AC-impedance measurement

Thread Starter


Joined May 16, 2022

I am currently trying to measure the AC-impedance of a coil (just one loop) I build with a simple copper cable. My approach was to measure the S-values for this specific part and wanted frequency with a VNA (Vector Network Analyzer) and calculate the impedance Z according to the measured values. The problem that appeared was that the imaginary impedance had an expected value but the real impedance had a value of about 1.5 Ohm what was way too much compared what I calculated regarding to the skin effect that plays a role for measurements at these frequencies (appr. 83 MHz). My question is: Does anybody know what could have caused this result? Is the approach for the calculation wrong? Or could the soldered junctions between the cable and the SMA-connectors have caused this high impedance?
If somebody has another idea how we could measure the AC-impedance at a specific frequency I would also be interested in your ideas.

I would greatly appreciate it if someone could help me with this problem.
Thanks in advance!