1. Institute of Electrical and Information Engineering–Microwave Laboratory, Faculty of Engineering, Christian-Albrechts-Universität zu Kiel, Kaiserstraße 2, D-24143 Kiel, Germany
2. Faculty of Engineering, Institute for Materials Science, Christian-Albrechts-Universität zu Kiel, Kaiserstraße 2, D-24143 Kiel, Germany
3. Fraunhofer Institute for Silicon Technology ISIT, Fraunhoferstraße 1, D-25524 Itzehoe, Germany