RF Toolbox

Mismatch Loss

An impedance mismatch reflects some of the incident power back toward the source, so less reaches the load. Mismatch loss is that lost fraction in dB — distinct from return loss, which measures the reflected signal itself. Enter any one of VSWR, reflection coefficient or return loss and get all of them plus the reflected and transmitted power.

Equations & Parameters ▸
\(\Gamma = \dfrac{\text{VSWR}-1}{\text{VSWR}+1},\qquad \text{RL} = -20\log_{10}|\Gamma|\)
\(\text{ML} = -10\log_{10}\!\left(1 - |\Gamma|^2\right),\qquad P_{\text{refl}} = |\Gamma|^2\)
VSWRVoltage standing-wave ratio (≥ 1).
|Γ|Magnitude of the reflection coefficient (0–1).
RLReturn loss (dB) — how far the reflected signal is below the incident.
MLMismatch loss (dB) — the power not delivered to the load because of reflection.
References: D. M. Pozar, Microwave Engineering, 4th ed., Wiley, 2012, §2.3. · Keysight, Understanding VSWR and Return Loss.
Inputs
Pick one
VSWR / |Γ| / RL
Results

Match

VSWR
|Γ|
Return loss

Power

Mismatch loss
Reflected power
Transmitted power
Diagram