# Calculate Loss from s11 and s21

This calculator calculates Loss from |s11| and |s21|. Loss=PowerIn/PowerOut.

 Inputs: Real /magnitude Imaginary / angle s11 S11 Real,Imaginary S11 ρ,θ(°) S11 ρ,θ(ᶜ) S11 ρ(dB),θ(°) S11 ρ(dB),θ(ᶜ) s21 S21 Real,Imaginary S21 ρ,θ(°) S21 ρ,θ(ᶜ) S21 ρ(dB),θ(°) S21 ρ(dB),θ(ᶜ) s21 adjustment (dB) Results: Insertion Loss Insertion Loss (dB) Loss Loss (dB) MismatchLoss MismatchLoss (dB)

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

Inputs are assumed wrt 50+j0Ω.

The calculator needs only the magnitude of s11 and s21, but it will accept several formats from which it can calculate the magnitude. If you only know the magnitude, enter values like Example 1 (in dB), or Example 2.

Example 3 is an extract of a .s2p file of meaurement of a 1:8 transformer with a 3.3k resistor in series with Port 2. The power dividing action of the 3.3k resistor and Port 2 has 18.26dB loss, so the transformer loss is 18.49-18.26=0.23dB.

Example 4 is the same as Example 3, but the s21 adjustment is used to adjust for the 18.26dB of loss at Port 2 due to the power dividing action of the 3.3k resistor (log(50/3350)=-18.26dB).