The NxN application is started from the APPLICATION menu as shown in Figure: APPLICATION Menu—NXN Control Button.

Selecting the NxN button will open the main NxN dialog as shown in Figure: NXN SOLUTION USING S2P FILES Dialog Box. The measurements shown in Figure: NxN Technique Measurements or Figure: NxN Measurement Setup (using an inner network N) must first be performed and those measurement results saved as S2P files. The match information in these files will be ignored, but the file format for a full 2-Port measurement is used for convenience. These S2P files are entered in this dialog using the Browse buttons shown.

If the scheme of Figure: NxN Measurement Setup (using an inner network N) is used, then the inner or IF network must be specified. Select IF Path De-embed in this case and use the browse function to locate the S2P file for the IF network. Note that all of these S2P files must have the same number of points and the frequency range of the IF file must be appropriate for the IF sweep range between the devices. If the devices are non-converting, the frequency range of the IF file must match that of the other files.

If the devices are frequency converting, the sweep direction in the inner or IF zone must be specified. If the inner frequency sweeps up for a sweep up in the input frequency, then select LO-HI (non-inverting). Otherwise, select HI-LO.

The computation produces a phase ambiguity when it solves for the devices so some information about the electrical length of the devices should be entered. Boxes are provided for entering the approximate air-equivalent electrical length of each device. The calculator icon can be used if time delay estimates are known instead and a conversion calculator will appear. If the phase shift for the devices is not of interest, these lengths may be left at zero. If they are of interest, the estimate should be accurate to within a half wavelength at the lowest input frequency being used.

Once all of the information is entered, the Solve Device x buttons at the bottom of the dialog (x = 1, 2, or 3) will trigger the computation. Each invocation will bring up a file dialog to name the S2P file describing the device in question. If only the information for one device is needed, only that button need be selected.

If more devices are to be tested in the same configuration (e.g., one has a collection of mixers to measure of the same model), then these devices can be combined, one at a time, with a now known device (1, 2, or 3). Since the S2P file for the now known device has been generated, it can be de-embedded using the standard embedding/de-embedding utility described elsewhere in this measurement guide.