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Cascaded Noise Figure Calculator

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Noise Figure Calculator - Cascaded Amplifier NF Calculator
Stages
Stage
NF dB
Gain dB
Please enter valid values in all stage fields.
RESULTS
TOTAL NOISE FIGURE
dB
TOTAL GAIN
dB
NOISE TEMPERATURE
K

Cascaded Noise Figure Diagram

Cascaded Noise Figure Calculation Stage 1 NF₁, G₁ Stage 2 NF₂, G₂ Stage 3 NF₃, G₃ ... Output Total NF + Gain Earlier-stage gain reduces the noise impact of later stages

Formulas

Ftotal = F1 + (F2 - 1)/G1 + (F3 - 1)/(G1 × G2) + ...
NFtotal(dB) = 10 × log10(Ftotal)
Total Gain(dB) = G1(dB) + G2(dB) + G3(dB) + ...
Noise Temperature = 290 × (10^(NFtotal/10) - 1)

Diagrams & Theory

Cascaded noise figure is used for RF receiver chains with multiple amplifiers, filters, mixers, or other gain stages.

The first stage is very important because its gain reduces the noise contribution of later stages. This calculator uses the standard Friis cascaded noise figure relation.

Example

Input Example

Stage 1: NF 1.2 dB, Gain 15 dB
Stage 2: NF 3 dB, Gain 10 dB

How to Use

Choose the number of cascaded amplifier stages, enter each stage noise figure and gain in dB, then click calculate.

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About this tool

Cascaded Noise Figure Calculator is a free online calculator tool. Use it to get instant, accurate results for your electronics calculations.