It is well-known that any electrical passive element (Resistor, Capacitor,Inductor) contains parasitics that usually manifest themselves at high frequency ranges of operation.
For example, a resistor at DC can be modeled, simply, by just a resistance that depends on the material and geometry of the element. At higher frequencies, parasitic capacitance and inductance start to show up, and this can be experimentally found (for example) by:
Voltage - Current phase difference.
Impedance dependency on frequency.
The same argument is also valid for capacitors and inductors, in which their ideal model is altered and parasitic effects are added at high frequencies.
The plot of Impedance vs. frequency can tell us about these parasitics and when do they start to show up. They will also inform us about the valid frequency range of operation, in which after it, the element no longer behaves normally (An inductor acting as a capacitor after its self resonance frequency (SRF) for example) as shown below:
So when we mention the term "high frequencies", we (probably?) mean beyond the SRF, as elements start behaving as unintended.
Up to my understanding, every passive element generally behaves in a way that I thought of explaining by the figure below:
My questions are somehow interconnected and they are:
Is the concept of figure (2) correct?
In addition to the parasitics that were mentioned above, there seem to be variations in the physical values of L, C, and R themselves (Blue region in figure 2), meaning they all become functions of frequency: R(w), C(w), L(w). Is this true?
I concluded this from:
a. Skin effect for R, making it a function of frequency.
b. Picture #1 above (blue graph). Does the inductance really become negative, or is it the tool we are using that is telling me my inductor value was lost due to the large parasitic capacitance value?
How does the geometrical feature size of the passive element (regardless of its shape) plays a role in determining the frequency separating the green and the blue regions in figure (2)? In other words, is there a way to determine if I have to consider AC effects or not using the knowledge of my feature size?
Can we say line separating the blue and red regions can be represented by the SRF?