Frequently Asked Questions

1. What is Atyune?
Atyune is a Windows program that simplifies the design of impedance matching circuits for RF and microwave applications. It is particularly well suited to antenna matching, but works for any matching problem. It is also a useful tool for viewing, manipulating and archiving S-parameter files. You can start the program, load a file and have a matching circuit designed automatically in about three clicks and five seconds, with no projects to set up.

2. Who should use Atyune?
Atyune is aimed at anyone who designs or tunes matching networks: antenna designers, RF engineers, hardware engineers integrating wireless modules, and laboratory technicians who measure and tune boards on a VNA. The interface is simple enough for junior technicians, while advanced features such as power-transfer optimisation, 2-port design, tolerance analysis and TDR serve experienced engineers. Labs and companies also benefit from the shared S-parameter Archive.

3. How do I install Atyune?
Download the installer (setup_Atyune_x64.exe) from the Downloads page and run it, following the on-screen steps. Please read the End User Licence Agreement (EULA) first, because downloading the software implies acceptance of it.

4. What are the system requirements?
Atyune 3.x requires Windows 8.1 or newer. If you are still using Windows 7, please download version 2.5.7, which is also available on the Downloads page.

5. Is a license required?
No licence is needed to get started. The free download is fully functional and includes a usable set of component libraries, free NanoVNA and LibreVNA drivers, and two demo drivers. A licence is only required for two optional extras: the extended component libraries and VNA connectivity beyond the free and demo drivers. These two extras can be licensed separately. Licences are tied to the ID of the computer running Atyune. Any licence issued for version 2.x is automatically valid for version 3.x.

6. Is Atyune free, and does the free version expire?
Yes, the free version can be downloaded at no cost. It carries an expiry date, which ensures users periodically upgrade to the latest release. The intention is to keep Atyune freely available after that date. If you obtain an extended components library or VNA connection license, the expiry date is generally removed.

7. My antivirus flags Atyune as malware. What should I do?
This is a known false positive with some antivirus products. You can check the installer or executable yourself by uploading it to VirusTotal (virustotal.com). Please also report it through the Contact page so it can be looked into.

8. Which file formats can Atyune import?
Atyune's preferred format is Touchstone (.sNp), with any number of ports, frequency units, data formats (DB, MA, RI) and reference impedance. Touchstone 2.0 is supported for S-parameters in full-matrix format. Atyune can also import CITI files (.d1/.d2) from older HP VNAs and, tentatively, ZVCE files (.asc) from older Rohde & Schwarz VNAs. For data prepared in a spreadsheet, a simple, clearly defined 1-port CSV format is supported (see the manual). General VNA CSV exports are not supported, because they often lack the full complex data.

9. Can Atyune read data directly from my VNA?
Yes. Atyune includes a built-in VISA interface, so installation of external VISA libraries, like Keysight or NI, are not required (although they are still supported). Free, fully functional drivers are built in for the NanoVNA family (except the "SAAS" variant) and the LibreVNA. Two demo drivers for common Keysight and Anritsu instruments are included, limited to S11. For other instruments, contact info@atyune.com for a licence and the appropriate driver.

10. Does Atyune use ideal or real components?
Atyune uses real components models. Its libraries model inductors and capacitors based on S-parameter measurements, including each part's tolerance, and you can click any component to see its part number and tolerance. The free version includes generic 0402 and 0603 real-model inductors and capacitors, plus ideal components. Extended libraries cover many series from manufacturers such as Murata, TDK, Coilcraft, Taiyo Yuden, AVX, Samsung, Würth, Kemet, Walsin and Yageo, in sizes from 01005 to 1111. Custom libraries can be created on request.

11. How does Atyune design a matching circuit?
You can draw a circuit in the built-in schematic editor, start from one of 10 predefined common matching topologies, or let Atyune do the work. Auto Matching optimises the component values of your circuit. Find Best Circuit searches for the best topology automatically, typically in a few seconds. You can also tune values manually and freeze components whose values you want to keep fixed.

12. Can I set my own optimisation goals?
Yes. By default, Atyune minimises the reflection coefficient or maximises the power delivered to the load across the selected frequency bands. You don't need any setup for this, and an extensive list of common wireless bands is built in. You can also define your own optimisation targets. Multitrace matching lets you optimise one circuit for several impedance traces at once, for example an antenna in free space, next to the head and in the hand.

13. What is the recommended optimization method for antennas?
For antenna matching, the recommended method is the default one: the desired frequency bands are selected when loading the data, and the optimization is set to “Transmission”, as in this way the power delivered to the antenna is maximized, and not return loss; this set-up is compatible with all circuit design methods (user designed circuit + automatic optimization, Find Best Circuit, Multitrace matching).
Setting explicit optimization targets is better suited for 2-ports circuits.

