The Return Loss to VSWR calculator converts the Return Loss of an RF system to a Voltage Standing Wave Ratio (VSWR).
This is useful for evaluating impedance matching in transmission lines and antennas.
Formula used
Γ = 10^(-RL/20)
VSWR = (1 + Γ) / (1 – Γ)
Or :
RL = Return Loss in dB
Γ = reflection coefficient (linear)
VSWR = voltage standing wave ratio
Explanation
Return loss (RL) measures the reflected power relative to the incident power in an RF system.
The reflection coefficient Γ translates this reflected power into a linear value.
The VSWR indicates the quality of the impedance matching: a VSWR close to 1 means excellent matching, while a high VSWR indicates strong reflection.
Calculation example
For a Return Loss of 20 dB :
Γ = 10^(-20/20) = 0.1
VSWR = (1 + 0.1) / (1 – 0.1) = 1.22
Benefits and Use
- Allows you to quickly assess the impedance matching quality of an RF system.
- Useful for RF engineers and technicians to minimize losses and reflections.
- Helps optimize the performance of antennas, coaxial cables and transmission lines.
- Clearly indicates if adjustments are needed to reduce reflections.
