RF Front-End Design Calculator (Gain + NF + IIP3)

Enter per-stage gain, noise figure, and IIP3. The widget computes overall NF, gain, IIP3/OIP3 and per-stage contributions.

Stages (leave unused rows blank)

Stage	Gain (dB)	NF (dB)	IIP3 (dBm)
1
2
3
4
5
6

For each used stage, fill all three: Gain, NF and IIP3. Blank rows are ignored.

Result will appear here.

Total gain

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Overall NF

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Noise factor F

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Te @ 290 K

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Overall IIP3

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Overall OIP3

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Per-Stage Contributions & Design Insights

Relative contribution of each stage:

Stage	Gain (dB)	NF (dB)	IIP3 (dBm)	NF contribution (%)	IP3 contribution (%)

Noise figure (Friis) – linear form:

F_total = F₁ + (F₂ − 1)/G₁ + (F₃ − 1)/(G₁G₂) + …

Cascade IIP3 (input-referred):

1/IIP3_tot = 1/IIP3₁ + G₁/IIP3₂ + G₁G₂/IIP3₃ + …

OIP3_tot (dBm) = IIP3_tot (dBm) + G_total (dB)

First-stage gain and NF largely control system sensitivity, while both gain placement and IIP3 of early stages determine overall linearity. Losses before the LNA degrade NF and IIP3; adding attenuation before a non-linear stage improves IIP3 but costs sensitivity.