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**.