About Us

RF Design Concepts is centrally located in the Denver, Colorado metropolitan area, ideally situated to serve clients across the United States and worldwide.

David Choi, Ph.D.

David Choi, Ph.D.

David Choi, Ph.D. is the Founder and Principal Engineer of RF Design Concepts, Ltd. an Expert Witness (Intellectual Property matters) and custom RF and power management design and consulting company and served as an Adjunct Professor (2013-2016) at the University of Colorado, Boulder.

Dr. Choi brings over a decade and a half of experience in academic research, industrial product development, technical and strategic management, as well as in intellectual property and has a diverse and vertically integrated technical knowledge base spanning (semiconductor) physics, electronic circuits and systems, and communications systems/signal processing. Dr. Choi is a subject matter expert in the area of RF circuits and systems, in particular, highly linear and efficient RF transmitters, RF power amplifier modules, novel transmitter architectures and high efficiency power supply units.

Dr. Choi was previously Technical Director, responsible for Mercury Systems $2.5M RF Power Amplifier Division. In March 2013, Dr. Choi was appointed to the Adjunct Faculty of the University of Colorado, Boulder as a member of the Research Faculty. Dr. Choi was Technical Manager of Advanced Development at Aethercomm, a manufacturer of solid state RF power amplifiers for commercial, space and military applications. As Section Manager at Samsung Corporate Technology Strategy Office, Dr. Choi was responsible for developing strategies to exploit new, frontier technologies such as hybrid nano-electronics, TeraHertz imaging, and bio-electronics.

From 2004 to 2008, Dr. Choi served as a Visiting Scholar with Professor Peter M. Asbeck’s Research Group at University of California’s Electrical and Computer Engineering Department in conjunction with the Center for Wireless Communications and Cal IT2. He collaborated with researchers on cellular and non cellular wireless transmitter technologies.

Between 2001 to 2006, Dr. Choi was a Senior Research Engineer at Nokia Research Center in San Diego, California where his areas of responsibility included (OFDM) RF systems, advanced (3G/4G) cellular transmitter architectures, new technology sourcing, and university relations.

Dr. Choi earned his Ph.D. from the Department of Electrical and Computer Engineering at the University of California, Santa Barbara and a B.S. in physics from the University of California, Berkeley. Dr. Choi has authored and co-authored IEEE journal articles and presented IEEE conference papers in high efficiency (Switched mode/Class E) RF power amplifiers, linear and efficient (UMTS outphasing) RF transmitters, and tunable impedance matching networks.

Bio & Literature:

Linked in profile: www.linkedin.com/in/dkchoi

“A Physically Based Analytic Model of FET Class E Power Amplifiers Designing for Maximum PAE,” IEEE MTT Trans, September, 1999.:
FET_ClassE_Model
“Finite DC Feed Inductors in Class E Power Amplifiers — A Simplified Approach,” IEEE MTT-S Digest, TH2D-5, Seattle, WA, June, 2002.
ClassE_Finite_DCFeed
“The Effect of Transistor Feedback Capacitance in Class-E Power Amplifiers,”
IEEE Trans. on Circuits and Systems I, December, 2003.
ClassE_FB_Cap
“Antenna Impedance Mis-match Measurement and Correction for CDMA Transceivers,” IEEE MTT-S Digest, June, 2005.
Antenna_Impedance
“A 2:14-GHz Chireix Outphasing Transmitter,” IEEE MTT Trans, June, 2005.:
Chireix_Outphasing
“CMOS Outphasing Class-D Amplifier With Chireix Combiner,” IEEE Microwave and Wireless Components Letters, August, 2007.
CMOS_ClassD

Ph.D. thesis, University of California, Santa Barbara: DChoi_PhD_Dissertation