Process · Analog, RF & Mixed-Signal
De-embedding
Removing the measured effect of test fixtures, probes, pads and boards from RF measurements, so that the results describe the device itself and can be compared with simulation.
- Also known as
- Fixture de-embedding, Fixture removal
- Type
- Process
- Domain
- Analog, RF & Mixed-Signal, RF characterisation
Overview
At radio and microwave frequencies the path between an instrument and the device under test changes what is measured. De-embedding uses a model or measurement of that path to take its effect out of the result, leaving the behaviour of the device alone at a defined reference plane.
How it works
First the instrument is calibrated, which moves the measurement reference to the end of the cables or probes. Everything beyond that point, such as probe pads, access lines, a test board or a socket, is still in the measurement.
To remove it, the team measures dedicated structures that contain only the unwanted parts, for example open, short and through structures built next to the device on the same wafer or board. Their S-parameters describe the fixture as a network, and the measured result is mathematically corrected to strip that network out.
The quality of the result depends on how well the structures represent the real fixture, on the frequency range, and on repeatable probing. Results are checked by de-embedding known reference devices and by comparing with electromagnetic simulation of the fixture.
Examples
- Removing probe pad effects from on-wafer transistor measurements before fitting a device model.
- Correcting amplifier measurements for the loss of an evaluation board.
- Using open and short structures beside an inductor to measure the inductor alone.
- Correlating a production test socket with de-embedded bench data.
Why it matters
Without de-embedding, a part can look better or worse than it is, and the comparison of silicon with simulation that decides whether device models can be trusted becomes unreliable. Characterisation, device modelling and test engineers rely on it from first silicon onwards, and production test limits are correlated back to de-embedded bench results.
It matters most to: Device Modeling Engineer, Electrical Characterization Engineer, Lab Validation Engineer, RF & Mixed-Signal Test Engineer
Common confusions
- Not the same as Calibration
- Calibration corrects the instrument and its cables up to a reference plane using known standards; de-embedding removes the remaining fixture beyond that plane, using structures or models of the fixture itself.
Sources
- IEEE 370-2020: Standard for Electrical Characterization of Printed Circuit Board and Related Interconnects at Frequencies up to 50 GHz (opens in a new tab), IEEE Standards Association, 2026-11-10
- Applications of Calibration Comparison in On-wafer Measurement (opens in a new tab), National Institute of Standards and Technology (NIST), 2026-11-10
- Extending the Open-Short de-embedding frequency via metal-l on-wafer calibration approaches (ARFTG 2022) (opens in a new tab), Delft University of Technology, 2026-11-10
Related terms
Part of the Analog, RF & Mixed-Signal glossary, with every term in the topic and the lifecycles, tools and standards that use them.
Where it appears on the Hub
Used on 13 pages of the Hub. In each group, the pages that mention it most come first.
Lifecycle stages and gates
Skills
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Last reviewed . Written by The Semiconductor Hub editorial team. The full glossary