1. College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
2. Nanjing Rongce Testing Technology Ltd., Nanjing, China
3. Electromagnetic & Electrochemical Technologies Department, Electromagnetic Technologies Group, National Physical Laboratory, Teddington, U.K.
4. Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, U.K.