1. Department of Electrical and Computer Engineers, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
2. Department of Electronics and Information Systems, Ghent University, Technologiepark 126, 9052 Ghent, Belgium
3. Institute of Electronics, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, Poland
4. Institute of Electronics, Lodz University of Technology, ul. Wólczańska 221, 90-924 Lodz, Poland