VNA calibration is performed to correct for the systematic imperfections which existing in all network analyzers and allow for users to shift the reference plane from the instrument test ports to a user-defined reference plane. However, how can one be sure that the calibration performed will result in accurate measurements?
Validation is by far the most important step in a measurement process. Conventional validation techniques rely on an estimate of the residual errors after a calibration, source match, directivity and tracking, and are typically evaluated by measuring peak-to-peak ripple through a TDR method. These techniques rely on an airline as the validation standard, and the accuracy of the validation can be severely impacted by how well the airline has been machined and handled.
Maury’s new line of Verification Kits allows for a more thorough and definitive validation.
S parameters comparison of User-Characterized and Factory-Characterized Verification Standards
This method involves a user measuring pre-characterized verification devices with similar performances to their own device; i.e. using a short as a validation of a high-reflection single-port device, or an airline for well-matched low-loss devices. The measurement data is then compared to the factory-measured data and the user determines whether the calibration is valid or not, based on experience or general guidelines. There is no clear pass-fail criteria that quantifies whether a calibration is sufficiently accurate to proceed to device measurement, or whether a calibration needs to be repeated.
S-parameters Comparison of User-Characterized and Factory-Characterized Verification Standards including Measured Uncertainty Boundaries
It is possible to define clear pass-fail criteria based on the use of uncertainty boundaries. When the uncertainty boundaries measured on a verification device by the user overlaps the uncertainty boundaries measured on the same verification device at the factory, it is defined as an accurate calibration. If the boundaries do not overlap, then recalibration is recommended. Maury offers a VNA Calibration and Measurement software suite, Insight, which among other things automates this process by guiding users through the calibration validation and clearly identifies whether the calibration can be used or must be repeated. For more information on Insight, please visit maurymw.com.
Kits & Components
Components Included in CK60 Kits
Maury Verification Kits consist of the following verification standards and allow for 1-port and 2-port calibration validation for well-matched and mismatched DUTs:
Beaded mismatch airline
Offset short (female)
Offset short (male)
Fixed Load (female)
Fixed Load (male)
Frequency Range (GHz)
VNA Calibration Kits Kits are the available in many common coaxial and waveguide sizes. Coaxial cal kits are available as Fixed-Load SOLT kits using polynomial equations, and as characterized device (CD) kits using individually characterized cal standards. More information regarding VNA Calibration 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.