Free · Physics models
Finite RF Standing-Wave and Mismatch Loss
Convert between VSWR, reflection magnitude, reflected power and finite return or mismatch loss.
- Formula & worked example
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Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
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Formula and method
reflection coefficient = 0.33333; reflected power percentage = 11.111. This worked example uses the displayed units and declared assumptions.
reflection_coefficient = (vswr - 1)/(vswr + 1); reflected_power_percentage = 100 * reflection_coefficient^2; return_loss = -20 * log(reflection_coefficient) / log(10); mismatch_loss = -10 * log(1 - reflection_coefficient^2) / log(10); through_power_percentage = 100 - reflected_power_percentage
Worked example
Enter these known values and leave the other values blank.
- VSWR
- 2 (: 1)
- Reflection coefficient (Γ)
- 0.3333
- Reflected power
- 11.11 %
- Through power
- 88.89 %
- Return loss
- 9.542 dB
- Mismatch loss
- 0.5115 dB
Assumptions and limitations
- This is the finite passive mismatch branch with 1<VSWR<∞ and 0<|Γ|<1. A perfect match has infinite return loss; total reflection has infinite VSWR and mismatch loss. Percentages refer to incident power, and reflection phase is not determined.
- Clear an unknown to solve a supported inverse; keep known values fixed with locks. Singular or underdetermined inverses may remain incomplete.
Common questions
What assumptions apply?
This is the finite passive mismatch branch with 1<VSWR<∞ and 0<|Γ|<1. A perfect match has infinite return loss; total reflection has infinite VSWR and mismatch loss. Percentages refer to incident power, and reflection phase is not determined.
Which unknowns can I solve?
Editable controls preserve the supported captured inverse branches. Clear the desired unknown and provide enough independent known quantities; singular or underdetermined inverses may remain incomplete.
References
This finite loss branch requires VSWR greater than one. A perfect match has infinite return loss. Reflection magnitude must be strictly between zero and one for finite losses. Finite loss calculations require reflected power strictly between zero and 100 percent. Finite loss calculations require transmitted power strictly between zero and 100 percent.