Does anyone have an idea how to measure accurately the loss resistor (Rs) and inductance (Ls) of a coil at a high RF drive level?
I have to do that with a ferrite core coil (L=2.0uH, core dimensions 8x65mm) at a RF drive level of 50 Vrms or 265 mArms and f=15MHz.
The maximum measurement error should be for Rs = 10% and for Ls = 1 %.
Note: Both Ls and Rs normally depend on the material properties of the ferrite core, the AC flux density and the frequency f. I am also interested how to measure changes of the amplitude permeability and the loss (both vs. RF drive level) of the core material at 15MHz.
Measurements of Ls and Rs at very low RF drive level are no problem for me, because I can do this with an impedance analyzer (Agilent 4294A). But the 4294A current drive capability is limited to 20mArms and cannot be boosted.
I have to do that with a ferrite core coil (L=2.0uH, core dimensions 8x65mm) at a RF drive level of 50 Vrms or 265 mArms and f=15MHz.
The maximum measurement error should be for Rs = 10% and for Ls = 1 %.
Note: Both Ls and Rs normally depend on the material properties of the ferrite core, the AC flux density and the frequency f. I am also interested how to measure changes of the amplitude permeability and the loss (both vs. RF drive level) of the core material at 15MHz.
Measurements of Ls and Rs at very low RF drive level are no problem for me, because I can do this with an impedance analyzer (Agilent 4294A). But the 4294A current drive capability is limited to 20mArms and cannot be boosted.