VSWR, Reflection Coefficient and Return Loss Calculator

Start from the reflection coefficient magnitude, the VSWR or the return loss and get the other two, plus the share of power reflected and the mismatch loss.

Calculator

|Γ|
0.2
VSWR
1.5
Return loss
13.98 dB
Power reflected
4%
Mismatch loss
0.1773 dB

Type numbers like 4.7, 0.002 or 2e-3. Results are rounded to 4 significant figures.

The formulas

S=1+∣Γ∣1−∣Γ∣∣Γ∣=S−1S+1\begin{gathered} S = \dfrac{1 + |\Gamma|}{1 - |\Gamma|} \\ |\Gamma| = \dfrac{S - 1}{S + 1} \end{gathered}

S (VSWR) is at least 1; |Γ| is from 0 (matched) to 1 (open or short).

RL=−20log⁡10∣Γ∣RL = -20\log_{10}|\Gamma|

Return loss in dB, positive for a passive load; bigger means a better match.

ML=−10log⁡10(1−∣Γ∣2)ML = -10\log_{10}(1 - |\Gamma|^2)

Mismatch loss in dB. |Γ|² is the fraction of the incident power reflected.

  • These use only the magnitude of Γ. To find the load impedance you also need its phase, from the position of the first voltage minimum.

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