Vswr calculator (mismatch loss calculator, vswr impedance calculator)

The VSWR calculator helps determine the quality of impedance matching in an RF system.
It provides key information on reflection coefficient, return loss and mismatch loss.

Formula used

Γ = (VSWR – 1) / (VSWR + 1)
RL = -20 × log₁₀(Γ)
ML = -10 × log₁₀(1 – Γ²)

Explanation

Γ represents the reflection coefficient, indicating the proportion of signal reflected by a mismatched impedance.
RL (Return Loss) shows the power lost by reflection in decibels, while ML (Mismatch Loss) shows the total loss due to mismatch.
A VSWR of 1 corresponds to a perfectly matched system, where Γ = 0, RL and ML are infinite.

Calculation example

For VSWR = 1.5 :
Γ = (1.5 – 1) / (1.5 + 1) ≈ 0.2
RL = -20 × log₁₀(0.2) ≈ 13.98 dB
ML = -10 × log₁₀(1 – 0.2²) ≈ 0.18 dB

Benefits and Use

Allows you to quickly check the impedance matching of an RF line.
Facilitates the reduction of reflection losses in transmission systems.
Useful for RF engineers, technicians and antenna designers.
Helps optimize the overall performance of communication and transmission systems.