Method of measuring and sorting coils using a frequency synthesizer

The paper presents a simple procedure used for measuring and sorting RF coils using a sinusoidal signal generated by a frequency synthesizer. The sinusoidal signal is applied to a circuit made up of coils with unknown inductance and a capacitor with known value. By measuring the resonance frequency and the level of the envelope, one can calculate the inductance and the quality factor. As the frequency of the input signal varies step by step, there occur transient regime effects which alter the results. The paper looks at the conditions which lead to the elimination of these effects.