The coaxial setup dialog for SOLT (and SOLR), full 2-port calibration is shown in below.
TWO PORT CAL SETUP (SOLT/R, COAXIAL) Dialog Box
1. Thru selected allows user entries for length, line impedance, line loss and frequency.
2. Reciprocal selected allows user entry for length.
3. S2P Thru selected provides buttons for loading, viewing, and characterization (to generate S2P files).
4. Checking the Use Generic Anritsu Adapter checkbox will automatically load a default .s2p file for a generic Anritsu adapter. Note that selecting the checkbox disables the Load S2P for Thru and Characterize Thru buttons.
In the coaxial setup dialog, the connector types for both ports are selected as well as the thru details and the type of load to be used. For one port calibrations, only one of the port definitions (unless reflection-only calibrations are being performed for both ports 1 and 2) will be present. For a 1-path 2-port cal, one of the Test Port definition sections will not be shown.
The setup dialog above is for coaxial and non-dispersive line types. For waveguide and microstrip, a few things change:
• Fewer cal kits are factory-defined and more are user-defined
• The media must be part of the definition (cutoff frequency and dielectric constant for waveguide; line width, substrate height, and substrate dielectric constant for microstrip)
• SOLT is not recommended for waveguide due to the difficulty in modeling and open standards
For cal kits loaded from Anritsu cal kit files, the model terms are not editable. When using user-defined cal kits, the model terms can be edited.
The insertion loss of the opens and shorts can be defined. A loss variable is entered in dB/mm (which will be applied against the offset length) and the frequency (fref) at which that loss value applies. For other frequencies, the loss is scaled by sqrt(f/fref). If a 0 reference frequency is entered, the loss value is assumed to be constant with frequency. Sometimes, the loss of reflect standards is expressed as gigaohm/second at 1 GHz.
To convert those values to dB/mm, use this equation:
Equation 3‑1.
Where Z0 is the characteristic impedance (usually 50 ohms). Also, enter 1 GHz for the reference frequency as the scaling is the same.
