the co-recipient of the 2013 and 2010 Jack Kilby Award for Outstanding Student Paper, and the co-recipient of the Outstanding Technology Directions Paper at ISSCC 2004.  His research interests lie within the area of wireless and broadband communications and biomedical imaging and sensors, integrated circuit technology (analog, RF, mixed-signal, mm-wave), device physics and compact modeling, and applied electromagnetics.