- RF power amplifiers and transmitters; RF Circuits and Systems for cellular, wireless.
- Power electronics (Power management).
- Analog circuits.
- Semiconductor devices.
- Electrical and electronic engineering.
RF Power Amplifier Design
- Architectures: High power output stages, full TX chain, and integrated RF front end.
- Form factors: Pallet (open and shielded), module (fully enclosed).
- Up to 20GHz. and 3kW.
- Bandwidths: Decade or greater.
- Modes of operation: Class A, Class AB/B, Class C, Class D, Class E, and Class F.
- RF Device technologies: LDMOS, GaN HEMT, GaAs FET/HEMT/pHEMT/HBT.
Linear Transmitter Architectures
- Doherty RF Power Amplifiers.
- Outphasing transmitters.
- Pre-distortion (closed loop RF).
- Control features: RF output blanking (enable/disable), EMI filtering, gain/power control (external/automatic), temperature compensation (open/closed loop), and telemetry.
- Protection and filtering: DC input protection, RF input and output protection, over temperature shutdown, bias sequencing, EMI filtering
- Control Interfaces: TTL/CMOS logic, I2C, USB, etc.
DC Power Management and Design
- ON/OFF to a complete power management system with several levels of voltage conversion and inversion, protection circuitry, noise and EMI filtering.
- RF design concepts; specified RF power amplifier design or as a stand-alone module for virtually any electronic or electrical apparatus.
- Switching DC-DC: Buck, Boost, Buck-Boost.
- Under and over voltage lockout (UVLO/OVLO).
- In-rush, total current limiting.
- Reverse polarity, ESD, lighting protection.
- Noise and EMI filtering.
- Bias sequencing.
- LED Drivers.
- Low Drop Out (LDO) Linear.
Expert Witness Experience
- California Superior Court: Civil litigation, testifying expert.
- International Trade Commission: Consulting (Subject Matter Expert).
- U.S. District Court.
Undisclosed Company, Principal and Owner, 2012 - Present
- Patent litigation - Technical Due Diligence
- Civil litigation
Design Consulting Projects
- Ku-band SSPA, C-band SSPA
- Ultra high efficiency wireless charging
- High speed LTCC optical communications module
- Ultra compact high efficiency load adaptable power amplifier
- Design Consultant - DARPA MIS superconductor fabrication program
New Business and Patent Support
- Served numerous international and domestic clients, from Fortune 100 companies to startup/venture organizations.
- Patent technical analysis.
- Analysis of prior art, and claims.
- Infringement contention charts.
- Claim construction.
- Expert witness reports.
- Reverse engineering.
- Expert Testimony.
Mercury Systems, Inc., Chelmsford, MA, Technical Director, 2013 - 2014
- Full profit and loss responsibility for Mercury's $2.5 million RF power amplifier business unit.
- Responsible for engineering, sales, operations, manufacturing, and test.
- Developed new business opportunities through direct customer engagement and proposals.
- Led and managed new product development and sustaining engineering.
- Managed development and production, material planning, product testing.
University of Colorado, Boulder, CO, Professor, 2013 - 2016
- Course Instructor, ECEN3250 (Microlectronics).
- Ph.D. committee member.
Honors & Publications
- Korean (Conversational)
Academic and Professional Affiliations
- Institute of Electrical and Electronics Engineers-IEEE Member
- Author and Co-Author of publications in peer reviewed journals
- Ph.D. Electrical and Computer Engineering, University of California, Santa Barbara, CA
- B.A. Physics, University of California, Berkeley, CA