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txlineCoaxial

Create coaxial transmission line

Description

Use the txlineCoaxial object to create a coaxial transmission line. A cross-section of a coaxial transmission line is shown in this figure. The physical characteristics of a coaxial transmission line include the radius of the inner conductor, a and the radius of the outer conductor, b.

Creation

Description

coaxialtxline = txlineCoaxial creates a default coaxial transmission line object.

example

coaxialtxline = txlineCoaxial(Name,Value) sets Properties using one or more name-value pairs. For example, txline = txlineCoaxial('OuterRadius',0.0046) creates a coaxial transmission line with an outer radius of 0.0046 meters.

Properties

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Name of the coaxial transmission line, specified as a string scalar or a character vector.

Example: 'Name','coaxial1'

Example: coaxialtxline.Name = 'coaxial1'

Data Types: char | string

Outer conductor radius, specified as a positive scalar in meters.

Example: 'OuterRadius',0.0074

Example: coaxialtxline.OuterRadius = 0.0074

Data Types: double

Inner conductor radius, specified as a positive scalar in meters.

Example: 'InnerRadius',0.000875

Example: coaxialtxline.InnerRadius = 0.000875

Data Types: double

Relative permeability of the dielectric, specified as a positive scalar.

Relative permeability is the ratio of the permeability of the dielectric, μ, to the permeability in free space, μ0.

Example: 'MuR',1.5

Example: coaxialtxline.MuR = 1.5

Data Types: double

Relative permittivity of the dielectric, specified as a positive scalar.

Example: 'EpsilonR',1.4

Example: coaxialtxline.EpsilonR = 1.4

Data Types: double

Loss angle tangent of the dielectric, specified as a nonnegative scalar.

Example: 'LossTangent',1

Example: coaxialtxline.LossTangent = 1

Data Types: double

Conductivity of the conductor, specified as a nonnegative scalar in Siemens per meter (S/m).

Example: 'SigmaCond',2

Example: coaxialtxline.SigmaCond = 2

Data Types: double

Physical length of the coaxial transmission line, specified as a positive scalar in meters.

Example: 'LineLength',0.2

Example: coaxialtxline.LineLength = 0.2

Data Types: double

Stub transmission line termination, specified as 'NotApplicable', 'Open', or 'Short'.

Example: 'Termination','Short'

Example: coaxialtxline.Termination = 'Short'

Data Types: char

Type of stub, specified as 'NotAStub', 'Series', or 'Shunt'.

Example: 'StubMode','Series'

Example: coaxialtxline.StubMode = 'Series'

Data Types: char

This property is read-only.

Number of input and output ports, specified as a positive scalar.

Data Types: double

This property is read-only.

Terminals of coaxial transmission line, specified as cell array of strings.

Data Types: char | string

Object Functions

sparametersS-parameter object
groupdelayGroup delay of S-parameter object or RF filter object or RF Toolbox circuit object
noisefigureCalculate noise figure of transmission lines
getZ0Calculate characteristic impedance of transmission line object
circuitCircuit object
cloneCreate copy of existing circuit element or circuit object

Examples

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Create a coaxial transmission line with these specifications:

  • Outside diameter of the conductor : 0.45 mm,

  • Inside diameter of the conductor : 1.47 mm

  • Conductor conductivity : 5.8e7

  • Relative permittivity of polyimide dielectric : 3.4

coaxialtxline = txlineCoaxial('OuterRadius',1.47e-3,'InnerRadius',0.45e-3,...
            'EpsilonR',3.4,'SigmaCond',5.8e7)
coaxialtxline = 
  txlineCoaxial: Coaxial element

           Name: 'Coaxial'
    OuterRadius: 0.0015
    InnerRadius: 4.5000e-04
            MuR: 1
       EpsilonR: 3.4000
    LossTangent: 0
      SigmaCond: 58000000
     LineLength: 0.0100
    Termination: 'NotApplicable'
       StubMode: 'NotAStub'
       NumPorts: 2
      Terminals: {'p1+'  'p2+'  'p1-'  'p2-'}

Calculate the characteristic impedance of the transmission line.

charimpedance = getZ0(coaxialtxline,6e9)
charimpedance = 38.4927 - 0.0201i
Introduced in R2020b