Touchstone file
Network parameter data file
title: "Touchstone file" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["electronic-design-automation", "eda-file-formats"] description: "Network parameter data file" topic_path: "general/electronic-design-automation" source: "https://en.wikipedia.org/wiki/Touchstone_file" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Network parameter data file ::
::data[format=table title="Infobox file format"]
| Field | Value |
|---|---|
| name | Touchstone File |
| extension | .s1p, .s2p, .s3p, .s4p, .snp, .ts |
| owner | IBIS Open Forum, Agilent Technologies Inc |
| released | |
| latest release version | 2.1 |
| latest release date | |
| genre | Document file format |
| standard | Touchstone |
| url | IBIS |
| :: |
| name = Touchstone File | icon = | logo sg = | screenshot = | caption = | extension = .s1p, .s2p, .s3p, .s4p, .snp, .ts | mime = | type code = | uniform type = | magic = | owner = IBIS Open Forum, Agilent Technologies Inc | released = | latest release version = 2.1 | latest release date = | genre = Document file format | container for = | contained by = | extended from = | extended to = | standard = Touchstone | url = IBIS}}
A Touchstone file was originally a proprietary file format for the eponymous frequency-domain linear circuit simulator{{cite web | url = http://www.microwaves101.com/encyclopedia/historyCAD.cfm#touchstone | title = History of EEsof and Touchstone at Microwaves 101
The Touchstone simulator has long since been superseded,{{cite web | url = http://www.keysight.com/en/pd-1385381-pn-W2200BP/advanced-design-system-ads-core | title = W2200 Advanced Design System (ADS) Core
A Touchstone file (also known as an SnP file after its set of file extensions) is an ASCII text file used for documenting the n-port network parameter data and noise data of linear active devices, passive filters, passive devices, or interconnect networks. An example of the format of the S-parameter section is given in the article about S-parameters. In addition to S-parameters, other representations such as Y-parameters and Z-parameters can be recorded.
It later became a de facto industry-standard file format not only for circuit simulators but also for measurement equipment (e.g. vector network analyzers, or VNAs), then later still an EIA standard as part of the Input/output Buffer Information Specification (IBIS) project.{{cite web | url = http://www.ibis.org/ | title = IBIS (I/O Buffer Information Specification) | url = http://www.ibis.org/touchstone_ver2.0/touchstone_ver2_0.pdf | title = Touchstone File Format Specification Version 2.0 | format = PDF | url = http://www.ibis.org/connector/touchstone_spec11.pdf | title = Touchstone File Format Specification Rev 1.1 | format = PDF | url = https://ibis.org/touchstone_ver2.1/touchstone_ver2_1.pdf | title = Touchstone File Format Specification Version 2.1 | format = PDF
Several further enhancements to the file format that allow description of the non-linear behavior of the component have been developed under the P2D and S2D pair of formats,{{cite web | url = http://www.keysight.com/en/pd-1385381-pn-W2200BP/advanced-design-system-ads-core | title = E8854A RF System, now part of W2200 Advanced Design System (ADS) Core
Notes
References
- .S1P for one-port (e.g. termination), .S2P for two-port (e.g. transmission line), .S3P for three-port (e.g. a balun), .S4P for four-port (e.g. a differential transmission line) and so on.
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