Time-frequency study of spintronic oscillators based on Hilbert-Huang Transform

We propose and develop an advanced signal processing technique that, combined with micromagnetic simulations, is able to deeply describe the non-stationary behavior of spin-torque oscillators, both in terms of time domain and spatial distribution of the magnetization dynamics. The Hilbert-Huang Transform is used for the identification of the time traces of each oscillation in a multimode excitation. Overall performance indicates a route for a complete characterization of time-frequency domain data of a STO, pointing out that the HHT methodology developed is general and can be also used for a variety of other different scenarios.