Piconics Method of Measurement for Self Resonance Frequency in RF Air coil and Conial Inductors
Piconics S-parameter measurements are taken using an Anritsu 37269B Vector Network Analyzer and Anritsu 3680K Universal Test Fixture. The S-parameters are 2 port measurements of the RF coil mounted to a 10 mil Alumina substrate with a 50 Ohm microstrip trace.
Piconics measures resonance of these coils with the coil mounted as a shunt element approximating typical usage. The frequency of resonance is chosen where the phase changes from negative to positive indicating that the coil has become capacitive.