1. Ruhr University Bochum,Chair of Applied Electrodynamics and Plasma Technology,Department of Electrical Engineering and Information Science,Bochum,North Rhine-Westphalia,Germany
2. Ferdinand-Braun-Institute,Leibniz-Institutfür Höchstfrequenztechnik (FBH), Berlin,Berlin,Germany
3. Ruhr University Bochum,Chair of Theoretical Electrical Engineering,Department of Electrical Engineering and Information Science,Bochum,North Rhine-Westphalia,Germany