1. Faculty of Sciences and Techniques, Electrical and Electronics Engineering Laboratory, Marien Ngouabi University, Brazzaville BP 69, Republic of Congo
2. Electrical and Electronics Engineering Laboratory, Marien Ngouabi University, Brazzaville BP 69, Congo
3. Electrical Engineering Department, Grenoble Alpes University, CNRS, Grenoble INP, G2ELab, 151 Rue de la Papeterie, Saint-Martin d’Hères F-38400, France