  The magnetic-field behaviour of the off-diagonal impedance in Co-based
amorphous wires is investigated under the condition of sinusoidal (50 MHz) and
pulsed (5 ns rising time) current excitations. For comparison, the field
characteristics of the diagonal impedance are measured as well. In general,
when an alternating current is applied to a magnetic wire the voltage signal is
generated not only across the wire but also in the coil mounted on it. These
voltages are related with the diagonal and off-diagonal impedances,
respectively. It is demonstrated that these impedances have a different
behaviour as a function of axial magnetic field: the former is symmetrical and
the latter is antisymmetrical with a near linear portion within a certain field
interval. In the case of the off-diagonal response, the dc bias current
eliminating circular domains is necessary. The pulsed excitation that combines
both high and low frequency harmonics produces the off-diagonal voltage
response without additional bias current or field. This suits ideal for a
practical sensor circuit design. The principles of operation of a linear
magnetic sensor based on C-MOS transistor circuit are discussed.
