This program defines the VNA calibration parameters and standards, it is used to:
Define the calibration variables.
Define the calibration life.
Define cal standards and parameters.
Operation:
Once editing is complete, the “Save” button stores the changes to the selected report, “Save As New” creates a new DB record with the edited changes and “Cancel” aborts all changes.
Editing:
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Calibration “Calibration” is the user-defined name for the calibration. For VNA measurements, “X mapping” and “Y mapping” will always be frequency and magnitude respectively (though these fields are currently not used with the VNA code, since by having been assigned to VNA measurement, is a given). |
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Standards Currently, available standards are open (response=(1.0 + i0)), short (response=(-1.0 + i0)), load (response=(0.0 + i0)), and short w/offset (response=-e^i*(length/wavelength)). 3 different standards are required for a 1-port VNA measurement though the editor doesn't enforce this requirement. Coax shorts are the default with “length” being the electrical length in inches (presuming no dielectric loading) while waveguide offset shorts must be defined as in the example to the right, all units in inches. “Start X” and “Stop X” should be the valid frequency range (though currently not used). Notes: Waveguide opens should not be used and waveguide offset short responses are calculated from dimensions. There is no provision for supplying a known response but the enterprising engineer may store the error terms for a particular test setup directly into the database. The most accurate calibration for waveguide will be 2 offset shorts and load or 3 offset shorts. Exceeding 3 standards will not work with a 1-port cal. When TRL becomes available, exceeding 3 standards shall improve calibration accuracy. |
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