README.md

Microwave Networks

A C# library implementing common tools for working with microwave networks including reading/writing to Touchstone (.snp) files, de/embedding network parameters, etc. Download:

• NuGet
• GitHub Packages

Currently Supported Features

• Full support for Touchstone file format version 1.0
• Cascading/embedding/de-embedding 2-port networks
• S and T parameters

Future/In Development Features

• Full support for Touchstone file format version 2.0
• Cascading n-port networks using the symmetry extension method
• Other parameter types (admittance, impedance, etc.)
• Interpolation

Examples

Network Data

Create a Two-Port S-Parameters Matrix

// Simple "ideal" 3 dB attenuator at some frequency with an excellent match
ScatteringParametersMatrix atten = new ScatteringParametersMatrix(numPorts: 2)
{
    [1, 1] = NetworkParameter.FromPolarDecibelDegree(-50, 0),
    [1, 2] = NetworkParameter.FromPolarDecibelDegree(-3, 0),
    [2, 1] = NetworkParameter.FromPolarDecibelDegree(-3, 0),
    [2, 2] = NetworkParameter.FromPolarDecibelDegree(-50, 0)
};

Create Frequency-Dependent Network Data

NetworkParameter ten_dBLoss = NetworkParameter.FromPolarDecibelDegree(-10, 0);
var exampleData = new NetworkParametersCollection<ScatteringParametersMatrix>(2)
{
    // Create a new 2-port S-parameter matrix, and set S21 to a scalard 10 dB loss.
    [1.0e9] = new ScatteringParametersMatrix(2) { [2, 1] = ten_dBLoss },
    // Alternatively, can index the frequency and specific matrix index all at once
    // i.e. at 2 GHz, set S21 to -10 dB
    [2.0e9, 2, 1] = ten_dBLoss,
    // etc.
    [5.0e9, 2, 1] = ten_dBLoss
};

Touchstone Files

Simple File IO

Reading All Touchstone Data From a File

INetworkParametersCollection coll = Touchstone.ReadAllData(@"C:\example.s2p");
foreach (FrequencyParametersPair pair in coll)
{
    (double frequency, NetworkParametersMatrix matrix) = pair;
    double insertionLoss = matrix[2, 1].Magnitude_dB;
    Console.WriteLine($"Insertion loss at {frequency} is {insertionLoss} dB");
}

Writing All Touchstone Data to a File

This example uses the exampleData collection shown in Create Frequency-Dependent Network Data.

// Create a new Touchstone file with all default settings
Touchstone tsFile = new Touchstone(exampleData);
tsFile.Write(@"C:\example_data.s2p");

Advanced File IO

Enumerating/Filtering Touchstone Data with LINQ

Rather than loading all of the data into memory, the following example enumerates each matrix one at a time from a file to allow for runtime manipulation without allocating unnecessary memory.

string path = @"C:\example.s2p";
var filteredInsertionLoss = from FrequencyParametersPair pair in Touchstone.ReadData(path)
                            where pair.Frequency_Hz > 2.0e9 && pair.Frequency_Hz < 5.0e9
                            let InsertionLoss_dB = pair.Parameters[2, 1].Magnitude_dB
                            select new { pair.Frequency_Hz, InsertionLoss_dB };

Streaming Touchstone Data to a File

The TouchstoneWriter and TouchstoneReader classes allow for precise control over Touchstone File IO, including full support for asynchronous file operations. This example uses the exampleData collection shown in Create Frequency-Dependent Network Data.

TouchstoneWriterSettings settings = new TouchstoneWriterSettings
{
    IncludeColumnNames = true,
    NumericFormatString = "G3"
};

using (TouchstoneWriter writer = TouchstoneWriter.Create(@"C:\example_data.s2p", settings))
{
    writer.Options.FrequencyUnit = FrequencyUnit.GHz;

    writer.WriteCommentLine("This is an example comment at the top of the file.");
    // The header will be written automatically if not called manually as soon as the first call is made to WriteData(). 
    // However, you can manually invoke this if you would like to control where it is placed in relation to other comments.
    writer.WriteHeader();

    foreach (FrequencyParametersPair pair in exampleData)
        writer.WriteData(pair);
}