Imperfections exist in even the finest test equipment. If uncorrected these systematic imperfections cause the equipment to yield less accurate measurements. The basis of network analyzer error correction is referred to as “calibration” of which multiple methods exist.
8850-Series (50 ohm)
Maury Type N calibration kits are designed for making error-corrected measurements on a wide range of vector network analyzers using precision 50ohm Type N connectors from DC to 18.0 GHz. Each kit includes a full complement of calibration standards and is available with optional in-series adapters. 8850-Series cal kits are available in standard Fixed Load SOLT using polynomial definition and Characterized Device (CD) Fixed Load SOLT using individually characterized calibration standards. Calibration kit coefficient files for modern VNAs and support documentation can be downloaded here.
Fixed-Load SOLT: Polynomial vs Characterized Device (CD)
SOLT calibration requires accurate knowledge of the behavior of the standards; SOLT calibration is only as accurate as the definition of standards used. In practice, the standards are defined by a third degree polynomial function obtained by curve fitting technique which approximates the true behavior of the SHORT, OPEN and THRU standards. When the SOLT calibration is done using polynomial definition of standards, it is called Polynomial SOLT.
The reflection coefficient of the LOAD is taken to be equal to 0 at all frequencies, therefore the minimum discernable return loss is equal to that of the LOAD used for Polynomial SOLT calibration.
When each standard of the SOLT kit is individually and accurately characterized, the calibration is called Characterized SOLT. Each standard has its S-parameters measured at the factory, and unique coefficient files are used by each calibration kit during VNA calibration. Because each standard is individually characterized and no approximate models or assumption are used in this technique, the accuracy of calibration is enhanced.
Verification Kits are designed for 1-port and 2-port VNA calibration validation for well-matched and mismatched DUTs using the following methods: S parameters comparison of User-Characterized and Factory-Characterized Verification Standards; S-parameters Comparison of User-Characterized and Factory-Characterized Verification Standards including Measured Uncertainty Boundaries. More information regarding Verification Kits can be found here.
Insight Calibration and Measurement Software is the the industry’s first commercial software suite designed to empower VNA users and help them make better decisions. Insight represents a paradigm shift in the way users approach VNA calibration, validation, measurement, visualization and analysis. More information regarding Insight can be found here.
Application Notes and Data Sheets
50ohm Type-N Calibration Kit Data Sheet
Improving Calibration Accuracy and Speed with Characterized Calibration Standards