**Author details**

Ernesto Limiti and Patrick E. Longhi\* Electronic Engineering Department, University of Rome Tor Vergata, Rome, Italy

\*Address all correspondence to: longhi@ing.uniroma2.it

© 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.
