1. Faculty of Sciences and Techniques, Marien Ngouabi University, Brazzaville, Congo
2. Electrical and Electronics Engineering Laboratory, Marien Ngouabi University, Brazzaville, Congo
3. Department of Electrical Engineering, Univ. Grenoble Alpes, CNRS, Grenoble INP, G2ELab, Saint-Martin d’Hères, France