Patent ID: 8879205

Claim:
A microwave-assisted magnetic recording (MAMR) head, comprising: a main magnetic pole; a spin-torque oscillator (STO) positioned near the main magnetic pole, the STO comprising: a first perpendicular magnetic layer positioned above the main magnetic pole, wherein the first perpendicular magnetic layer is a first spin polarization layer (SPL 1 ) having an axis of magnetic anisotropy in a direction of film thickness that is perpendicular to a film surface; a first non-magnetic transmission layer (spacer layer 1 ) positioned above and directly adjacent the first perpendicular magnetic layer; a magnetic layer effectively having a plane of easy magnetization in the film surface positioned above and directly adjacent the first non-magnetic transmission layer, the magnetic layer being a field generation layer (FGL); a second non-magnetic transmission layer (spacer layer 2 ) positioned above and directly adjacent the magnetic layer; and a second perpendicular magnetic layer positioned above and directly adjacent the second non-magnetic transmission layer, wherein the second perpendicular magnetic layer is a second spin polarization layer (SPL 2 ) having magnetic anisotropy in the direction of film thickness that is perpendicular to the film surface, wherein one of the first and second perpendicular magnetic layers is configured to undergo T-mode oscillations with the FGL, and wherein another of the first and second perpendicular magnetic layers is configured to undergo U-mode oscillations with the FGL.