1. Institute of Digital Signal Processing, University of Duisburg-Essen (UDE), Duisburg, Germany
2. Institute for Communications Technology, Technische Universität Braunschweig, Braunschweig, Germany
3. Wireless Devices and Systems Group, University of Southern California, Los Angeles, CA, USA
4. General and Theoreticel Electrical Engineering (ATE), Faculty of Engineering, University of Duisburg-Essen, and CENIDE – Center for Nanointegration Duisburg-Essen, Duisburg, Germany
5. Institute of Microwave Systems, Ruhr University Bochum, Bochum, Germany