Qucs-S — The Complete Guide: Analogue and RF Circuit Simulation With a Friendly Schematic Interface
Qucs-S is an open-source graphical front end for circuit simulation. It keeps the friendly Qucs schematic editor but runs the calculation on proven engines — ngspice, Xyce or the original Qucs RF engine — whichever you choose.
Qucs-S
Qucs-S Project
Circuit simulation with a graphical schematic front end over SPICE engines.
Get it from the vendorWhat you get
- Analyses — operating point, DC, AC, transient, noise and S-parameters.
- Swappable engines — the same schematic runs on different engines, for comparison and cross-checking.
- Plots and charts — Cartesian, Smith chart and polar diagrams, placed in the schematic.
- Manufacturer models — loading SPICE models and subcircuits.
- Design helpers — filter, transmission line and matching network tools.
When to choose it
Qucs-S suits anyone who wants a tidy graphical interface for analogue and RF work without writing netlists, and people who work on Linux. LTspice is faster for switching power supplies and ships with a rich component library, but it is not open source. If you already lay out boards in KiCad, you can run ngspice directly there.
Related tools
The most common engine behind it — ngspice. For very large circuits and parallel computing — Xyce. For the printed circuit board — KiCad.
Ngspice
Ngspice Project
Open-source SPICE simulator — DC, AC, transient and noise. The engine behind KiCad simulation.
Get it from the vendor
Xyce — Parallel Analog Circuit Simulator
Sandia National Laboratories
Sandia National Laboratories’ SPICE simulator, built for very large circuits and parallel execution.
Get it from the vendorLTspice
Analog Devices
Fast SPICE simulator with no component limit, unusually strong on switching converters and power circuits.
Get it from the vendor
KiCad
KiCad Development Team
Open-source PCB design suite, from schematic to fabrication files, with no limit on layers or board area.
Get it from the vendorThe bottom line
Qucs-S puts a pleasant interface on top of serious simulation engines. Completely free, and available for Windows and Linux.