Qucs, briefly for Quite Universal Circuit Simulator, is a circuit simulator with graphical user interface (GUI). The GUI is based on Qt® by Trolltech®. The software aims to support all kinds of circuit simulation types, e.g. DC, AC, S-parameter, Harmonic Balance analysis, noise analysis, etc.
Qucsator, the simulation backend, is a command line circuit simulator. It takes a network list in a certain format as input and outputs a Qucs dataset. It has been programmed for usage in the Qucs project but may also be used by other applications. So far we were working on the GUI and on some basic simulation features. In fact there is now a kind of useful user interface for setting up schematics and presenting simulation results in various types of diagrams. DC, AC, S-parameter, noise and transient analysis is possible, mathematical equations and use of a subcircuit hierarchy are available. Anyway, a lot of work has to be done and thus we are looking for people who want to support the project.
In the analogue simulation core global nodes (e.g. subst!) have been introduced, property references inside the same instance of a component and variables in constant parameter simulation boxes are allowed. A noise figure property has been added to the amplifier model and the matrix power operation is available in the equation solver. The Qucs-Converter command line tool allows now to translate existing HICUM models into library elements as well as the translation of polynomial C's and L's and F, H, E and G polynomial SPICE sources.