A simple utility tool for evaluating S-parameter (Touchstone) file quality based on IEEE 370 standard. SQualCheck provides both GUI and CLI interfaces to assess passivity, reciprocity, and causality metrics in frequency and time domains.
Based on IEEE 370 code, re-implemented in Python using AI coders.
**This code and repo is intended to be a learning experience. The results are correlated to the original code. Use discretion and caution when using. **
-
Comprehensive S-parameter Analysis
- Passivity verification (|S| ≤ 1)
- Reciprocity check (S_ij = S_ji)
- Causality evaluation using Kramers-Kronig relations
- Python implementaion of IEEE370 code -- correlation report here
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Dual Domain Analysis
- Frequency domain metrics
- Time domain validation
-
Multiple Interfaces
- User-friendly GUI with drag-and-drop support
- Command-line interface for automation
- Windows "Open with" integration
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Rich Output Formats
- CSV export for data processing
- Markdown reports with color-coded quality indicators
- Clipboard support for Excel/PowerPoint integration
| Level | Symbol | Passivity (PQMi) | Reciprocity (RQMi) | Causality (CQMi) | Description |
|---|---|---|---|---|---|
| 🟢 Good | ✓ | (99.9, 100] | (99.9, 100] | (80, 100] | Excellent quality, suitable for critical applications |
| 🔵 Acceptable | ○ | (99, 99.9] | (99, 99.9] | (50, 80] | OK quality, may not be suitable for sensitive applications like de-embedding |
| 🟡 Inconclusive | △ | (80, 99] | (80, 99] | (20, 50] | Marginal quality, unlikely to be reliable |
| 🔴 POOR | ✗ | [0, 80] | [0, 80] | [0, 20] | Poor quality, do not use! Re-measurement (+ VNA recalibration) recommended |
| Level | Symbol | Passivity (PQMa) | Reciprocity (RQMa) | Causality (CQMa) | Description |
|---|---|---|---|---|---|
| 🟢 Good | ✓ | [0 mV, 5 mV) | [0 mV, 5 mV) | [0 mV, 5 mV) | Excellent quality, suitable for critical applications |
| 🔵 Acceptable | ○ | [5 mV, 10 mV) | [5 mV, 10 mV) | [5 mV, 10 mV) | OK quality, may not be suitable for sensitive applications like de-embedding |
| 🟡 Inconclusive | △ | [10 mV, 15 mV) | [10 mV, 15 mV) | [10 mV, 15 mV) | Marginal quality, unlikely to be reliable |
| 🔴 POOR | ✗ | [15 mV, +∞) | [15 mV, +∞) | [15 mV, +∞) | Poor quality, do not use! Re-measurement (+ VNA recalibration) recommended |
Reference:"IEEE Standard for Electrical Characterization of Printed Circuit Board and Related Interconnects at Frequencies up to 50 GHz," in IEEE Std 370-2020 , vol., no., pp.1-147, 8 Jan. 2021, doi: 10.1109/IEEESTD.2021.9316329.
# Clone the repository
git clone https://github.com/Sparamix/SQualCheck.git
cd SQualCheck
# Create virtual environment (recommended)
python -m venv venv
source venv/bin/activate # On Windows: venv\Scripts\activate
# Install dependencies
pip install -r requirements.txt
# Run the application
python squalcheck.pyLaunch the graphical interface:
# Using executable
SQualCheck.exe
# From source
python squalcheck.pyGUI Features:
- Load SNP Files: Click to select one or multiple S-parameter files
- Load Folder: Process all S-parameter files in a directory
- Calculate: Analyze loaded files and display results
- Copy Table: Copy results to clipboard for Excel/PowerPoint
- Export: Save results as CSV or Markdown
Process files from command line:
# Basic usage
squalcheck --cli -i input_files.csv
# With custom output prefix
squalcheck --cli -i input_files.csv -o my_results
# Process specific files directly
squalcheck --cli file1.s2p file2.s4p file3.s8p
# To run on examplef files included in the repo
python3 squalcheck.py --cli -i ./example_touchstone/example_list.csv -o test
# To run same, but only FREQ domain (initial) metrics
python3 squalcheck.py --cli --freq-only -i ./example_touchstone/example_list.csv -o testInput CSV Format:
path/to/file1.s2p
path/to/file2.s4p
path/to/file3.s8pOutput Files:
{prefix}_result.csv- Numerical results{prefix}_result.md- Formatted report with quality indicators
numpy- Numerical computationspandas- Data manipulationscipy- Signal processingscikit-rf- S-parameter file handlingtkinter- GUI framework (included with Python)tkinterdnd2- Drag-and-drop support for the GUI (optional; GUI still works without it)
Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.
- Fork the repository
- Create your feature branch (
git checkout -b feature/AmazingFeature) - Commit your changes (
git commit -m 'Add some AmazingFeature') - Push to the branch (
git push origin feature/AmazingFeature) - Open a Pull Request
- scikit-rf - RF/Microwave engineering toolkit
- IEEE 370 MATLAB Repository - Reference implementation
- Simbeor - Commercial S-parameter analysis
- Keysight PLTS - Physical layer test system
This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.
- IEEE P370 Working Group for quality metric standards
- scikit-rf developers for the excellent S-parameter library
- Contributors and testers from the signal integrity community
- Author: Giorgi Maghlakelidze
- Email: giorgi.snp [@] pm [DOT] me
- LinkedIn: my LinkedIn profile
- Bugs & Feature Requests: GitHub Issues
Note: This tool is intended for educational use. While we strive for accuracy, please always validate critical results with established professional tools.
Made with ❤️ for the Signal Integrity Community