Noise Figure & Cascade Calculator
Add amplifier or attenuator stages to calculate cascaded noise figure using the Friis formula.
Cascade Stages
| # | NF (dB) | Gain (dB) |
|---|
Results
Total Noise Figure
cascaded (Friis)
—
Equivalent Noise Temperature
T₀ = 290 K reference
—
Formulas
Friis Formula
F = F₁ + (F₂−1)/G₁ + (F₃−1)/(G₁G₂) + …
F = linear noise factor = 10^(NF/10)
NF → Noise Temperature
T = T₀ × (F − 1)
T₀ = 290 K (IEEE standard)
NF (dB) ↔ Linear
F = 10^(NF_dB / 10)
NF_dB = 10 × log₁₀(F)
Stage 1 dominates the cascade. A low-NF, high-gain LNA at the front significantly reduces the noise contribution of subsequent stages.