[Quantum-ms] [EE Seminar] 4/11: Design of Robust Frequency Generation and Modulation Circuits for Low-Voltage Mobile IoT

[Columbia EE Events]

*Please join us for EE Seminar on 4/11!*

*Date: *4/11, 2-3pm
*Location: *EE conference room
*Who: *Woogeun Rhee
*Title: *Design of Robust Frequency Generation and Modulation Circuits for
Low-Voltage Mobile IoT
<https://www.ee.columbia.edu/events/ee-seminar-design-robust-frequency-generation-and-modulation-circuits-low-voltage-mobile-iot >

*Abstract:*
As future wireless systems utilizing advanced CMOS technology demand not
only low power but also low-voltage design, robust frequency generation and
modulation have become more crucial than ever. In particular, sub-0.5V
frequency synthesis and modulation are essential for enabling battery-free
operation in mobile IoT devices, as they can be directly powered by energy
harvesters without the need for additional DC-DC converters. However,
designing a low-voltage fractional-N PLL is highly challenging, as both
matching and linearity degrade significantly when the supply voltage is
scaled down. The first part of this talk will discuss the extensive use of
a 1-bit ΔΣ modulation method to develop robust frequency modulation systems
by mitigating nonlinearity issues. Then, a low-voltage BLE transmitter
based on a bias-current-free hybrid fractional-N PLL with voltage-mode
phase detection will be presented. Lastly, other energy-efficient wideband
transceiver designs from my research group will be briefly introduced.

*Biography:*
Woogeun Rhee received the B.S. degree in electronics engineering from Seoul
National University, Seoul, Korea, in 1991, the M.S. degree in electrical
engineering from the University of California, Los Angeles, CA, USA, in
1993, and the Ph.D. degree in electrical and computer engineering from the
University of Illinois, Urbana-Champaign, IL, USA, in 2001.

>From 1997 to 2001, he was with Conexant Systems (now Skyworks), Newport
Beach, CA, USA, where he was a Principal Engineer and developed low-power,
low-cost fractional-N synthesizer products. From 2001 to 2006, he was with
IBM Thomas J. Watson Research Center, Yorktown Heights, NY, USA, and worked
on clocking area for high-speed I/O serial links. He was a Visiting
Professor at Seoul National University, Korea, from August 2022 to February
2023. He is currently a Professor with the School of Integrated Circuits,
Tsinghua University, Beijing, China. He has published more than 180 IEEE
papers and holds 24 U.S. patents. His research interests include
energy-efficient short-range radios for mobile IoT, UWB transceivers for
secure wireless connectivity, and mixed-signal circuits including
phase-locked loops.

Dr. Rhee currently serves as the Editor-in-Chief for IEEE OJ-SSCS. He has
served on the AdCom of the IEEE Solid-State Circuits Society and the BoG of
the IEEE Circuits and Systems Society, as a SSCS Representative. He was an
SSCS Chapters Steering Committee Member from 2021 to 2023, a Distinguished
Lecturer from 2016 to 2017, and an Associate Editor for OJ-SSCS, JSSC, and
TCAS-II. He has served on the TPC for IEEE conferences, including ISSCC,
CICC, and A-SSCC. He was the TPC Chair of A-SSCC 2021 and has been the
Steering Committee Member of A-SSCC. He is an IEEE Fellow.

*Faculty Host:* Mingoo Seok
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