Sceptre has four different output format options. They are: S1, S2, IR, and OR. You must use one of them in the PRI line of every .CKT file.

For best results, Windows Users, running Sceptre in a DOS window, should keep the number of analysis frequencies to (say) 10 maximum.

We have been told that the following URL contains links about console/screen capture utilities that may be of value to some Windows Users. We cannot vouch for them, as we've not tried them. Use them at your own risk:



    S1 Output Format

The S1 option is used in the form PRI AA S1 50. It tells Sceptre to print the s-parameters of two-port "AA" referenced to a 50 ohm system. Run the example file AMPS1 to see it in use.

If the .CKT file contains an active element, i.e., a "TWO," Sceptre will print the stability factor K and its related parameter, B1. If the .CKT file is passive, the printing of stability information will be suppressed.


    S2 Output Format

The S2 option is used in the form PRI AA S2 50. It does the same thing as S1, except it adds the location of input and output plane stability circles. Run the example file AMPS2 to see how it works.

Knowledge of stability circle location helps you to design amplifiers for the case where K, the stability factor, is < 1.

Note: When using the S2 option, the data output to the screen doubles. This may cause, depending on the number of analysis frequencies, screen overflow when running Sceptre in a DOS window. So, when this option is used, the program will pause after printing the initial circuit analysis data. When you "Press any Key" to continue, the remaining stability circle data will be output to the screen.

For more information on K, B1, and stability circles, see Appendix D, and the book by Guillermo Gonzalez, listed as Reference 4, in Appendix G. If you click on a link to visit these appendices, please remember to use the BACK button on your browser to return here.


    IR Output Format

The IR option is used in the form PRI AA IR 50. It tells Sceptre to print the input reflection coefficient magnitude and angle, the VSWR in a 50 ohm system, the return loss (R.L.), and the series impedance equivalent of S11 in two-port "AA." Run example file AMPIR to see how it works.

If the return loss is actually a loss, such as you would expect in an amplifier with good VSWR, its sign will be negative. If, on the other hand, the device input impedance has a negative real part, such as in an oscillator, its sign will be positive.

This option will also allow you to create a .IMP file for use by our SmithMatch program.


    OR Output Format

The OR option is used in the form PRI AA OR 50, and is the same as IR, except it works with S22, the output reflection coefficient.