Enter your Characteristic Impedance (Z₀) and Load Impedance — split into its Real Part (R) and Imaginary Part (X) — and the Reflection Coefficient Calculator works out your Reflection Coefficient Magnitude |Γ|, along with Phase, VSWR, and Return Loss, so you can see exactly how much signal is bouncing back from your load.
Reflection Coefficient Magnitude |Γ|
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Reflection Coefficient Phase
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VSWR
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Return Loss
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The reflection coefficient (Γ) is the ratio of the reflected wave amplitude to the incident wave amplitude at a point of impedance discontinuity. It ranges from -1 to +1 and indicates how much of the signal is reflected back.
VSWR (Voltage Standing Wave Ratio) is calculated as (1 + |Γ|) / (1 - |Γ|). A perfect match has Γ = 0 and VSWR = 1, while complete reflection has |Γ| = 1 and VSWR = ∞.
Return loss is the negative of the reflection coefficient expressed in decibels: RL = -20 × log₁₀(|Γ|). Higher return loss values indicate better impedance matching and less reflected power.
50 ohms is a standard characteristic impedance that provides a good balance between power handling capability and signal loss for coaxial cables and RF systems.
When ZL = Z₀, there is perfect impedance matching. The reflection coefficient equals zero, VSWR equals 1, and return loss approaches infinity - meaning no power is reflected.
The phase angle indicates the phase shift of the reflected wave relative to the incident wave. It depends on both the magnitude and nature (capacitive or inductive) of the impedance mismatch.
Generally, VSWR < 2:1 is considered good (return loss > 9.5 dB), while VSWR < 1.5:1 is excellent (return loss > 14 dB). The acceptable level depends on the specific application requirements.