1. Telecommunications Department, Faculty of Science Universidad Autónoma de San Luis Potosí (UASLP) San Luis Potosi Mexico
2. Facultad de Ingeniería Mecánica y Eléctrica Universidad de Colima Colima Mexico
3. Electrical Engineering Academic Unit Autonomous University of Zacatecas Zac. Mexico
4. Department of Electrical Engineering University of Chile Santiago Chile