Low-Frequency Noise and Detectivity Analysis of Planar Hall Magnetoresistance Sensors for Applications

Abstract

We studied noise and detection performance of planar Hall magnetoresistance (PHMR) sensors, specifically cross-junction and multi-ring sensors. The sensors were characterized in 0.5 Hz-200 Hz, and their ability to detect magnetic field in an unshielded environment was evaluated. The external magnetic field was applied parallel and perpendicular to the easy axial direction, and the resulting spectrum was measured. By optimizing the sensor structure, the resolution was enhanced at low frequencies, indicating good detection values. The results demonstrate that PHMR sensors are universal, high-performance magnetometers that can applies to a variety of applications. Moreover, the field resolution of the PHMR sensor can open new opportunities for biomagnetic signal detection, and the sensor can have industrial applications in harsh environments.