A simple method for measuring and sorting RF coils based on the inductance and quality factor

This article presents a simple and inexpensive method for measuring and sorting RF coils at their operating frequency or very close to it. The process is based on the injection of a linear variable frequency constant current in a circuit consisting of an identified value capacitor and the coil under test. The range of frequencies includes the working frequency of the measured coil. The resonant circuit voltage is detected and measured by using an analog to digital converter. From the resonance curve thus obtained, we calculate the exact values of the inductance and quality factor.