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Create J-dipole antenna


Use the dipoleJ object to create a J-dipole on the yz-plane. The antenna contains a half-wavelength radiator and a quarter-wavelength stub. The default antenna dimensions are set for an operating frequency of 144MHz.




jdipole = dipoleJ creates a J-dipole antenna at an operating frequency of 144MHz.


jdipole = dipoleJ(Name=Value) creates a J-dipole antenna with additional Properties specified by one or more name-value arguments. Name is the property name and Value is the corresponding value. You can specify several name-value pair arguments in any order as Name1=Value1, ..., NameN=ValueN. Properties that you do not specify retain their default values.


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Radiator length, specified as a positive scalar in meters.

Example: 0.9

Data Types: double

Parallel line stub length, specified as a positive scalar in meters.

Example: 0.3

Data Types: double

Strip width, specified as a positive scalar in meters.

Example: 0.0500

Data Types: double

Space between the parallel line stub and the radiator, specified as a scalar in meters.

Example: 0.0500

Data Types: double

Signed distance to the feed from the base of stub on the large arm, specified as a scalar in meters.

Example: 0.0345

Data Types: double

Type of the metal used as a conductor, specified as a metal material object. You can choose any metal from the MetalCatalog or specify a metal of your choice. For more information, see metal. For more information on metal conductor meshing, see Meshing.

Example: metal("Copper")

Lumped elements added to the antenna feed, specified as a lumped element object. You can add a load anywhere on the surface of the antenna. By default, the load is at the origin. For more information, see lumpedElement.

Example: lumpedElement(Impedance=75)

Tilt angle of the antenna in degrees, specified as a scalar or vector. For more information, see Rotate Antennas and Arrays.

Example: 90

Example: Tilt=[90 90],TiltAxis=[0 1 0;0 1 1] tilts the antenna at 90 degrees about the two axes defined by the vectors.

Data Types: double

Tilt axis of the antenna, specified as one of these values:

  • Three-element vector of Cartesian coordinates in meters. In this case, each coordinate in the vector starts at the origin and lies along the specified points on the x-, y-, and z-axes.

  • Two points in space, specified as a 2-by-3 matrix corresponding to two three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points.

  • "x", "y", or "z" to describe a rotation about the x-, y-, or z-axis, respectively.

For more information, see Rotate Antennas and Arrays.

Example: [0 1 0]

Example: [0 0 0;0 1 0]

Example: "Z"

Data Types: double | string

Object Functions

axialRatioCalculate and/or plot axial ratio of antenna or array
bandwidthCalculate and/or plot absolute bandwidth of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on antenna or array surface
currentCurrent distribution on antenna or array surface
designDesign prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
efficiencyRadiation efficiency of antenna
EHfieldsElectric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
impedanceInput impedance of antenna or scan impedance of array
infoDisplay information about antenna, array, or platform
memoryEstimateEstimate memory required to solve antenna or array mesh
meshMesh properties of metal, dielectric antenna, or array structure
meshconfigChange meshing mode of antenna, array, custom antenna, custom array, or custom geometry
optimizeOptimize antenna or array using SADEA optimizer
patternPlot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array
patternAzimuthAzimuth plane radiation pattern of antenna or array
patternElevationElevation plane radiation pattern of antenna or array
rcsCalculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequencyCalculate and/or plot resonant frequency of antenna
returnLossReturn loss of antenna or scan return loss of array
showDisplay antenna, array structures, shapes, or platform
sparametersCalculate S-parameters for antennas and antenna arrays
vswrVoltage standing wave ratio (VSWR) of antenna or array element
wireStackCreate single or multi-feed wire antenna


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Create and view a default J-dipole antenna.

d = dipoleJ
d = 
  dipoleJ with properties:

    RadiatorLength: 0.9970
        StubLength: 0.4997
           Spacing: 0.0460
             Width: 0.0200
        FeedOffset: -0.6994
         Conductor: [1x1 metal]
              Tilt: 0
          TiltAxis: [1 0 0]
              Load: [1x1 lumpedElement]


Create and view a J-dipole antenna with the following specifications:

  1. Radiator length = 0.978 m

  2. Stub length = 0.485 m

  3. FeedOffset = 0.049 m

dj = dipoleJ(RadiatorLength=0.978, StubLength=0.485, ...

Calculate the impedance of the antenna over a frequency span 140MHz - 150MHz.


Version History

Introduced in R2018a