1. Fraunhofer Institute of Microelectronic Circuits and Systems, D-47057 Duisburg, Germany. E-mail: Omar.Elkhalili@ims.fraunhofer.de
2. Fraunhofer Institute of Microelectronic Circuits and Systems, D-47057 Duisburg, Germany
3. Siemens AG, Corporate Technology, D-81730 Munich, Germany. E-mail: Peter.Mengel@siemens.com
4. Siemens AG, Corporate Technology, D-81730 Munich, Germany