Bipolar Transistor based Magnetogradiometer

In this paper is experimentally determined a mechanism occurring in gradient magnetic field at two-collector bipolar magnetotransistors (BMT) when their collector currents are equal at induction B = 0. The effect represents a linear control of the sum of these currents by the gradient field. This phenomenon transform the BMT’s in magnetogradiometer sensor with high resolution. The experiments are carried out with prototypes realized by integrated silicon processes and innovative magnetomodular system featuring high and linear gradient. The sensitivity of BMT reaches S ≈ 300 μA/T for the selected operation mode. The maximal gradient obtained with new actuator system is 78 mT/mm. The results are very promising, as the magnetogradiometer further extends the functional possibility of BMT for sensor electronics and automation.