Magnetoresistive magnetometer with improved bandwidth and response characteristics

We report on the realization and characterization of a high performance, compact magnetometer based on a magnetoresistive sensor and working in the range ±600μT. The output is provided both numerically and by means of a field-proportional voltage. Spurious offset effects are suppressed by flipping the film magnetization at a frequency of 100kHz, 2∕3 orders of magnitude higher than in conventional applications. The design allows for a field resolution of 20nT, low output noise density, and high precision and accuracy (relative full-scale uncertainty of about 500ppm).