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couplerBranchline

Create branch line coupler or quadrature hybrid

Since R2021b

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Description

Use the couplerBranchline object to create a branch line coupler or a quadrature hybrid. A branch line coupler or a quadrature hybrid divides the power between two ports with a phase difference of 90 degrees. This PCB component has four ports. By default, port 1 is the input port, port 2 is the through port, port 4 is the coupled port, and port 3 is the isolated port.

Three part image from right to left: Default image of a branchline coupler. Current distribution on the branchline coupler. S-parameters plot of the branchline coupler.

To analyze the behavioral model for the branchline coupler, set the Behavioral property in the sparameters to true or 1.

Creation

Syntax

coupler = couplerBranchline
coupler = couplerBranchline(Name=Value)

Description

coupler = couplerBranchline creates a branch line coupler with default property values for a frequency of 3 GHz.

example

coupler = couplerBranchline(Name=Value) sets Properties using one or more name-value arguments. For example, couplerBranchline(PortLineLength=0.0286) creates a branch line coupler of length 0.0286 meters. Properties not specified retain their default values.

Properties

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Length of the input and the output line in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(PortLineLength=0.0286)

Data Types: double

Width of the input and the output line in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(PortLineWidth=0.0070)

Data Types: double

Length of the series arm in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(SeriesArmLength=0.0286)

Data Types: double

Width of the series arm in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(SeriesArmWidth=0.0096)

Data Types: double

Length of the shunt arm in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(ShuntArmLength=0.0286)

Data Types: double

Width of the shunt arm in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(ShuntArmWidth=0.0096)

Data Types: double

Height of the branch line coupler from the ground plane in meters, specified as a positive scalar.

In the case of a multilayer substrate, you can use the Height property to create a branch line coupler line where the two dielectrics interface.

Example: coupler = couplerBranchline(Height=0.0076)

Data Types: double

Width of the ground plane in meters, specified as a positive scalar.

Example: coupler = couplerBranchline(GroundPlaneWidth=0.046)

Example: double

Type of dielectric material used as a substrate, specified as a dielectric object. The dielectric material in a couplerBranchline object with default properties is RTDuroid

Example: d = dielectric("FR4"); coupler = couplerBranchline(Substrate=d)

Data Types: string | char

Type of metal used in the conducting layers, specified as a metal object. The type of metal in a couplerBranchline object with default properties is Copper.

Example: m = metal("PEC"); coupler = couplerBranchline(Conductor=m)

Data Types: string | char

Flag to add a metal shielding to the PCB component, specified as a logical 0 or logical 1. The default value is logical 0.

Example: IsShielded = true or 1 add a metal shield.

Note

To enable FEM solver required for the metal shield property, download the Integro-Differential Modeling Framework for MATLAB. To download this add-on:

  1. In the Home tab Environment section, click on Add-Ons. This opens the add-on explorer. You need an active internet connection to download the add-on.

  2. Search for Integro-Differential Modeling Framework for MATLAB and click Install.

  3. To verify if the download is successful, run 

    matlab.addons.installedAddons
    in your MATLAB® session command line.

  4. On Windows, to run the IDMF add-on, you must install the Windows Subsystem for Linux (WSL). To install WSL, see Install Linux on Windows with WSL.

    The Windows Defender Firewall can block the PostgreSQL server when using the IDMF add-on. To resolve this issue, you can allow the server to communicate on desired networks if the firewall prompts. Alternatively, you can manually add the executable file of the PostgreSQL server located in <matlabroot>\sys\postgresql\win64\PostgreSQL\bin\postgres.exe. For more information, see https://support.microsoft.com/en-us/windows/risks-of-allowing-apps-through-windows-defender-firewall-654559af-3f54-3dcf-349f-71ccd90bcc5c.

Data Types: logical

This property is read-only.

Metal shield for the PCB component, specified as a shape.Box object. The length and width of the box must be equal to the length and width of the ground plane. The center of the box is at [0 0 Shielding.Height].

Dependencies

To enable the Shielding property, set the IsShielded property to true or 1.

Type of RF connector assembled at the feed locations of the PCB component, specified as a RFConnector object.

Example: Create connector from RFConnector object like this: coaxial = RFConnector adds a coaxial connector.

Dependencies

To enable the Connector property, set the IsShielded property to true or 1.

Object Functions

chargeCalculate and plot charge distribution
couplingCalculate coupling factor of coupler
currentCalculate and plot current distribution
designDesign branchline coupler around particular frequency
directivityCalculate directivity of coupler
feedCurrentCalculate current at feed port
getZ0Calculate characteristic impedance of transmission line
isolationCalculate isolation of coupler
layoutPlot all metal layers and board shape
meshChange and view mesh properties of metal or dielectric in PCB component
shapesExtract all metal layer shapes of PCB component
showDisplay PCB component structure or PCB shape
sparametersCalculate S-parameters for RF PCB objects
RFConnectorCreate RF connector

Examples

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Open Live Script

Create and view a default branchline coupler.

coupler = couplerBranchline
coupler = 
  couplerBranchline with properties:

      PortLineLength: 0.0186
       PortLineWidth: 0.0051
     SeriesArmLength: 0.0184
      SeriesArmWidth: 0.0083
      ShuntArmLength: 0.0186
       ShuntArmWidth: 0.0051
              Height: 0.0016
    GroundPlaneWidth: 0.0600
           Substrate: [1x1 dielectric]
           Conductor: [1x1 metal]
          IsShielded: 0


show(coupler)

Figure contains an axes object. The axes object with title couplerBranchline element, xlabel x (mm), ylabel y (mm) contains 8 objects of type patch, surface. These objects represent PEC, feed, Teflon.

References

[1] Pozar, David M. Microwave Engineering. 4th ed. Hoboken, NJ: Wiley, 2012.

Version History

Introduced in R2021b

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See Also

Topics