Cascaded Noise Figure Calculator
Calculate three-stage matched cascade noise figure and each stage’s input-referred excess-noise contribution.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Convert all power gains and noise factors from decibels before applying the matched Friis cascade equation.
Ftotal=F1+(F2−1)/G1+(F3−1)/(G1G2); NF=10 log10(Ftotal)
Worked example
20 dB/2 dB first stage, 10 dB/5 dB second and 0 dB/10 dB third give total noise figure about 2.08311255 dB.
Assumptions and input details
Matched, linear, frequency-specific stages with the same conventional reference temperature. Available power gains are used; mismatch, compression, image responses and temperature corrections are excluded.
References: Analog Devices: system noise-figure analysis
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Calculate resistor open-circuit RMS noise, spectral density, short-circuit noise current and matched-load noise power.
Convert power or root-power amplitude ratios to decibels and back. Add independent source levels that share a reference, using logarithmic power addition.
Calculate ideal free-space received power, entered sensitivity margin and midpoint first-Fresnel radius.
Reserved advertising space.