A simple method of characterizing high-frequency inductors under large excitation

A simple method is presented by which high-frequency inductors can be characterized under large excitation by using a general-purpose digital oscilloscope. The method uses numerical multiplication to measure phase difference between two sinusoidal waveforms from which L and Q are calculated using the phase diagram relationship. Factors affecting accuracy of the method are analyzed based on the sensitivity function. A method is also presented by which influences of parasitic elements across a current sensing resistor can be removed. The accuracy of the method is evaluated by characterizing an air-core inductor (10.1 /spl mu/H) which is easily characterized by an impedance analyzer. Inductance and quality-factor (/spl sime/100) at 1 MHz were measured in good accuracy. Planar inductors using NiZn ferrite substrates are characterized at 1 MHz by this method.<
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