I have just graduated with a Ph.D. in electrical engineering from the University of Washington’s Sensor Systems Laboratory. Now I’m looking for my next big thing.
I’m a detail-oriented person who excels at solving messy engineering problems with many moving parts. In graduate school, I led several projects from idea to prototype in the area of wireless power transfer systems, working on techniques to increase range, add communication capability, and model the impact of magnetic resonance wireless power systems on human tissue. I have also implemented a custom protocol for streaming of sensor data from neural implants using backscatter, allowing bidirectional communication with low power consumption.
Through both fundamental research and full system prototyping, I’ve acquired a uniquely diverse combination of skills in system design and implementation, firmware development, hardware design and prototyping, electromagnetic analysis and simulation, low-power communication protocol design and implementation with software-defined-radios. It gave me repeated practice in the concept-to-prototype process.
ExtendinG wireless power transfer Range with adaptive coupled relay resonators
A passive relay resonator sympathetically resonates when placed near a wireless power transmitter, and can be used to extend the range of power delivery. A centrally controlled platform of reconfigurable relay resonators can collaboratively and autonomously steer power to nearby receivers quickly and efficiently, covering a large space at high efficiency.
Coil geometry optimization for wireless power delivery to moving receivers
Wireless power transmitter coil design differs greatly based on the application. This is an exploration of coil geometry optimization for delivering power wirelessly to a moving receiver, specifically for a conveyor belt environment in a factory. A working proof-of-concept prototype including both transmitter and receiver was designed and constructed.
Communication By load modulation For Wireless Power systems
Communication between devices in a wireless power system can be highly useful. For instance, communication from the wireless power receiver back to the wireless power transmitter could allow the transmitter to identify a particular receiver and understand its power requirements. Load modulation is a low power communication mechanism involving changing the load condition of wireless power receivers in order to produce a reflection detectable at the power transmitter. The added cost of implementing load modulation in a wireless power system is low, as it can be done as easily as adding a switch to the receiver. This project characterized and implemented load modulation as a communication method in high-quality-factor magnetic resonance system.
Backscatter Data Streaming for implantable medical devices
A high speed data link is desired by neural implants for real-time feedback applications. Backscatter communication is useful for implantable sensors given its power advantages, which lengthens battery life or reduces the charging requirements. I implemented a custom protocol for streaming of sensor data from neural implants using backscatter, allowing bidirectional communication between an embedded MSP430 microcontroller and an external BladeRF software-defined radio.
Tissue Heating Effects of magnetic resonance Wireless Power systemS
This project addresses concerns over wireless power safety. Unlike ionizing radiation sources like X-rays or Gamma rays, the energy carrier in magnetic resonance systems does not have enough energy to ionize atoms or molecules, but it can induce current that causes tissue heating. I used modeling methods to determine which resonant mode of a wireless power transfer system results in the least tissue heating, a result which can inform the design of future wireless power transfer systems intended for use near people.
Impedance Matching for Antennas
Verilog, System Verilog
HFSS, Maxwell, Designer
Code Composer Studio
Vector Network Analyzer
Mixed Domain Oscilloscope
“Large Area Wireless Power Transfer with Coupled Relay Resonators”, Xingyi Shi, Ph.D. dissertation, Dept. of Elect. Eng., Univ. Washington, Seattle, 2019
“Reconfigurable and Adaptive Coupled Relay Resonator Platform for a Moving Receiver”, Xingyi Shi, Joshua R. Smith, IWAT 2019
“Coil Geometry Optimization for Wireless Power Transfer to Moving Receivers”, Xingyi Shi, Huang Lee, Vivek Jain, Joshua R. Smith, WPTC 2018
"Large Area Wireless Power via a Planar Array of Coupled Resonator”, Xingyi Shi, Joshua R. Smith, IWAT 2016
“Co-optimization of Efficiency and Load Modulation Data Rate in a Wireless Power Transfer System,” Xingyi Shi, Aaron N. Parks, Ben H. Waters, Joshua R. Smith, ISCAS 2015
“SAR Distribution for a Strongly Coupled Resonant Wireless Power Transfer System”, Xingyi Shi, Ben H. Waters, Joshua R. Smith, WPTC 2015
“Arsenic in Juice: Apple, Citrus, and Apple-Base”, Denise Wilson, Cassandra Hooper, Xingyi Shi, Journal of Environmental Health, December 2012, vol. 75, no. 5, pp. 14-20
WO/2019/046393: “Wireless Charging Method for Assembly Line”, March 2019
University of Washington, Seattle
Ph.D. Electrical Engineering, WIRELESS POWER TRANSFER
University of Washington, Seattle
B.S. Electrical Engineering