[1] Tech Univ Ilmenau, Dept Elect Measurement, Res Lab, POB 100565, D-98684 Ilmenau, Germany
[2] Tech Univ Kosice, Dept Elect & Multimedia Commun, Kosice 04120, Slovakia
[3] Crabbe Consulting Ltd, Stockton On Tees TS19 7LZ, England
[4] Ingenieurburo Ralf Klukas Dresden, D-01257 Dresden, Germany
[5] Vrije Univ Brussel, Dept Elect & Informat, B-1050 Brussels, Belgium
[6] MEODAT GmbH, D-98693 Ilmenau, Germany