Two-Line Method

To implement the Two-Line Method, select Tools > Calibration Wizard to open the wizard window. Then select “Two-line method” on the Type drop-down menu. The “two line” calibration method removes the effect of the probe fixtures from a device under test and assumes the effect of fixture 1 is identical to fixture 2.

Note:

The two line method assumes the probe discontinuity can be represented as a simple shunt element. A larger probe will generate proportionally larger errors in calibration. Tolerance is at user discretion.

Note:

There can be only one propagating mode on the transmission line. If there are multiple propogating modes, then calibration may fail.

The required input is:

Two Touchstone files (*.s2p), each of a thru-line of a given length plus the probe fixtures. The lines must be of different lengths.
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.
A Touchstone file (*.s2p) of the chosen device under test with fixture effects.

The output is:

A Touchstone file of the fixture.
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.