Search Ctrl K
Home / Tools
THE FEUTEX TOOLKIT

Third-Order Intercept Estimate

Infer an extrapolated output intercept from measured fundamental and IM3 power.

Communications workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
FormulaOIP3=Ptone+(Ptone−PIM3)/2
Sources and model references

Worked example

Inputs

Each output tone
0 dBm
IM3 spur
-60 dBm
Small-signal gain
10 dB

Expected results

Output intercept
30 dBm
Input intercept
20 dBm

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter the labeled inputs in the indicated units.
  2. Calculate and compare every output against the stated model assumptions.

Try this example

{
  "tone": 0,
  "spur": -60,
  "gain": 10
}

Accuracy and scope

Two equal tones in the cubic small-signal region; intercept is an extrapolation, not deliverable power. Simplified analytical model; not a design recommendation or safety certification.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.