Improvement of the /spl mu/-Hall magnetic sensor sensitivity at low frequency

We have developed a configuration for precision magnetic measurements associating a /spl mu/-Hall sensor, a modulated ferromagnetic antenna, and an analog electronic circuitry. This association is not only able to remove the 1/f noise of the Hall sensor, but also to achieve an ultimate noise level even lower than thermal white noise of the Hall sensor. The system main characteristics are the follo...