Calculate impedance using S11 reflection, S21 series & S21 shunt

This calculator allows calculation of impedance from S11 using S11 reflection; S21 series; and S21 shunt (all S parameters wrt 50Ω). Note:

impedance is a complex quantity, it has real and imaginary parts or magnitude and phase, likewise for admittance.

The results are valid only for linear circuits.

Inputs:

	Real /magnitude	Imaginary / angle


Results:
Zx (Ω)
Yx (S)

The calculator does not do a lot of error checking, if you enter nonsense, it will probably produce nonsense.

It is worth noting that accurate S21 measurements depend on 12 term correction of the VNA, a point overlooked by many proponents of the series and shunt measurement techniques.

Links / references

Agilent. Feb 2009. Impedance Measurement 5989-9887EN.
Agilent. Jul 2001. Advanced impedance measurement capability of the RF I-V method compared to the network analysis method 5988-0728EN.

Changes

Version	Date	Description
1.01	27/10/2019	Initial.
1.02
1.03
1.04
1.05