1. Department of Physics, Electronics Laboratory, University of Patras, GR-26504 Rio Patras, Greece
2. Department of Electrical Engineering, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates
3. Nanoelectronics Integrated Systems Center (NISC), Nile University, Giza 12677, Egypt
4. Department of Electrical and Software Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada