Antenna VSWR, Return Loss (dB), Reflection Coefficient & Mismatch Calculator

Convert antenna VSWR into Return Loss (dB) and reflected transmitter watts.

Return Loss (dB)
13.98 dB
Net Radiated Forward Power 96 W
Reflected Power Percentage 4 %
Reflection Coefficient (Γ) 0.2 Γ
Inputs
: 1
Measured Voltage Standing Wave Ratio (VSWR ≥ 1.0).
W
Forward transmitter RF output power in Watts.
Results & Graph
Return Loss (dB)
13.98 dB
Net Radiated Forward Power
96 W
Reflected Power Percentage
4 %
Reflection Coefficient (Γ)
0.2 Γ

Return Loss (dB)

Graph 1 • Vswr Ratio Sensitivity Recalculates the domain equation across 50% to 150% of the primary input while holding other parameters constant.
0 dB 35.7 dB 71.3 dB 50%: 66.02 dB 66.0 50% 75%: 24.61 dB 24.6 75% 100%: 13.98 dB 14.0 100% 125%: 10.33 dB 10.3 125% 150%: 8.3 dB 8.3 150%
Graph 2 • Primary & Supporting Metric Comparison Compares the primary output alongside supporting domain benchmarks.
Return Loss (dB) 13.98 dB Net Radiated Forward Power 96 W Reflected Power Percentage 4 % Reflection Coefficient (Γ) 0.2 Γ
Graph 3 • Exact Output Table & Units Displays each calculated output in its exact domain unit.
Return Loss (dB)13.98 dBNet Radiated Forward Power96 WReflected Power Percentage4 %Reflection Coefficient (Γ)0.2 Γ
Summary: A 1.5:1 VSWR corresponds to 13.98 dB Return Loss (Γ=0.2), reflecting 4% (4 W) and radiating 96 W.
Summary: A 1.5:1 VSWR corresponds to 13.98 dB Return Loss (Γ=0.2), reflecting 4% (4 W) and radiating 96 W.
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Formula & Mathematical Methodology: VSWR & Return Loss Physics & Engineering Equation

Γ = VSWR − 1VSWR + 1
ReturnLossdB = −20 × log₁₀(Γ)
ReflectedPower% = Γ² × 100
Γ = (VSWR − 1) / (VSWR + 1); ReturnLoss_dB = −20 × log₁₀(Γ); ReflectedPower% = Γ² × 100
  • vswrRatio: Vswr Ratio (: 1)
  • forwardTransmitterWatts: Forward Transmitter Watts (W)

Rounding: Physical constants follow CODATA/NIST values; output quantities display to 2 decimal places.

Worked Example: Physics & Engineering Benchmark: VSWR & Return Loss

Convert antenna VSWR into Return Loss (dB) and reflected transmitter watts.

  1. Enter the physical dimensions, electrical parameters, or thermodynamic state variables.
  2. Apply the governing equation: Γ = (VSWR − 1) / (VSWR + 1); ReturnLoss_dB = −20 × log₁₀(Γ); ReflectedPower% = Γ² × 100.
  3. Inspect the primary SI output, derived quantities, and 3 visual SVG graphs.
Result: Computes VSWR & Return Loss via Γ = (VSWR − 1) / (VSWR + 1); ReturnLoss_dB = −20 × log₁₀(Γ); ReflectedPower% = Γ² × 100.

Frequently Asked Questions

What equation powers the Antenna VSWR, Return Loss (dB), Reflection Coefficient & Mismatch Calculator?

It evaluates Γ = (VSWR − 1) / (VSWR + 1); ReturnLoss_dB = −20 × log₁₀(Γ); ReflectedPower% = Γ² × 100 using IEEE-754 double precision and renders three synchronized SVG plots.

Can I test parameter sensitivity across multiple values?

Yes. Graph 1 automatically plots a 50%–150% parameter response curve, and you can pin up to 3 custom scenarios.

Are all units consistent with SI standards?

Yes. Each input field specifies its exact SI or engineering unit and converts internally where needed.

Science & Engineering · Electrical & RF Engineering

Antenna VSWR, Return Loss (dB), Reflection Coefficient & Mismatch Calculator: inputs, method, and how to read the result

Convert antenna VSWR into Return Loss (dB) and reflected transmitter watts.

Choose inputs for the case you are checking

The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.

  • Vswr Ratio: Measured Voltage Standing Wave Ratio (VSWR ≥ 1.0).
  • Forward Transmitter Watts: Forward transmitter RF output power in Watts.

What the calculation includes

With the default values shown, Return Loss (dB) is 13.98 dB. The calculation follows VSWR & Return Loss Physics & Engineering Equation; the formula and variable definitions above show how the inputs combine.

One-input check: With the other defaults held constant, changing Vswr Ratio from 1.5 : 1 to 1.65 : 1 changes Return Loss (dB) from 13.98 dB to 12.21 dB. This is a comparison inside the calculator's stated model, not a prediction.

Where to use caution

  • Uses standard SI physical constants (g = 9.80665 m/s², c = 299,792,458 m/s, σ = 5.670374×10⁻⁸ W·m⁻²·K⁻⁴).
  • Engineering reference model; apply appropriate safety factors and empirical calibration for critical hardware designs.

Scope: SI / NIST Physics & Engineering Standard Check the assumptions and limitations against your situation before relying on the estimate.

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