Figure 1
From: Inductively-overcoupled coil design for high resolution magnetic resonance imaging
Equivalent circuit diagram of a radio frequency probe consisting of two inductively coupled coils. Circuits in each coil consist of resistive R, capacitive C and inductive L elements. The subscripts p and s denote primary and secondary, respectively. The mutual inductance M between the coils is related to the coefficient of coupling k via the formula 
. v denotes voltage source.