1. School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
2. UES, Inc, 4401 Dayton-Xenia Road, Dayton, Ohio 45432, United States
3. Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
4. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States