Engee documentation

rfckt.coaxial

Creates a coaxial transmission line.

Library

EngeeRF

Description

Use the function rfckt.coaxial to create a coaxial transmission line characterized by the size of the line, the type of loop and the closure.

The following figure shows the cross-section of a coaxial transmission line. Its physical characteristics include the radius of the inner conductor of the coaxial transmission line and the radius of the outer conductor .

rfckt coaxial en

Syntax

Function call

  • h = rfckt.coaxial() — creates a coaxial transmission line object with default properties.

  • h = rfckt.coaxial(Name=Value) — sets properties specified by one or more name-value arguments. Unspecified properties retain their default values.

Arguments

Name-value input arguments

Specify optional argument pairs as Name=Value, where Name — the name of the argument, and Value — the appropriate value.

Example: rfckt.coaxial(OuterRadius = 0.0043) creates a coaxial transmission line object with an external radius 0.0043 meters. You can specify multiple name-value pairs.

# AnalyzedResult — calculated values of S-parameters, noise factor, OIP3 and group delay

+ the rfdata.data object

Details

Calculated values of S-parameters, noise factor, OIP3, and group delay, set as an object rfdata.data. For more information, see Algorithms.

This argument is read-only.
Типы данных

function_handle

# lineLength — the physical length of the transmission line, m

+ 0.01 (by default) | scalar

Details

The physical length of the transmission line, specified as a scalar in meters.

Типы данных

Float64

# outerRadius is the radius of the outer conductor, m

+ 0.0026 (by default) | scalar

Details

The radius of the outer conductor, set as a scalar in meters.

Типы данных

Float64

# innerRadius is the radius of the inner conductor, m

+ 7.25e−4 (by default) | scalar

Details

The radius of the inner conductor, set as a scalar in meters.

Типы данных

Float64

# EpsilonR — relative permittivity

+ 2.3 (by default) | scalar

Details

The relative permittivity of a dielectric, given as a scalar. The relative permittivity is the ratio of the dielectric constant of a dielectric to dielectric constant in vacuum .

Типы данных

Float64

# MuR — relative magnetic permeability of a dielectric

+ 1 (by default) | scalar

Details

The relative magnetic permeability of a dielectric, given as a scalar. The relative magnetic permeability is the ratio of the magnetic permeability of a dielectric magnetic permeability in vacuum .

Типы данных

Float64

# LossTangent is the tangent of the dielectric loss angle

+ 0 (by default) | scalar

Details

The tangent of the dielectric loss angle, defined as a scalar.

Типы данных

Float64

# SigmaCond — linear conductivity, Cm/m

+ Inf (by default) | scalar

Details

Linear conductivity, given as a scalar in Siemens per meter (Cm/m).

Типы данных

Float64

# StubMode — loop type

+ "NotAStub" (by default) | "Series" | "Shunt"

Details

The type of loop specified by one of the following values: "NotAStub", "Series", "Shunt".

# Termination — closing of the transmission loop
"NotApplicable" (by default) | "Open" | "Short"

Details

The short circuit of the transmission loop, set by one of the following values: "NotApplicable", "Open", "Short".

# Name — the name of the object

+ "Coaxial Transmission Line" (default) | line

Details

The name of the object, set as a string.

This argument is read-only.
Типы данных

String

# NPort — number of ports

+ 2 (default) | a positive integer

Details

The number of ports specified as a positive integer.

This argument is read-only.
Типы данных

Int64

Output arguments

# h — the object of the coaxial transmission line

+ object

Details

The object of the coaxial transmission line.

Examples

Creating a coaxial transmission line

Details

Create a coaxial transmission line with an external radius 0.0045 m, using the function rfckt.coaxial.

using EngeeRF

h = rfckt.coaxial(OuterRadius = 0.0045)

println("OuterRadius: ", h.OuterRadius,
        "\nInnerRadius: ", h.InnerRadius,
        "\nMuR: ", h.MuR,
        "\nEpsilonR: ", h.EpsilonR,
        "\nLossTangent: ", h.LossTangent,
        "\nSigmaCond: ", h.SigmaCond,
        "\nLineLength: ", h.LineLength,
        "\nStubMode: ", h.StubMode,
        "\nTermination: ", h.Termination,
        "\nnPort: ", h.nPort,
        "\nAnalyzedResult: ", h.AnalyzedResult,
        "\nName: ", h.Name)
OuterRadius: 0.0045
InnerRadius: 0.000725
MuR: 1.0
EpsilonR: 2.3
LossTangent: 0.0
SigmaCond: Inf
LineLength: 0.01
StubMode: NotAStub
Termination: NotApplicable
nPort: 2
AnalyzedResult: nothing
Name: Coaxial Transmission Line

Algorithms

Method analyze considers the transmission line as a two-port linear network. It calculates the property AnalyzedResult for a loop line or a line without a loop, using the data stored in the object properties rfckt.coaxial, as follows:

  • If we model the transmission line as a line without a loop, the method analyze First, it calculates the ABCD parameters at each frequency contained in the vector of simulated frequencies. Then he uses the function abcd2s to convert ABCD parameters to S parameters.

    Method analyze calculates the ABCD parameters using the physical length of the transmission line and a comprehensive distribution constant , using the following equations:







    where and — vectors, the elements of which correspond to the elements of the frequency vector specified in the input argument Freq functions analyze. Both vectors can be expressed in terms of resistance , inductance , conductivity and capacity per unit length (meters) as follows:



    where







    In the equations given above:

    • — radius of the inner conductor;

    • — radius of the external conductor;

    • — linear conductivity;

    • — magnetic permeability of the dielectric;

    • — dielectric constant of the dielectric;

    • — the imaginary part , where

      • — dielectric constant in vacuum;

      • — the value of the argument EpsilonR;

      • — the value of the argument LossTangent;

    • — the depth of current penetration into the conductor;

    • — the vector of simulated frequencies determined by the block Outport (CE).

  • If we model the transmission line as a parallel or serial loop, the method analyze first, it calculates the ABCD parameters at the specified frequencies. Then he uses the function abcd2s to convert ABCD parameters to S parameters.

    If for an argument StubMode the value is set "Shunt", then the two-port network consists of a loopback transmission line that can be closed or opened, as shown in the following figure.

    rfckt coaxial 1

    Here — input impedance of the parallel circuit. The ABCD parameters for the parallel loop are calculated as follows:







    If for an argument StubMode the value is set "Series", then the two-port network is a serial transmission line that can be closed or opened, as shown in the following figure.

    rfckt coaxial 2

    Here — input impedance of the serial circuit. The ABCD parameters for the serial loop are calculated as follows:







Literature

  1. Pozar, David M. Microwave Engineering, John Wiley & Sons, Inc., 2005.