1. Electronic Engineering Division, Aeronautics Institute of Technology, Praça Marechal Eduardo Gomes 50, 12228-900 São José dos Campos, SP, Brazil
2. Microelectronic Laboratory, Polytechnic School, University of São Paulo, Avenida Prof. Luciano Gualberto, Trav 3, 158, 05508-900 São Paulo, SP, Brazil