transformer S11 simulation

I am building the transformer by using two inductors coupled with each other. Each inductor is a squred shape matal, and the two indcutors interweaving with each other.


In ADS simulation, the input port is 50 ohms. From SP simulation, I get S11. But I dont know which factor influences the input impedance of the transformer. Does anyone know? Thank you.

There are:
a) ohmic (or DC) resistance of the wire
b) reactive impedance resulting from Henry value and frequency
c) load on the secondary winding influences flux building and collapsing, which influences Ampere level, which is related to impedance.

The above list is not complete, of course. Transformers are complicated animals.

Imagine an equivalent circuit of a standard transformer .. Not necessarily RF one, just a standard transformer.
Which intrinsic and extrinsic elements define the Input Impedance ?
-Primary Inductance
-Secondary Inductance
-Coupling factor ( evidently Mutual Inductance )
-Lossy Elements ( internal resistances,core losses,substrate losses etc.)
-And Load..