Doctoral Dissertations


Chunyu Wu

Keywords and Phrases

AC-DC power supply; Conducted EMI; Equivalent dipoles; Near-field measurement; RF de-sense; Wireless power transfer


“As internet-of-things (IoT) applications surge, wireless connectivity becomes an essential part of the network. Smart home, one of the most promising application scenarios of IoT, will improve our life quality enormously. However, electromagnetic interference (EMI) to the receiving antenna, either from another electronic product or from a module/an integrated circuit(IC) inside the same wireless device, will degrade the performance of wireless connectivity, thus influencing the user experience. Characterization and modeling of the EMI become increasingly important.

In the first part, an improved method to extract equivalent dipoles from magnitude- only electromagnetic-field data based on the genetic algorithm and back-and-forth iteration algorithm is proposed. The method provides an automatic flow to extract the equivalent dipoles from electromagnetic-field data on arbitrarily shaped scanning surfaces and minimizes the number of extracted dipoles. In the second part, both the differential mode (DM) and common mode (CM) EMI below 1 MHz from the ac-dc power supply in a LED TV is analyzed and modeled. Through joint time-frequency analysis, the drain-to-source voltage of the power MOSFET in the power factor correction (PFC) converter is identified as the dominant noise source of both CM and DM EMI below 1 MHz from the power supply. The current paths of DM and CM EMI are explained and modeled by a linear equivalent circuit model. In the last part, the noise source and current path of the conducted CM EMI noise from a Qi-compliant wireless power transfer (WPT) system for mobile applications are analyzed. The analysis and modeling explain the mechanism of the CM EMI noise and provide guidelines to reduce the CM EMI noise”--Abstract, page iv.


Fan, Jun, 1971-

Committee Member(s)

Beetner, Daryl G.
Ferdowsi, Mehdi
Khilkevich, Victor
Fu, Yanjie


Electrical and Computer Engineering

Degree Name

Ph. D. in Electrical Engineering

Research Center/Lab(s)

Electromagnetic Compatibility (EMC) Laboratory


Missouri University of Science and Technology

Publication Date

Fall 2020

Journal article titles appearing in thesis/dissertation

  • A hybrid algorithm of genetic algorithm and improved iteration algorithm for extraction of equivalent dipoles from magnitude-only electromagnetic fields
  • Analysis and modeling of conducted EMI from an AC-DC power supply in LED TV up to 1 MHz
  • Analysis and modeling of the conducted common-mode EMI from wireless power transfer systems for mobile applications


xii, 81 pages

Note about bibliography

Includes bibliographic references.


© 2020 Chunyu Wu, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11804

Electronic OCLC #