RFID tag, simulation and schematics
Here's a drawing I made to demonstrate how a magnetic field gets coupled to a coil located at some distance from it: -



You have a transmitter coil (shown in red). It has a current flowing through it and it might be 1 turn or several turns; the upshot is amps x turns is MMF (magnetomotive force) drives the magnetism emitted from the coil and at a distance Z, the flux density is shown in the formula.

This flux density can be largely thought of as being constant (at distance Z) and impinges on a receive coil of area A. Flux density x area gives total flux and the total voltage received is: -

\$N\dfrac{d\phi}{dt}\$

This basically means that a higher frequency gives you a higher voltage induced in the receive coil and if you know what frequency, B\$_Z\$ and receive antenna area you can determine the voltage induced.

This basic setup is much improved by the use of tuning with parallel capacitors at send end and receive end (as per your diagram). For a given stimulus on the transmit coil of a few volts, you might be able to elicit several amps RMS by choosing a capacitor that resonates with the coil inductance: -

\$f_{RES} = \dfrac{1}{2\pi\sqrt{LC}}\$

Similarly, at the receiving end you can multiply the voltage received by fairly large factors (in excess of ten) by parallel tuning the receive coil with an appropriate capacitor. Same formula as above.

This should hopefully be enough voltage to get an energy harvesting chip to charge up a capacitor to a few volts dc and therefore be suitable enough for a small microcontroller to operate.

So, if you want to play with ideas in your simulator try making a transformer with coupling coefficient k where k is a very small value that represents the fraction of magnetic field received by the receive coil, based on the formula in the diagram at the top of this answer.