Calculation of inductance and Q from S parameter

For Single-ended inductor (equations valid in ADS):

L(f)=imag(1/y11)/(2*pi*f);
Q(f)=imag(1/y11)/real(1/y11);

For differential inductor:

Z=z11+z22-z12-z21;
L(f)=imag(Z)/(2*pi*f);
Q(f)=imag(Z)/real(Z);