A Python library for Touchstone
.sNpparsing and S‑parameter analysis in RF/microwave engineering.
touchstone.parser is a clean, modular, enterprise-ready Python library for parsing Touchstone (.sNp) files — the industry-standard format for RF and microwave S‑parameter data. It provides strongly typed classes, LINQ-friendly APIs, and seamless integration into simulation and analysis workflows.
- Parse
.sNpfiles into strongly typed Python classes (TouchstoneData,FrequencyPoint,NetworkParameter) - Multi-port support — 1‑port through N‑port networks
- All data formats — Real/Imaginary (RI), Magnitude/Angle (MA), Decibel/Angle (DB)
- All frequency units — Hz, kHz, MHz, GHz with automatic normalization
- All parameter types — S, Y, Z, H, G
- LINQ-friendly APIs — query S‑parameters with
get_s11(data),get_s21(data),data.get_parameter(r, c) - RF calculations — insertion loss, return loss, VSWR out of the box
- Export utilities — CSV export and Touchstone writer for round-trip fidelity
- Minimal dependencies — powered by
numpyfor fast array operations
pip install touchstone.parserOr via the PyPI Package Manager:
pip install touchstone.parser
from touchstone.parser import TouchstoneParser
# Parse a Touchstone file
data = TouchstoneParser.parse("filter.s2p")
print(f"Ports: {data.n_ports}")
print(f"Frequency points: {data.n_freq}")
# Query S21 insertion loss
il = data.to_insertion_loss()
for f, val in zip(data.frequencies, il):
freq_ghz = f / 1e9
print(f"{freq_ghz:.3f} GHz → IL = {val:.2f} dB")
# Filter to a frequency range
passband = data.in_frequency_range(2.0e9, 3.0e9)
# Compute VSWR
vswr = data.to_vswr()
for f, val in zip(data.frequencies, vswr):
print(f"VSWR = {val:.3f}")
# Export to CSV
data.to_csv("output.csv")| Method | Description |
|---|---|
TouchstoneParser.parse(filepath) |
Parse from a file path |
TouchstoneParser.parse_string(content, n_ports?) |
Parse from a raw string |
| Method | Description |
|---|---|
data.get_s(to_port, from_port) |
Get S‑parameters across all frequencies |
data.frequency |
All frequency values in Hz |
data.s_parameters |
3D numpy array of all parameters |
| Method | Description |
|---|---|
data.to_insertion_loss() |
|S21| insertion loss in dB |
data.to_return_loss() |
|S11| return loss in dB |
data.to_vswr() |
VSWR from S11 |
| Method | Description |
|---|---|
data.in_frequency_range(min_hz, max_hz) |
Filter to frequency range |
data.to_csv(writer) |
Export to CSV file or path |
data.to_csv_string() |
Export to CSV string |
write_snp(data, filepath) |
Write back to Touchstone format |
| Method | Description |
|---|---|
normalize_frequency(val, unit) |
Convert to Hz |
db_to_mag(db) |
Convert DB to magnitude |
mag_to_db(mag) |
Convert magnitude to DB |
ma_to_complex(mag, deg) |
Create from MA |
db_to_complex(dB, deg) |
Create from DB |
touchstone-python/
├── src/
│ └── touchstone/parser/ # Core library
│ ├── models/ # Domain models (enums, data classes)
│ ├── parsing/ # Parser engine
│ └── utilities/ # Converters, extensions, writer
├── tests/ # pytest test suite
├── docs/ # Sphinx documentation
├── pyproject.toml # Project metadata and dependencies
└── .github/workflows/ # GitHub Actions CI/CD
| Feature | Supported |
|---|---|
| Touchstone v1.0 / v1.1 | ✅ |
1‑port (.s1p) |
✅ |
2‑port (.s2p) |
✅ |
Multi-port (.s3p, .s4p, ...) |
✅ |
| Real-Imaginary (RI) | ✅ |
| Magnitude-Angle (MA) | ✅ |
| Decibel-Angle (DB) | ✅ |
| Hz / kHz / MHz / GHz | ✅ |
| S / Y / Z / H / G parameters | ✅ |
| Comments and metadata | ✅ |
| Touchstone v2.0 keywords | 🔜 Planned |
pytest --verbosity normalContributions are welcome! Please see CONTRIBUTING.md for guidelines.
- ⭐ Star this repo and related RF/microwave projects to help them grow - then mention your project in context to build visibility.
- 💡 Share feedback via GitHub Discussions - we'd love to hear how you're using the library, what's working, and what could be better.
This project is licensed under the MIT License.
If this library helps you in your RF/microwave engineering work, consider supporting its maintenance and the development of new features:
- Sponsor on GitHub
- ⭐ Star the project to help it gain visibility in the engineering community.
- Touchstone File Format Specification (IBIS)
- S-parameter — Wikipedia
- PyPI Package
- Touchstone .NET Library - check out the .NET version for C#-based workflows.
Made by suryamangaraj · Built for the RF/microwave engineering community 📡
