Neutron STEM Lab
Virtual engineering lab

Receiver Gain & Noise Budget

Build and reorder a receiver chain, identify dominant noise contributions, and compare sensitivity with small-signal headroom.

Electrical Engineering / RF & MicrowaveintermediateValidated educational model
Learning mode

Guided laboratory

Use the checklist when you want a structured lab. Explore mode leaves the instruments unrestricted.

Explore a model

Set up your experiment

Read the equations

Start with an example, change one input, then run again. Inactive controls do not apply to the selected model. Results and validation always belong to the last completed run.

Use equivalent noise bandwidth, which need not equal the −3 dB bandwidth.
dBm
Available input signal power for a matched source.
Stage noise figures remain referenced to 290 K.
dB
SNR threshold used to calculate receiver sensitivity.
Receiver stages, from input to output

Passive stages are at 290 K; their noise figure follows their loss. Amplifiers use the entered small-signal specifications.

Up to eight stages. Use Move earlier / later to compare stage order.

Choose an example or use the default settings, then run the experiment.

Keep this experiment

Your setup stays in this browser. A project file preserves SI inputs, display units, receiver stages, and any imported complex network samples.

Changes are saved on this device when the settings are valid.

Measurements

Instrument readings

Total gain
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Recorded from the current model setup; rerun after editing inputs.
Cascade noise figure
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Recorded from the current model setup; rerun after editing inputs.
Input sensitivity
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Recorded from the current model setup; rerun after editing inputs.
Theory

Equations and model

Cascade noise

Convert gain and noise figure from dB to linear power ratios before applying Friis. Contributions after the first stage are divided by preceding gain. A passive loss at 290 K has noise factor equal to its linear loss.

Ftotal=F1+F2−1G1+F3−1G1G2+⋯F_{\mathrm{total}}=F_1+\frac{F_2-1}{G_1}+\frac{F_3-1}{G_1G_2}+\cdotsNF=10log⁡10F,Te=290(F−1)\mathrm{NF}=10\log_{10}F,\qquad T_e=290(F-1)

Sensitivity and model limits

The source temperature and equivalent input noise temperature set the available input noise. Sensitivity adds the required output SNR to the input-referred noise power. The model assumes matched, unilateral linear stages and excludes mixer sideband effects.

Nin,eq=kB(Ts+Te)BN_{\mathrm{in,eq}}=k_B(T_s+T_e)BPmin⁡,dBm=10log⁡10(Nin,eq1 mW)+SNRrequired,dBP_{\min,\mathrm{dBm}}=10\log_{10}\left(\frac{N_{\mathrm{in,eq}}}{1\,\mathrm{mW}}\right)+\mathrm{SNR}_{\mathrm{required,dB}}
Validation

Independent checks

Published reference caseNot run

Check the model against a known numerical benchmark.

Expected
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Simulated
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Error
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Tolerance
0.00001%

Run the experiment to perform this check.

Current model applicabilityNot run

Check current assumptions and report any limitations.

Expected
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Simulated
—
Error
—
Tolerance
0%

Run the experiment to perform this check.

Engineering interpretation

Run the experiment to generate an engineering interpretation.

Assumptions and limitations
Assumptions
  • All calculations run locally; frequencies and lengths are stored in SI units.
  • The selected steady-state ideal or approximate model is appropriate to the engineering question.
  • Each experiment states its reference impedance, sign convention, and omitted effects.
Limitations
  • Model benchmarks validate the implementation, not a particular fabricated device.
  • Plots and sweeps have bounded resolution; inspect raw samples and refine a real measurement when required.
  • Guided completion requires current measurements and passing applicability checks. A warning scenario can still be useful for learning.
Local experiment export

Save your measurements and setup

Exports are generated in your browser. No account or server upload is required.

Settings JSON
Current parameters and instrument controls, including waveform, output enable, scope coupling, timebase, trigger, and cursors when present. Data labs also include the dataset, mappings, exclusions, budget, or propagation setup.
Measurements CSV
Completed instrument readings with labels, units, and descriptions.
Plot PNG
The current canvas-based scope, transient, sweep, or statistics visualization when available.
Summary
Markdown report with objectives, setup, measurements, validation, interpretation, assumptions, and graded guided concept-check results.

Ready to export the current local experiment state.

Learning objectives

What this experiment should establish

  • Run the LNA-first chain.
  • Move the loss.
  • Change bandwidth.
  • Inspect linearity limits.
Check your understanding

Questions to answer from the experiment

  1. Where does a 290 K cable loss usually hurt receiver noise figure most?
  2. How should the Friis cascade equation be evaluated?
  3. What happens to integrated white-noise power when equivalent noise bandwidth doubles?
  4. What does a predicted amplifier output above its P1dB indicate?
Continue learning
RF & Microwave LabContinue with the other five RF experiments.AC Circuits WorkbenchReview phasors, reactance, and sinusoidal steady state.Data & Uncertainty LabAnalyze exported numerical data and measurement uncertainty.

Sources and model review

Reviewed 2026-09-17. The educational model exposes its assumptions and validation; source references do not imply external certification.