Improved Current Shunt Characterization Method for Core Loss Measurement


With the increasing switching frequencies and power densities in modern power converters, magnetic core losses are becoming more essential for efficiency and thermal optimization. Traditionally, the two-winding method suffers from sensitivity to phase error in practical measurements; this is mainly created by the unknown phase shift of a current-sensing resistor. Several methods have been developed to characterize the phase shift of a current shunt resistor; however, the load effects of oscilloscopes are ignored. As a result, the corresponding phase shift can be significantly underestimated. This paper proposes an improved method for phase shift extraction of a current shunt to solve the problem. The effectiveness of the shunt characterization method is experimentally verified up to 50 MHz. Benefits from the proposed method, the time-consuming component tuning process is not required for core loss measurement. A measurement verification at 10 MHz shows its validity. Finally, a current shunt implemented with a coaxial resistor array is designed with a phase shift of 0.05⁰ at 10 MHz and a parasitic inductance as low as 42 pH.


Electrical and Computer Engineering

Research Center/Lab(s)

Electromagnetic Compatibility (EMC) Laboratory

Publication Status

Early Access


This paper is based upon work supported partially by the National Science Foundation under Grant No. IIP-1916535.

Keywords and Phrases

Coaxial Resistor; Core Loss; Core Loss; Current Measurement; Current-To-Voltage Impedance; Impedance; Loss Measurement; Resistors; Transmission Line Measurements; Two-Port Resistor; Voltage Measurement

International Standard Serial Number (ISSN)

1941-0107; 0885-8993

Document Type

Article - Journal

Document Version


File Type





© 2022 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

10 Feb 2022