Use this tool to calculate the Reflection Coefficient Γ from S11. The reflection coefficient Γ is a measure of impedance mismatch at a transition in an RF circuit. It is a positive value between 0 and 1.
Enter
- S11 – either linear or dB value can be used
Background
S11 is the input reflection coefficient with a value between 0 and 1. (Entering values outside this range will result in meaningless output). Referring to the picture of a two port network shown below, S11 = b1/a1 (when a2=0)
Formula
if S11 is expressed as a linear quantity,
Γ = S11
On the other hand, if S11 is expressed in dB
Γ = 10(S11dB/20)
Example Calculations
If the reflected signal b1 = 0, then all of the input signal a1 is transmitted forward and the reflection coefficient Γ = 0.
If all of the input signal is reflected back, then b1=a1 and none of it is transmitted forward. This is the poorest match possible and the reflection coefficient Γ = 1.