[1] Univ Texas Arlington, Dept Elect Engn, Arlington, TX 76019 USA
[2] Texas Tech Univ, Elect & Comp Engn Dept, Lubbock, TX 79424 USA
[3] Natl Inst Space Res INPE, Associated Plasma Lab LAP, BR-12227010 Sao Jose Dos Campos, Brazil
[4] Tsinghua Univ, Dept Elect Engn, Beijing 100084, Peoples R China
[5] Chongqing Univ, Coll Elect Engn, Dept High Voltage & Insulat Technol, Chongqing 400044, Peoples R China