The NIST Microwave Uncertainty Framework provides a "drag-and-drop" toolkit for managing the calculation of uncertainties in VNA and other measurements. The framework makes it easy to construct models for calibration standards and automates the calculation of uncertainties with both a conventional linear error-propagation analysis and a Monte-Carlo analysis capable of propagating uncertainties through nonlinear models. The framework includes a Vector-Network-Analyzer (VNA) Uncertainty Calculator for guiding the generation of uncertainties in scattering parameters. The framework also includes a post processor that allows the uncertainties in measured scattering parameters to be propagated to derived measurements, such as transistor gain, power, material parameters, and mismatch-corrected temporal signals.
The StatistiCALTM VNA Calibration Software Package is our newest VNA calibration software package. It accommodates almost all coaxial and on-wafer standards, and enables a "mix and match" philosophy to VNA calibration. The software is based on an algorithm developed at the U.S. National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB) of Germany, which is able to estimate the uncertainty of its own results due to random errors. The algorithm features a high degree of robustness, allowing it to find solutions even with poor initial estimates.
The software combines a decade of experience in statistics and orthogonal distance regression with an easy-to-use user interface. Research at NIST has extended the analysis of uncertainties caused by random errors to include systematic errors in the solution. The uncertainties in the solution are represented by a covariance matrix that relates errors in both the VNA calibration and measurements of the device under test. In addition, the algorithm determines coverage factors based on the different numbers of degrees of freedom associated with various parts of the solution.
To receive a free copy of the software, download the installation file, read the user agreement, and request a password. Please include the statement "I have read and agree to the terms and conditions of the NIST Measurement Software user agreement" in your e-mail.
MultiCalTM was developed by the NIST/Industrial Measurement Consortium. On-wafer measurement software implementing the multiline TRL calibration, LRM with imperfect standards, off-wafer CPW calibrations, calibrations for lossy lines, and the calibration comparison method for accuracy assessment. Download the user's manual. The HTBasic*interpreter runs under DOS*, Win3.1*, Win95*, and some other operating systems. Click here to download an older demo version of HTBasic.*
NISTCal was developed by the NIST/Industrial Measurement Consortium. This software performs most of the most-used functions of MultiCal® in a four-port measurement environment. It supports multi-line TRL calibrations with impedance correction, LRM calibrations with imperfect standards, and calibrations for lossy lines. It is capable of performing orthogonal two-port, three-port, and four-port measurements with in-line on-wafer calibrations and the addition of some inexpensive hardware.
Read the user agreement. Request a password. Please include the statement "I have read and agree to the terms and conditions of the NIST Measurement Software user agreement" in your e-mail. Download the MultiCal user's manual, useful for understanding the functions implemented in NISTCal. Download a paper describing the 4-port hardware and algorithm.
The NIST LSNA Verfication Software uses a procedure similar to the calibration comparison method to help a user evaluate the differences between LSNA calibrations. The user performs two calibrations that may differ due to standards used, test set drift, or other reasons. The software program compares the two calibrations and helps the user asses the impact of the differences between them. Read a paper about the method.
Software designed to accurately determining the characteristic impedance of transmission lines fabricated on silicon substrates. The Characteristic Impedance of Silicon Transmission Lines Software was developed by the NIST/Industrial Measurement Consortium and is only available to Consortium members until May 1999.
Read the user agreement. Request a password. Please include the statement "I have read and agree to the terms and conditions of the NIST Measurement Software user agreement" in your e-mail. Download a paper comparing this algorithm to other methods.
Software for computing causal characteristic-impedance magnitude from the phase of the integral of the Poynting vector over the guide cross section. The resulting characteristic impedance satisfies the requirements of a new causal power-normalized circuit theory.
Read the user agreement. Request a password. Please include the statement "I have read and agree to the terms and conditions of the NIST Measurement Software user agreement" in your e-mail. Download preprint of a paper describing the algorithm.
Software to assist in correctly applying the numerical Fourier Transform. This software package helps in selecting the proper Forier transform formulas and normalization constants. Both single pulses and repeating signals are treated. The progam displays appropriate relationships on the front panel. See the related paper describing terminology for oscilloscope calibrations.
Use VeridiCal to automate VNA verifications with electronic calibration units. Not only does the software streamline the verification process, but it more completely verifies the calibration and allows you to see the impact of the calibration errors on your device under test directly. Read a paper about VeridiCal. This software requires a NIST-calibrated electronic verification artifact and requires signing special use agreements.
Software for time-domain network analysis.
*We use trade names here to assist the user of this web site. It does not imply a recommendation or endorsement by the National Institute of Standards and Technology. StatistiCAL is a trademark of the National Institute of Standards and Technology.
An on-wafer measurement tutorial narrated in Power-Point with embedded references.
Related Programs and Projects:
High Speed Measurement
On-Wafer Measurement Metrology
Metrology for Electronic Packaging