Pro Tier Module

RF Cal Lab - VNA Error Correction + Uncertainty

Exact 1-port VNA error correction and a GUM uncertainty budget, computed in your browser.

See it run - a worked example, 100% in this browser tab

The problem

Accredited RF and microwave calibration labs need OSL error correction and a defensible measurement-uncertainty budget that an assessor can reproduce, yet much of that math lives in spreadsheets or instrument firmware no one can audit line by line.

The local-first solution

This plugin computes the textbook 1-port 3-term error correction as an exact complex solve and builds a GUM expanded-uncertainty budget entirely in the browser, with every term traceable to a published reference and no measurement data sent to any cloud.

What it does

Exact 1-port (OSL/SOL) error correction via a 3-term Moebius (directivity, source match, reflection tracking) solve

De-embeds the DUT raw measurement to corrected reflection: |Gamma|, phase, return loss, and VSWR

GUM (JCGM 100) expanded-uncertainty budget combining residual directivity, source match, tracking, noise, connector repeatability, and drift

Mismatch uncertainty limits for a through/power measurement against a source of known match

Published cal-kit library (e.g. Keysight 85033E 3.5 mm) plus custom offset delay/loss and C0-C3 / L0-L3 standard coefficients

Numerical trust verdict from the residual of re-applying the solved error terms to the three standards

Honest scope

The solve and the GUM budget are computed exactly in-browser, and the trust verdict reports only the numerical fidelity of the OSL solve, not a physics validation against an external reference. This is a QA and documentation companion to a calibrated VNA and traceable standards, not a replacement; with the ideal-standards model results are exact only to the extent the kit is ideal, and a mismatched-offset model remains a future increment.

Authorities cited

Rytting, D. K. Network Analyzer Error Models and Calibration Methods. Keysight (Agilent/HP) technical paper. The 1-port 3-term (directivity, source match, reflection tracking) error model and OSL correction.
Keysight Technologies. Specifying Calibration Standards and Kits for Keysight Vector Network Analyzers. App Note 5989-4840EN. Cal-kit standard definitions (offset delay, C0-C3 fringing capacitance, L0-L3 inductance).
JCGM 100:2008 (GUM). Evaluation of measurement data - Guide to the expression of uncertainty in measurement. Combined standard uncertainty by RSS; expanded uncertainty U = k*uc.
ISO/IEC 17025:2017. General requirements for the competence of testing and calibration laboratories. Measurement uncertainty must be evaluated and reported.
Harris, I. A. & Warner, F. L. (1981). Re-examination of mismatch uncertainty when measuring microwave power and attenuation. IEE Proc. H 128(1), 35-41. Mismatch limits +/- 20 log10(1 +/- |Gs||Gl|).
Keysight Technologies. 85033E 3.5 mm Calibration Kit User and Service Guide (doc 9018-01293). Standard definitions for the DC-9 GHz 3.5 mm SOLT kit.
scikit-rf project. SOLT Calibration Standards Creation - tabulated 85033E definitions (open C0-C3, short L0-L3, offset delay/loss), sourced from the Keysight kit definition. https://scikit-rf.readthedocs.io

Run a cal in your browser

Correct a measurement and generate the uncertainty budget client-side, then route the result into a Sandbox workspace, a Worklog case, or a Gate client portal. Nothing is uploaded to anyone's cloud.

Try it live inside GDBS Open a free Standard account

GDBS by VaultSync Solutions Inc. - Verifiable Computation. gdbs.getvaultsync.com