Electrical – How to measure the impedance of a given coil?

coilmeasurementresonance

What's the best way to measure the resistance and inductance of a coil at a given frequency? I need these parameters for my LTSpice-Simulation which assumes an RL series circuit.

The coil has 8 windings and is printed on a PCB. The eDesignSuite from STMicroelectronics estimates an inductance of 1.72┬ÁH. DC-resistance is approx. 1.27Ohm (measured).

Will the resistance at 13.56MHz be equal to the DC-resistance? (How can I verify this?)
How can I verify the inductance of the coil at approx. 13.56MHz?

Thanks!

Best Answer

I don't know what kind of equipment you have exactly but if you have a function generator that can output a decent sine signal at 13.56 MHz you should be able to use that in conjunction with an oscilloscope to get a reasonable measurement of the inductance. Be aware that proper probing techniques at these kind of frequencies are necessary in order to get a usable result. This interesting article by Tektronix explains the process quite clearly: https://www.tek.com/document/application-note/capacitance-and-inductance-measurements-using-oscilloscope-and-function-ge