1. SENSOR Laboratory, Department of Information Engineering (DII), University of Brescia, Via Valotti 9, 25133 Brescia, Italy
2. Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze, 7/A, 43124 Parma, Italy
3. Institute of Materials for Electronics and Magnetism Istituto dei Materiali per l’Elettronica e il Magnetismo (IMEM)—Consiglio Nazionale delle Ricerche (CNR), Parco Area delle Scienze, 37/A, 43124 Parma, Italy