Microfabricated fluxgate sensors with low noise and wide bandwidth

Miniature fluxgate magnetic sensors have been micro-fabricated using thin f ilm planar technology on glass substrates. The 1000 x 200 mu m sensors comp rise a copper multilayer solenoid winding with a thin amorphous cobalt allo y core deposited by RF magnetron sputtering. The bandwidth and sensitivity of a closed-loop sensor system using these novel devices is 0-2.5MHz and 50 00V/T, respectively, with a spectral noise density of 2nT/root Hz at 10kHz.