SignalIntegrity moves to Nubis Communications

This release is the first release since SignalIntegrity was moved to Nubis Communications. Signal Integrity is now a Nubis Communications supported open-source tool.

Bug Fixes

Test Fixes

Previously, the unit tests could fail based on the order they were run. This was a frustrating problem that existed for quite a long time. This problem has now been fixed.

Zero Length RLGC Transmission Lines

These now work properly and don't cause an error.

Dramatic Speedup for Port Reordering

Port reordering now runs much faster due to lack of extensive copying.

Variables with Spaces

Variables values can now have spaces (mostly for strings) and are now handled properly by enclosing the strings in quotes.

Features

Logarithmically Spaced Frequency Points

During some PDN analysis work, it became painfully obvious that the low frequency aspects dictate very small frequency resolution and therefore lots of frequency points to perform the simulation. An attempt was made to mitigate this by introducing solutions that are made on logarithmically spaced frequency points (a much smaller number of points) and then resampling them at the end onto a linear frequency scale for convolution in simulations. This didn't work perfectly (and it still doesn't), but the feature is added (experimentally). You can try this out by setting the preference that allows this in the projects.

Reference Impedance for Solutions

Previously, all solutions were performed in a 50 ohm reference impedance. Any devices read in, were converted to 50 ohms. If the desire was to have a result in a different reference impedance, this could always be accomplished by post processing, converting the result to whatever reference impedance was desired. Now, the user has the capability to specify the reference impedance to perform the solution at. All devices are converted to the user specified reference impedance for the solution.

Parallel Devices

A new two-port device was added that calculates a device that is the equivalent of a defined two-port s-parameter device placed in a parallel arrangement multiple times. This is useful for parallel pins on connectors, parallel wire bonds, and parallel bypass capacitors -- it greatly simplifies these calculations.

Added COM defined Two-port Transmission Line

A device that implements the IEEE COM definition of the transmission lines has been added, which enables the user to build complete COM package models and PCB traces.

Ignore Missing Other Waveforms

Waveforms whose results are read from the disk during simulation can now be ignored if they are missing, allowing the simulation to continue normally.

Added Cache Control for Variables

Some variables, when changed, should not require recalculation of the entire solution. Now, users can declare variables that should not be in the cache definition.