AUTOMATIC VECTOR IMPEDANCE MEASUREMENT WITH MINIMUM HARDWARE

A computer-based technique for vector impedance measurement is described. An alternating voltage of specified frequency is impressed across a series combination of the unknown impedance Z and a reference resistance R//o; the voltage to ground and the phase angle at the nodal connection are then measured and recorded. Measurements are repeated after interchanging Z and R//o, and the magnitude and phase of Z and R//o are automatically calculated. Alternatively, Z and R//o are not interchanged, so that the amount of hardware is reduced at the expense of a software algorithm for determining vertical Z vertical and theta . This trade-off simplifies the design and makes it more cost effective.