In this paper, we propose an approximate nonlinear theory of a phase-locked loop (PLL) of the spin torque nano-oscillator (STNO). We study the nonlinear dynamics of a filterless PLL generating microwave oscillations in a broad range of frequencies under the spin-polarized electrical current and external magnetic field. We consider the bifurcation analysis caused by a change in the frequency detuning of synchronized oscillations. We determine the bands of phase locking and quasi-synchronism, which basically distinguish STNOs from other types of microwave oscillators. Finally, we study the amplitude and phase noises of isochronous and nonisochronous STNO-based PLLs and compare them to the analogous characteristics of an autonomous oscillator.

No abstract

No abstract

No abstract

No abstract