
S-parameters are one of the most important pieces of information regarding any passive or active component for RF design, simulation, and analysis. To ensure the accuracy and quality of the complex system, RF engineers often deal with S-parameters of many devices and components.
1. AppCad Design Assistant


Supported formats
- Rectangular Plot / Logarithmic magnitude
- Smith Chart
- Polar format
- Smith Chart: Gain/Noise Circle
- Tabular listing (frequency and gain)
- Support multiple files for comparison
- Lumped Balun design and tuning
- Voltage biased circuits
- Current biased circuits
- Small signal and large signal detector
- FET and transistor bias source resistor
- Amplifier efficiency
- Transmission line impedance calculation
- Reflection, Noise, Spurs, and Intercept point calculations
- Device thermal calculations
- Engineering constants and Complex Math calculations for RF circuits
- Print plots and results
- Only support 2 port S-parameters
2. RFSim99

RFSim99 is a powerful tool to simulate and analyze simple circuits and plot S-parameter files. It can simulate one port and two port measurements with basic passive elements, and it is suitable for simple impedance matching and plotting.
- Linear magnitude
- Logarithmic magnitude
- Smith Chart
- Polar format
- Phase
- Group delay
- Simulate 2 port circuits
- Analyze S-parameter
- Impedance matching
- Only support 2 port measurements
3.RSplot

- Logarithmic magnitude
- Phase format
- Delay
- Support multiport S-parameter
- Support multiple files for comparison
- Adjust view
- Adjust Frequency /Span
- Markers and Legends
- Print plots
- Only support rectangular plots
4. SPview
SPview is yet another software tool from ARK RF Systems for plotting and analyzing S-parameter files. This tool comes with full function for the first 30 days, but some of the basic features are available after the evaluation period. It is a simple application with a user-friendly GUI.Supported formats
- Logarithmic magnitude
- Smith chart
- Admittance chart (Y Smith)
- Polar format
- VSWR (only for the full version)
- Group delay (only for the full version)
- Phase (only for full version)


- Support multiport S-parameter files
- Script support for more functions (full version)
- Schematic analysis (only for the full version)
- Remote communicator for instrument connectivity
- Mix mode analysis
Limitation
- Full functions only available with the licensed version
5. QUCS Simulator
Quite Universal Circuit Simulator is another powerful tool to simulate basic electronic circuits and S-parameters. QUCS is free software under GPL (General Public License) available for all operating systems.
QUCS supports Verilog-A compact model standardization for electronic circuit design and macro modeling.
Supported formats
- Linear magnitude
- Logarithmic magnitude
- Smith Chart
- Polar format
- Phase
- Tabular
- Smith – Polar Combination
- 3D-cartesian
Options
- Simulation of electronic circuits with component library and macro modeling
- S-parameter simulation
- DC simulation
- AC simulation
- RF Simulation
- Low Pass, High Pass, and Band Pass filter design
- Impedance matching
6. S-View S-parameter Viewer
S-View is a simple S-parameter viewer; It allows you to plot the S-parameter data, which is used to characterize RF/Microwave components and systems. The S-View supports the touchstone format, which has file extensions such as .s1p, .s2p, .s3p, .s4p etc
Download it from the Microsoft Store: S-view s-parameter viewer
Conclusion
RF system complexity has been increasing, and thus the challenges in design and implementation are also huge. RF engineers use sophisticated tools for design, simulation, and analysis. I hope the above-mentioned software can be used for a better understanding of S-parameters, simple analysis, and as a handy tool for personal use.