Thru-Reflect-Line Method

To implement the Thru-Reflect-Line method (TRL), select Tools > Calibration Wizard to open the wizard window. Then select "Thru-Reflect-Line" on the Type drop-down menu. The “Thru-Reflect-Line” calibration method removes the effect of the probe fixtures from a device under test. Probe 1 and probe 2 are not assumed to identical.

The required input is:

1. Two Touchstone files (*.s2p), each of a thru-line of a given length plus the probe fixtures. The lines must be of different lengths.
2. For each port users can specify either a single-ended (*.s1p) or a combined measurement (*.s2p) file. When a *.s2p file is specified, Port 1 uses the S11 values and Port2 uses the S22 values:

• For a short or matched measurement, the surplus inductance needs to be specified.
• For an open circuit reflection, the excess capacitance needs to be specified.
• If no value is given, an ideal reflect is assumed.

3. The imported Zo uses Touchstone file (*.s2p) of an ideal line with no fixture effects. This Touchstone file may come from measurement or simulation. If no file is specified, the wizard approximates the Zo.
4. A Touchstone file (*.s2p) of the chosen device under test with fixture effects.

The output is:

• Touchstone files for the fixtures corresponding to Port1 and Port2.
• A Touchstone file of the device under test with effect of the fixtures removed.
• If "Export Zo" is selected, the frequency dependent Zo of the calibration lines are written to the designated file.