RF-Touchstone

A Javascript/TypeScript library for reading, manipulating, and writing Touchstone files (.snp files) used in radio frequency (RF) and microwave engineering.

Test Status

Node.js	v20	v22	v24
Linux
Windows
macOS

Overview

RF-Touchstone provides a complete solution for working with S-parameters and other network parameters in JavaScript/TypeScript environments. This library allows you to:

• Read and parse Touchstone files (.s1p, .s2p, .s3p, etc.)
• Manipulate network parameter data
• Write data back to Touchstone format
• Convert between different parameter representations (RI, MA, DB)

What is a Touchstone File?

Touchstone files are an industry-standard ASCII text format for representing network parameters of electrical circuits. Each file contains:

• Comments (lines starting with !)
• Option line (starts with #) specifying frequency units, parameter type, and data format
• Network parameter data organized by frequency points

RF-Touchstone currently supports versions 1.0 and 1.1 of the Touchstone specification.

Key Features

• Full support for Touchstone file format (v1.0 and v1.1)
• Parameter type support: S, Y, Z, G, H
• Format conversions: RI (Real/Imaginary), MA (Magnitude/Angle), DB (Decibel/Angle)
• TypeScript implementation with strong typing
• Comprehensive test suite
• Published on NPM: rf-touchstone

Installation

Via NPM/Yarn

npm install rf-touchstone
# or
yarn add rf-touchstone

Via CDN (Browser)

<!-- Using unpkg -->
<script src="https://unpkg.com/rf-touchstone"></script>

<!-- Or using jsDelivr -->
<script src="https://cdn.jsdelivr.net/npm/rf-touchstone"></script>

<script>
  // Access via global variable
  const { Touchstone } = window.Touchstone
</script>

Quick Start

import { Touchstone } from 'rf-touchstone'

// Read from a URL (nports automatically determined from .s2p)
const touchstone = await Touchstone.fromUrl('https://example.com/device.s2p')
console.log(touchstone.name) // 'device' - automatically extracted from filename

// Or from a File object (e.g., from a file input)
const touchstoneFromFile = await Touchstone.fromFile(file)
console.log(touchstoneFromFile.name) // Filename without extension

// Or from a raw text string with optional name
const touchstoneFromText = Touchstone.fromText(fileContent, 2, 'my_measurement')

// Access data
console.log(touchstone.frequency.f_scaled)
console.log(touchstone.matrix)

// The name property is useful for plot legends and default filenames
touchstone.name = 'modified_network' // Can be modified

// Write back to Touchstone format
const newContent = touchstone.writeContent()

Online Demo

Experience the library in action with our Touchstone Converter (React). It allows you to:

• Load local or remote .snp files
• Inspect metadata and network data
• Convert formats and units on the fly
• Download modified Touchstone files

Examples

This repository includes examples to demonstrate the usage of rf-touchstone in different contexts.

• React Example: A complete web application (using Vite and TypeScript) that showcases how to build a Touchstone file viewer/converter. You can try the Live Demo.

Documentation

For detailed documentation, please visit:

• Project Website
• AI Usage Guide - Comprehensive guide for AI coding assistants and developers integrating this library
• DeepWiki Documentation - Interactive AI documentation that allows you to converse and ask questions about this repository
• Changelog

Development

For information on setting up a development environment and contributing to the project, see development.md.

Credits and Acknowledgments

This project uses test data files (e.g., .sNp files) sourced from or generated by scikit-rf.

• scikit-rf License: The test files are used under the terms of the BSD 3-Clause License.
• The original copyright and "Created with skrf (http://scikit-rf.org)" headers in these files have been preserved as required by the license.

We thank the scikit-rf contributors for their excellent work in providing these resources to the RF community. Additionally, we use scikit-rf as a reference to validate our library's parsing and manipulation results, ensuring cross-platform consistency and accuracy.

License

This project is licensed under the MIT License - see the LICENSE file for details.