[1] Univ Utah, Dept Elect & Comp Engn, Salt Lake City, UT 84112 USA
[2] Ecole Polytech Fed Lausanne, Integrated Syst Lab, Lausanne, Switzerland
[3] Rhein Westfal TH Aachen, Inst Werkstoffe Elektrotech 2, Aachen, Germany
[4] Rhein Westfal TH Aachen, JARA FIT, Aachen, Germany
[5] Nanyang Technol Univ, Sch Comp Engn, Singapore, Singapore