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NXN SOLUTION USING S2P FILES Dialog Box
Description
Measurements of three device pairings can be combined to deduce the behavior of each individual device. By providing three S2P files containing the response measurements for the device pairs, the user can solve for a device's response characteristics (S2P file). Supply a mixer IF path response S2P file to de-embed.
Requirements
The characterization of the device pairs should be in three (3) files using the S2P format, such as:
• Pair_1_2.s2p
• Pair_1_3.s2p
• Pair_2_3.s2p
Use as many points as possible to improve accuracy. The following requirements apply:
• The frequency list of all.s2p files (except the IF Path) must be the same. Interpolation is not available in the NxN extraction process but it is available when de-embedding the resultant file.
• If the device pairs translate frequency (mixers), device 2 must be reciprocal.
• If concerned with phase wrapping, estimate the length (delay) for each of the devices. If not, use zero (0).
Instructions
1. Select the location and filenames of the input device pairs by selecting the Browse button.
• Each button displays a separate file open dialog box named Select S2P File for Device (#+#) where #+# is either 1+2, 1+3, or 2+3.
2. Input the estimated length (delay) for each device.
• Use the Calculator icon to convert from time to distance.
3. Select the appropriate IF Path.
• Note that if the IF Path De-embed selection is De-embed, an IF Path S2P file is needed.
• IF path de-embedding is used when it is desired to remove the effects of any pad/filter assembly that might be used between devices (particularly when they are mixers). Note that the frequency list in the file must be the VNA frequency range (even if physically it is not) so some S2P editing may be needed.
4. Select the appropriate IF Path Sweep Direction as either HI-LO or LO-HI.
• If the devices are frequency converting and the IF is sweeping the opposite direction from the VNA (that is, if the port 1 frequency increases, the IF decreases because of the LO frequency being used), then select the IF Path Sweep Direction as LO-HI.
• If using LO-HI, an internally swapped list for the IF S2P file will be created. If desired, this can be saved to a file using the Create Modified IF button.
• Otherwise, select HI-LO.
5. Select the Solve button to solve for the desired device, saving as a S2P file. This will prompt for a location of where to save the S2P files.
