Amplifier & Receiver
Cascaded Noise Figure Calculator
Add the gain and noise figure of each stage to get the total noise figure of a receive chain. Results update as you type.
Result
- Cascaded noise figure
- 1.423dB
- Total gain
- 11dB
- Cascaded noise factor (F)
- 1.388
Share of the total noise factor contributed by each stage
Formula: F_total = F₁ + (F₂ − 1)/G₁ + (F₃ − 1)/(G₁G₂) + …
Gains and noise figures go in as dB and are converted to linear ratios internally. A passive stage such as a filter or a length of cable has a noise figure equal to its loss, so a −2 dB filter is entered as −2 dB gain and 2 dB noise figure.
Because each stage is divided by the gain ahead of it, the first stage dominates. That is the whole argument for putting a low-noise amplifier first and accepting the loss of anything placed before it.
Related: noise figure to noise temperature, minimum detectable signal.