Patent ID: 7298597

Claim:
A magnetoresistive sensor capable of sensing external magnetic fields comprising: a substrate; an electrically conductive strip on the substrate and having first and second ends; a first tunnel barrier on the strip at the first end; a free ferromagnetic layer on the first tunnel barrier and having an in-plane magnetization direction oriented substantially in a first direction in the absence of an external magnetic field, said free layer magnetization direction being substantially free to rotate in the presence of an external magnetic field; a ferromagnetic biasing layer magnetically-coupled to the free layer and having an in-plane magnetization direction oriented substantially orthogonal to said first direction in the absence of an external magnetic field; and an electrically-conducting spacer layer between the biasing and free layers, the spacer layer between the biasing and free layers inducing substantial orthogonal magnetic coupling of the free layer to the biasing layer; a second tunnel barrier on the strip at the second end; and a fixed ferromagnetic layer on the second tunnel barrier and having an in-plane magnetization direction oriented in a second direction substantially orthogonal to said first direction and substantially prevented from rotation in the presence of an applied magnetic field.