1. Department of Electrical and Computer Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, USA
2. Department of Physics, State University of Maringá, Maringá, PR 87020-900, Brazil
3. Department of Physics, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil
4. Nuclear and Energy Research Institute, São Paulo, SP 05508-000, Brazil