14. Can Atyune handle 2-port circuits and non-50 Ω systems?
Yes. Atyune can optimise both 1-port and 2-port circuits. You can change the system impedance in Preferences, or use a frequency-dependent port impedance defined by a file. A typical use is matching an antenna to the actual output impedance of an amplifier rather than to 50 Ω.

15. How accurate are Atyune's results?
Atyune gives an excellent starting point, but it does not simulate the PCB layout. Interconnections, grounding paths and pad parasitics are ignored, as is mutual coupling between components, and only cascade networks are simulated. The component models are generally accurate up to about 6–7 GHz. You can reduce layout effects by placing components close together with short ground paths, adding microstrip lines, or using the "Size Approximation" option. In practice, nudging a critical component one value up or down is usually enough to reach the predicted result.

16. Why are my measured results different from Atyune's prediction?
By far the most common cause is poor calibration of the measurement cables or an incorrectly placed reference plane. No simulator can be more accurate than the calibration of its input data. Calibrate carefully and use your VNA's port extension where available. Atyune also provides two dedicated tools to help: Automatic Port Extension and "Find Delay", an electrical delay calibration feature.

17. Can Atyune analyse component tolerances?
Yes. Because the libraries include each component's tolerance, Atyune can run a tolerance analysis on your matching circuit. This shows how manufacturing spread is likely to affect performance before you commit to production.

18. What is the Atyune Archive?
The Archive is a built-in system for storing and finding S-parameter files. Each file is tagged with a project number, user initials, a simulation/measurement flag and a description. You can add files by drag-and-drop and load them back with a double-click. The Archive handles hundreds of thousands of files and keeps a local index cache for speed. Placing it on a shared drive lets a whole lab or company share measurements instantly.

19. Does Atyune support Time Domain Reflectometry (TDR)?
Yes. Enable it from the main menu under TDR → Enable TDR, and a time-domain graph tab appears. TDR helps you locate discontinuities in cables, transmission lines, transitions and connectors. Time gating can remove a discontinuity's effect and transform the data back to the frequency domain. Windowing, zero-padding and exporting of TDR data are also available.

20. How can TDR time gating improve my measurements?
Time gating removes the effect of an unwanted discontinuity from your S-parameters after the measurement. Typical examples are an imperfect coaxial connector or a poor transition between a pigtail cable and a PCB trace. Atyune converts your frequency-domain data to the time | distance domain, where the discontinuity appears as a peak around the position of the problem. After selecting the range of the discontinuity in the time | distance domain, Atyune sets the signal to zero over that range and converts the data back to the frequency domain. The result is a new S-parameter trace that is much closer to the true response of your device.

To use it, enable TDR (TDR → Enable TDR) and transform your data to the time domain. Then right-click an empty area of the time-domain plot and select "Define Gating". Drag the boundary lines to cover the discontinuity, or right-click a line and choose "Set Value" to enter its position exactly. Finally, right-click and select "Transform back to frequency". For simple transmission-line discontinuities, this is much quicker and less error-prone than measuring the discontinuity separately and de-embedding it. How finely you can locate and remove a discontinuity depends on the maximum frequency of your data: the higher the frequency, the finer the resolution.

21. What is the “S-matrix combiner”?
This is wizard to combine separate S-parameter files into a larger S-matrix.
For instance, is you have a 2-ports network analyser and need to measure a 5-ports RF device, the wizard will guide you through the measurement of the minimum number required of 2-ports (.s2p) files (10 in this example) and then combine them into a single  .s5p file.

22. What other tools does Atyune include?
Atyune can display up to four plot formats at once, with markers, zoom and. Plots export as professional-quality SVG vector graphics for reports. Other tools include trace operations (such as merging traces, calculate averages, Q and potential bandwidth, stability factor…), a converter between RF quantities, and sub-matrix extraction. Atyune can also simulate electrically tuneable antennas using 2-port data from 3D electromagnetic simulators.

23. Can I change the default colours of the traces?
Yes. By default, the active trace is red and comparison traces are given random colours suited to the background. There are three ways to change this.

To change the colour of a single trace, right-click its item in the Inspect tab and choose a new colour.

To set a fixed colour order for all traces, use the Custom Colours Sequence option in the Preferences tab. It applies to both loaded and compared data. You define separate sequences for the dark and pale backgrounds. Sequences can be exported to and imported from a file.

To give each port of an S-matrix its own names and colours, right-click the data in the Inspect tab and select "User's Names and Colours". Colours can be picked one by one, generated at random, or blended as a gradient across the matrix. Port names, if given, are used to label the traces when you export plots. You can apply the scheme straight away, save it to a file, or set it as the default for all S-matrices with the same number of ports (turn on "User Names and Colours" in Preferences for this). These schemes are not applied to data opened in Compare mode, to avoid several traces sharing the same name and colour.

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