The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 29, 2015
Filed:
Sep. 19, 2011
Yuchen Zhou, San Jose, CA (US);
Kunliang Zhang, Fremont, CA (US);
Min LI, Fremont, CA (US);
Kenichi Takano, Saku, JP;
Joe Smyth, Aptos, CA (US);
Moris Dovek, San Jose, CA (US);
Akihiko Takeo, Kunitachi, JP;
Tomomi Funayama, Fuchu, JP;
Masahiro Takashita, Kawasaki, JP;
Masayuki Takagishi, Kunitachi, JP;
Yuchen Zhou, San Jose, CA (US);
Kunliang Zhang, Fremont, CA (US);
Min Li, Fremont, CA (US);
Kenichi Takano, Saku, JP;
Joe Smyth, Aptos, CA (US);
Moris Dovek, San Jose, CA (US);
Akihiko Takeo, Kunitachi, JP;
Tomomi Funayama, Fuchu, JP;
Masahiro Takashita, Kawasaki, JP;
Masayuki Takagishi, Kunitachi, JP;
TDK Corporation, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A method for measuring the frequency in a spin torque oscillator having at least a magnetic oscillation layer (MOL), junction layer, and magnetic reference layer (MRL) is disclosed. In a first embodiment, a small in-plane magnetic field is applied to the STO after a DC current is applied to excite the MOL into an oscillation state. The MRL has a perpendicular magnetization that is tilted slightly to give an in-plane magnetization component to serve as a reference layer for measuring the oscillation frequency of the MOL in-plane magnetization component. An AC voltage change is produced in the DC current as a result of variable STO resistance and directly correlates to MOL oscillation frequency. Alternatively, a field having both perpendicular and in-plane components may be applied externally or by forming the STO between two magnetic poles thereby producing an in-plane magnetization reference component in the MRL.