Signalintegrity

New Features
Peeling

Previously, impedance peeling was part of the SignalIntegrity.Lib library and could be performed with scripts. Now, you can now use impedance peeling to peel off a portion of a connector launch. This is performed by entering a delay value in the port - when this is done, the amount of time entered is peeled off that port after the s-parameters are calculated.

Unfortunately, getting the s-parameters of the peeled port requires another de-embedding operation where the s-parameteters of the structure form the system, the peeled structure is the known, and the s-parameters peeled off are the unknown - a bit more work, but doable.

RLGC fitting
Again, previously this was doable in the SignalIntegrity.Lib library and could be performed with scripts. Now there is a two port element (in the transmission lines category) that takes a file name (which could be a project) and fits an RLGC transmission line (with skin-effect resistance and loss tangent) and provides these s-parameters.

Also, if you have a two-port s-parameter system (at least one device and exactly two ports), the model can be fitted to an RLGC transmission line model. When you select the RLGC fit, the s-parameters of the system are solved, the model is fitted, and the RLGC two-port transmission line model appears in the clipboard. Pressing the left mouse button in the schematic drops the model down on the canvas with all of the transmission line model parameters filled in.

Excess Inductance and Capacitance
Now, in addition to being able to view the impedance profile, it can be viewed as a plot of excess inductance or capacitance, based on the reference impedance specified.

Post-Processing
The feature in SignalIntegrity of being able to add devices as projects led to a particular requirement in that often, after a calculation, causality or passivity is enforced, or the impulse response limited. This meant that in order to use a project as a device, some means were required for performing these enforcements post calculation in an automatic manner.

To facilitate this, the netlist is augmented with a new keyword 'post' that encapsulates the post-processing to be performed and an s-parameter parser has been created that recognizes these netlist lines. In the application, a dialog has been created to allow the addition of post-processing steps. This is all documented in the help system.

Help System
The help system, which was a bit out-of-date has been completely updated to contain all of the latest features in the software.

Device Help
Along with the revamp of the help system, device help has been added. When placing a part in the schematic and when viewing the part properties, a help button now takes the user to the location in the manual where the part is described.

See [Installation](https://github.com/TeledyneLeCroy/SignalIntegrity/wiki/Installation) for installation instructions.

This is the final code version that is referenced in my upcoming book "S-Parameters for Signal Integrity" to be published in Feb-Mar 2020.

This release does not include a lot of new features and is only meant to synchronize the code and code listings with what is mentioned in the book.

See the [link to the book](https://www.cambridge.org/core/books/sparameters-for-signal-integrity/2FD44B994CD054E4B844B358E8903A09).

Book Copy-editing Release
This release is intended only to synchronize my soon to be published book "S-parameters for Signal Integrity" by Cambridge University Press. It really contains only format changes with no new features added.

This release is a bit overdue, but mostly I'm trying to finish my book - many of the changes in this release surround my book, but a few features and bug fixes were added:
Features
PRBS Waveform improvements
PRBS examples were added along with some bug fixes
Clock waveform
now you can use a clock waveform, which goes well with the PRBS waveforms
Reciprocity enforcement
added this capability to the DUT calculation and s-parameter manipulations.
Preferences - SinX interpolation
whether to use SinX interpolation is now an option in the preferences. (otherwise linear interpolation is used).
Waveform display in frequency domain
now, if you want, you can view simulation results in the frequency domain as either spectral content or spectral density.
About box Python version
I was having so much trouble figuring out whether I was running Python 2 or 3 that I added the Python version to the about box.
Labels on plots
Previously, I was quite presumptuous about what was being displayed in the plot windows. Now, the simulation and s-parameter plots are labeled so people know what they are.

Dialog Entry Improvements
Now, when editing properties on the dialog, pressing enter enters the number but doesn't close the dialog. But the focus is set to the dialog box and pressing enter again then closes it and updates the information. Pressing escape allows you to undo the changes. This is helpful on the s-parameter properties dialog where you want to set a bunch of changes and then invoke the changes when the dialog is closed.

Bug fixes:
31
32
33
wavelet denoised s-parameters
a bug where S21 replaced S12 has been fixed.
SinX interpolation bug
way too much waveform was being trimmed off to account for SinX interpolation. The code now trims the correct amount (which is fairly small).

My Book
My book is now frozen and will go to the publisher for copy-edit. This release is now the release that goes with the book forever.

See [Installation](https://github.com/TeledyneLeCroy/SignalIntegrity/wiki/Installation) for installation instructions.

In this release three major features were added:
PRBS Waveform Generation

* Many pseudo-random polynomials.
* a **SerialDataWaveform** class that generates a waveform given a bit pattern
* a **PseudoRandomWaveform** class that generates pseudo-random bit patterns

SOLR calibration

In the VNA calibrations, it can now accept thru measurements and perform the calibration using the 'unknown-thru' method.

In addition, many improvements were made to VNA calibrations including:

* controlling port numbering on DUT calculations. Now, a four-port calibration can be used to calculate a two port DUT on specified ports.
* a DUT _uncalculation_ was added. This let's you see what the VNA actually measured raw based on a given DUT and the error terms.
* calibrations can now be written and read from files.

S-parameter Viewer

Extensive changes were made to this dialog, most importantly:

* The ability to limit impulse responses and resample s-parameter data by simply editing the properties.
* Locking of zooms to improve navigation.
* Panning is now turned on automatically when s-parameters are viewed.

Some Other Feature Improvements

SystemDescriptionParser

Now accepts lists of already generated s-parameters that can be supplied in scripting applications. Previously, when the parser classes are used, the s-parameters must either come from known elements or files. Now s-parameters already calculated can be associated with netlist elements ahead of time, obviating the need to read them from files.

Bug fixes

* Previously, when SIgnalIntegrityApp was started without a project being read, the screen shrunk annoyingly. This has been fixed and now a blank canvas is shown.
* When errors occur opening projects, it now shows you (instead of doing nothing).
* On new projects, the calculation properties were not properly initialized.
* Dialog behavior is improved in that they are withdrawn while drawing them so things behave snappier.
* Spaces are now allowed in filenames in netlists, but they must be surrounded by single quotes (the GUI application automatically supplies these in this instance).
* and of course, many more unittests have been added.

See [Installation](https://github.com/TeledyneLeCroy/SignalIntegrity/wiki/Installation) for installation instructions.

After many years of work, this is the first public release of this software.

This release does not differ significantly from the last. Only some cleanup and very minor bug fixes were made:

* fix to the undocumented integral and derivative probe display (if you precede a the reference designator of a probe with 'i/', it will integrate the result and if you precede it with 'd/', it will take the derivative of the result.

* fixed some annoying visual artifacts of the tkinter GUI. Mostly these involve the fact that as the windows are drawn or destroyed, you can see the window drawn or deleted slowly. The changes involve withdrawing the windows during these events so things appear nicer.

* setup files and information files were modified to indicate that this software is released to the public and is a stable, production version.