When you choose "(3) Calculations" from the Main Menu, either by pressing "3," or by using the "F3" function key, you'll enter the Spline Fit Module. The screen display will look as follows:

       Calculations Module

       Enter Filename [<Enter>=Quit] ? _

Let's look at the file content summary of a bipolar transistor data file that was placed in the mwsoft\sdata\mwdata6 sub-directory during the installation.

At the prompt above, type "NE02135A" and press <Enter>. Here is, except for the color, what you will see:

File: NE02135A        This file contains 9 lines of s-data and 7 lines of n-data.        Perform 'S' or 'N' Calculations (S/N) [<Enter>=Quit] ? _

Be careful above. You must make a conscious choice and choose either "S" or "N." If you accidentally press <Enter> you'll be back at the Calculations Module opening prompt.


Gain/Stability Data

In this instance, type "S" and then press <Enter>. Here is what you'll see:

Gain/Stability Data in a 50 Ohm System Note: GT Max (dB) only defined for K>=1 File: NE02135A    Freq      K-Factor      B1     GT Max (dB)    MSG (dB)     0.100      0.023       0.220                               28.395     0.500      0.368       1.057                               19.530     1.000      0.664       1.288                               16.500     1.500      0.890       1.318                               14.393     2.000      0.960       1.324                               12.430     2.500      1.075       1.338          9.441     3.000      1.125       1.322          8.030     3.500      1.099       1.305          6.974     4.000      1.069       1.297          6.656                                - Press any Key -

Unilateral Assumption

After you "- Press any Key -" as requested above, you'll see the following information about the data just presented, and be offered a suggestion about when you may make a unilateral assumption.

This device is unconditionally stable at  4  frequencies. It has useful gain at  4  frequencies. NOTE: Given that K>=1 and B1 is positive at these points, you MAY, (if S12 is small), make a unilateral assumption and compute the impedance equiv. of S11 and S22. These impedances may then be used to create SmithMatch .IMP load files. Take care to insure stability outside this band. Our Sceptre program will aid you in the calculation of stability circles using the `S2' option.                                - Press any Key -

Here, we are talking about the parameter S12, i.e., the reverse transmission coefficient, as possibly being small, and say that if it is small, S11 and S22 then become fair approximations to the devices in/out impedances. But, how small is small anyway? In general, we've found that is the magnitude of S12 is less than ~ 0.1, the assumption is reasonable.


Sceptre .CKT Files

This time, if you "- Press any Key -" above, you'll see:

Would you like to create a circuit file for use with our Sceptre program         (Y/N) [<Enter>=Quit] ? _

Be careful once again in your response to the above question. If you choose "Y" and press <Enter>, (or just use the "F9" function key), you see the following:

NOTE: All Sceptre files will be directed to the \mwsoft\sceptre\mwdata2                             sub-directory with the .CKT extension.                 Enter Filename [<Enter>=Quit] ? _

Frequency Units

After typing in the filename of your choice, 8 characters max. please, you'll be told:

The data in this file appears to be in terms of GHz. If so, would you like to convert         the data to MHz for use with Sceptre (Y/N) ? _

Since our Sceptre program requires that frequency data be in MHz, you should type "Y" and press <Enter> (or use the "F9" function key). You'll See:

         Data file saved.

If you use SData+ to create files for use with other analysis programs, you might want to leave it in terms of GHz. That is your choice, and now you've seen how to choose.


Unilateral Impedance Data

Then, Yes there's  more, <g> you'll be asked:

         Would you like to see unilateral impedance data
       (Y/N) [<Enter>=Quit] ? _

If you choose "Y" and press <Enter> you'll see:

         Choose S11 or S22 impedance data (11 or 22)[<Enter>=Quit] ? _

Type "11" and press <Enter>. After a question about printing, which Users should ignore by pressing <Enter>, you'll see the following tabulation. This data represents the impedance equivalent of S11 after having made a unilateral assumption for the NE02135A device.

Unilateral device input impedance in a 50 Ohm System File: NE02135A    Freq             Real            Imag   100.000           42.488         -142.513   500.000           11.884          -24.323  1000.000           10.460           -7.152  1500.000           10.609            0.833  2000.000           10.832            7.129  2500.000           10.895           12.354  3000.000           11.465           16.874  3500.000           12.021           22.716  4000.000           12.428           26.949                                - Press any Key -

SmithMatch .IMP Files

Now, if you "- Press any Key -" above, you'll see:

Would you like to create a load impedance file for use with our         SmithMatch program  (Y/N) [<Enter>=Quit] ? _

Note: Please keep in mind when you create a .IMP file for use with SmithMatch, that it cannot have more than 10 lines of data in it!

Be careful again in your response to the above question. If you choose "Y" and press <Enter> you'll see:

NOTE: All SmithMatch files will be directed to the \mwsoft\smithmat\mwdata1 sub-directory  and given the .IMP extension.                 Enter Filename [<Enter>=Quit] ? _

After typing a name, (8 characters or less), you'll see "Data file saved" and be returned to the Calculations Module opening prompt.

We've gone thru a highly detailed scenario working with s-data. We could, (and you can), work thru the same type thing with the noise data in the NE02135A data file.

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To print to either a parallel port, or a USB printer in Windows, from within a program running in a small DOS window, you must first copy the data in the Windows Clipboard. There are two ways to do this:

Method #1:
To print via Windows Paint, Wordpad, or Microsoft Word, from a small DOS window, use the two icons on the left, at the top. First, press 'Mark,' then left-click & drag the white cursor to highlight all the data you wish to transfer to the Clipboard. Now, with the data highlighted, press 'Copy' to paste in to the application of your choice, from which you may print.

Method #2:
To print via Windows Notepad, press the 4th icon from the left, at the top of the small DOS window, marked 'Full screen.' Now, press 'Alt + Print Scrn' to transfer the data to the clipboard. To return to the original small DOS window, press 'Alt + Enter.' Open Windows Notepad, press 'Edit' and then 'Paste.' Now you can print.