Patent ID: 8823460

Claim:
An apparatus comprising a radiofrequency oscillator, said radiofrequency oscillator comprising a magnetoresistive device within which there flows a spin-polarized electrical current to generate an oscillating signal oscillating at an oscillation frequency on an output terminal, said device comprising a stack comprising a reference layer, a free layer, and a spacer layer, said reference layer being a magnetic layer capable of spin-polarizing electrical current, and having a magnetization of fixed direction, said free layer being a magnetic layer having a magnetization that can oscillate when crossed by a spin-polarized current, and said spacer layer being a non-magnetic layer interposed between said free layer and said reference layer to form one of a tunnel junction and a spin valve, a current source to cause a current of electrons to flow in a direction perpendicular to said free layer, said reference layer, and said spacer layer, a control terminal to control at least one of a frequency and an amplitude of said oscillating signal, and a feedback loop connected between said output terminal and said control terminal, said feedback loop comprising an amplifier equipped with an input connected to said output terminal so as to amplify a part of said oscillating signal at said output terminal, and an output connected to said control terminal so as to inject, into said control terminal, an amplified part of said oscillating signal in phase with said oscillating signal at said output terminal.