stubRadialShunt

Create single- and double-radial stub shunt on X-Y plane

Since R2021b

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Description

Use the stubRadialShunt object to create a single- or double-radial stub shunt on the X-Y plane.

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

Radial stubs provide broadly resonant RF short circuits by introducing the short at a concentrated point. When cascaded with high-impedance quarter-wavelength transmission lines, radial stubs provide an effectively decoupled network for microwave amplifiers and other active components.

Creation

Syntax

stub = stubRadialShunt
stub = stubRadialShunt(Name=Value)

Description

stub = stubRadialShunt creates a single-radial stub shunt in the X-Y plane. The stub dimensions are for the frequency range of 3-5 GHz with a resonant frequency of 4.2 GHz on the X-Y plane.

example

stub = stubRadialShunt(Name=Value) sets Properties using one or more name-value arguments. For example, stubRadialStub(OuterRadius=0.0070) creates a radial stub shunt with an outer radius of 0.0070 meters. Properties not specified retain their default values.

example

Properties

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Type of radial stub, specified as "Single" or "Double".

Example: stub = stubRadialShunt(StubType="Double")

Data Types: string | char

Outer radius of the radial stub in meters, specified as a positive scalar or a two-element vector of positive elements. Specify a two-element vector for a double-radial stub.

Example: stub = stubRadialShunt(OuterRadius=0.0070)

Data Types: double

Inner radius of the radial stub in meters, specified as a positive scalar or a two-element vector of positive elements. Specify a two-element vector for a double-radial stub.

Example: stub = stubRadialShunt(InnerRadius=0.0023)

Data Types: double

Angle of the stub in degrees, specified as a positive scalar or a two-element vector of positive elements. Specify a two-element vector for a double-radial stub. The stub angles must be greater than or equal to 5 degrees and less than or equal to 175 degrees.

Example: stub = stubRadialShunt(Angle=60)

Data Types: double

Width of the microstrip line in meters, specified as a positive scalar.

Example: stub = stubRadialShunt(PortLineWidth=0.0035)

Data Types: double

Length of the microstrip line in meters, specified as a positive scalar.

Example: stub = stubRadialShunt(PortLineLength=0.0237)

Data Types: double

Height of the radial stub from the ground plane, specified as a positive scalar.

Example: stub = stubRadialShunt(Height=0.0015)

Data Types: double

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

Example: stub = stubRadialShunt(GroundPlaneLength=0.046)

Example: double

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

Example: stub = stubRadialShunt(GroundPlaneWidth=0.046)

Example: double

Type of dielectric material used as a substrate, specified as a dielectric object. The dielectric material in a stubRadialShunt object with default properties is Teflon. The thickness of the default dielectric material Teflon is 0.8 mm or the same as the Height property.

Example: d = dielectric("FR4"); stub = stubRadialShunt(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 stubRadialShunt object with default properties is PEC.

Example: m = metal("PEC"); stub = stubRadialShunt(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: boolian

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
currentCalculate and plot current distribution
feedCurrentCalculate current at feed port
getZ0Calculate characteristic impedance of transmission line
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
optimizeOptimize pcb catalog object
EHfieldsElectric and magnetic fields of PCB components

Examples

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Open Live Script

Create a default radial stub shunt.

stub = stubRadialShunt
stub = 
  stubRadialShunt with properties:

             StubType: 'Single'
          OuterRadius: 0.0085
          InnerRadius: 0.0012
                Angle: 90
       PortLineLength: 0.0137
        PortLineWidth: 0.0025
               Height: 8.0000e-04
    GroundPlaneLength: 0.0200
     GroundPlaneWidth: 0.0200
            Substrate: [1×1 dielectric]
            Conductor: [1×1 metal]
           IsShielded: 0

View the radial stub shunt.

show(stub)

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

Open Live Script

Create shunt radial stub of type double.

stub = stubRadialShunt(StubType='double');
stub.OuterRadius = [0.0085 0.0065];
stub.InnerRadius = [0.0012 0.0008];
stub.Angle       = [90 60];

View shunt radial stub.

show(stub)

Plot s-parameters.

spar = sparameters(stub,linspace(3e9,5e9,50));
rfplot(spar)

More About

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References

[1] Wang , Zhebin, and Chan-Wang Park. “Novel Wideband GaN HEMT Power Amplifier Using Microstrip Radial Stub to Suppress Harmonics.” In 2012 IEEE/MTT-S International Microwave Symposium Digest, 1–3. Montreal, QC, Canada: IEEE, 2012. https://doi.org/10.1109/MWSYM.2012.6259464.

[2] Singh, Prashant, and Tiwary Anjini. “Novel Compact Dual Bandstop Filter Using Radial Stub.” Microwave Review 21 (September 1, 2015): 17–22.

Version History

Introduced in R2021b

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See Also