MR vector sensor with trimmable sense axis direction

Magnetoresistive bridge sensors fabricated from thin-film Permalloy elements are biased by mutually opposing fields on adjacent arms of the bridge using integral thin-film bias magnets. The sensors have excellent vector response and good linearity in applied fields up to 1.5 Oe. It is shown both theoretically and experimentally that the axis of peak sensitivity is not aligned with any geometric edge of the sensor pattern but can be adjusted by varying the bias field. This ability to trim the sense-axis direction is discussed in relation to the production of three-axis sensor systems