**Author details**

Hossam Selim1 , Fernando Piñal Moctezuma2 , Miguel Delgado Prieto2 \*, José Francisco Trull1 , Luis Romeral Martínez<sup>2</sup> and Crina Cojocaru1

1 Physics Department, Technical University of Catalonia, Terrassa, Barcelona, Spain

2 Electronics Engineering Department, Technical University of Catalonia, Terrassa, Barcelona, Spain

\*Address all correspondence to: miguel.delgado@mcia.upc.edu

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
