Reduced Harmonic Errors by Geometrically Modulating the Demagnetizing Fields in Wave-Type Anisotropic Magnetoresistance Angle Sensors

Anisotropic Magnetoresistance (AMR) angle sensors are widely utilized in industrial applications owing to their non-contact operation, cost efficiency, and miniaturization potential. However, harmonic distortion inherent in AMR measurements fundamentally limits angle encoder accuracy. This work introduces a high-precision AMR sensor employing a wave-type topology that suppresses harmonic errors through geometric innovation, demonstrating significant performance enhancements versus conventional strip-type sensors: 64.3% reduction in maximum angular error (0.50° vs. 1.4°), 65.3% lower worst-case nonlinearity (0.2% vs. 0.576%), and minimal change in repeatability (0.14° vs. 0.137°). Systematic evaluation of dynamic responses under variable field angles through Stoner–Wohlfarth modeling and experimental validation exhibits excellent agreement, confirming curvature optimization effectively minimizes angular errors. Mechanistic analysis identifies demagnetizing fields and induced anisotropy as dominant error sources. Crucially, this architecture maintains fabrication simplicity, demonstrating exceptional cost-performance synergy for automotive, robotics, and industrial automation applications requiring sub-0.5° accuracy.