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dipoleCylindrical

Create cylindrical dipole antenna

    Description

    The dipoleCylindrical object creates a cylindrical dipole antenna. The length of the cylindrical dipole corresponds to half of the wavelength at the operating frequency. These antennas are used in designing thicker dipole antennas. These antennas are mostly used in wireless communications due to their simple design.

    Cylindrical dipole antenna geometry, default radiation pattern, and impedance plot.

    Creation

    Description

    example

    ant = dipoleCylindrical creates a cylindrical dipole antenna object with default dimensions for an operating frequency of 70 MHz. The default dipole is center fed, with the feedpoint at the origin located on the y-z plane.

    example

    ant = dipoleCylindrical(Name,Value) sets Properties using one or more name-value pairs. For example, ant = dipoleCylindrical('Radius',0.04) creates a cylindrical dipole antenna with radius of 0.04 meters.

    Properties

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

    Example: 'Length',3

    Data Types: double

    Radius of the dipole, specified as a positive scalar in meters.

    Example: 'Radius',0.05

    Data Types: double

    Signed distance from the center along Z-axis, specified as a real-valued scalar in meters.

    Example: 'FeedOffset',-0.2

    Data Types: double

    Determine if the dipole ends are closed with a flat cap or left open, specified as 0 or 1. Specify 1 for closed ends of the dipole and 0 for open ends.

    Example: 'ClosedEnd',1

    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: m = metal('Copper'); 'Conductor',m

    Example: m = metal('Copper'); ant.Conductor = m

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

    Example: 'Tilt',90

    Example: ant.Tilt = 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:

    • 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, each specified as three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points in space.

    • A string input describing simple rotations around one of the principal axes, 'X', 'Y', or 'Z'.

    For more information, see Rotate Antennas and Arrays.

    Example: 'TiltAxis',[0 1 0]

    Example: 'TiltAxis',[0 0 0;0 1 0]

    Example: ant.TiltAxis = 'Z'

    Data Types: double

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

    Example: 'Load',lumpedelement, where lumpedelement is the load added to the antenna feed.

    Example: ant.Load = lumpedElement('Impedance',75)

    Object Functions

    showDisplay antenna or array structure; display shape as filled patch
    axialRatioAxial ratio of antenna
    beamwidthBeamwidth of antenna
    chargeCharge distribution on metal or dielectric antenna or array surface
    currentCurrent distribution on metal or dielectric antenna or array surface
    cylinder2stripCylinder equivalent width approximation
    designDesign prototype antenna or arrays for resonance around specified frequency
    efficiencyRadiation efficiency of antenna
    EHfieldsElectric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
    impedanceInput impedance of antenna; scan impedance of array
    meshMesh properties of metal or dielectric antenna or array structure
    meshconfigChange mesh mode of antenna structure
    optimizeOptimize antenna or array using SADEA optimizer
    patternRadiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
    patternAzimuthAzimuth pattern of antenna or array
    patternElevationElevation pattern of antenna or array
    rcsCalculate and plot radar cross section (RCS) of platform, antenna, or array
    returnLossReturn loss of antenna; scan return loss of array
    sparametersCalculate S-parameter for antenna and antenna array objects
    strip2cylinderCalculates equivalent radius approximation for strip
    vswrVoltage standing wave ratio of antenna

    Examples

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    Create a cylindrical dipole antenna with default properties.

    ant = dipoleCylindrical
    ant = 
      dipoleCylindrical with properties:
    
            Length: 2
            Radius: 0.0250
        FeedOffset: 0
         ClosedEnd: 0
         Conductor: [1x1 metal]
              Tilt: 0
          TiltAxis: [1 0 0]
              Load: [1x1 lumpedElement]
    
    

    View the antenna using the show function.

    show(ant)

    Figure contains an axes object. The axes object with title dipoleCylindrical antenna element contains 3 objects of type patch, surface. These objects represent PEC, feed.

    Plot the radiation pattern of the cylindrical dipole antenna at a frequency of 70 MHz.

    pattern(ant,70e6)

    Figure contains an axes object and other objects of type uicontrol. The axes object contains 3 objects of type patch, surface.

    Create a center-fed cylindrical dipole with a length of 2 m and a radius of 0.06 m.

    ant = dipoleCylindrical('Length',2,'Radius',0.06)
    ant = 
      dipoleCylindrical with properties:
    
            Length: 2
            Radius: 0.0600
        FeedOffset: 0
         ClosedEnd: 0
         Conductor: [1x1 metal]
              Tilt: 0
          TiltAxis: [1 0 0]
              Load: [1x1 lumpedElement]
    
    

    Plot the impedance over a frequency range of 50 MHz to 120 MHz.

    impedance(ant,linspace(50e6,120e6,51))

    Figure contains an axes object. The axes object with title Impedance contains 2 objects of type line. These objects represent Resistance, Reactance.

    Create a cylindrical dipole antenna with a open-ended top and closed-ended top respectively.

    ant = dipoleCylindrical("Radius",0.1);
    ant_ClosedEnded = dipoleCylindrical("Radius",0.1,"ClosedEnd",1);

    Calculate and plot the current distribution for a cylindrical dipole antennas at 70MHz frequency.

    I_OpenEnded = current(ant,70e6)
    I_OpenEnded = 3×400 complex
    
      -0.0000 - 0.0002i  -0.0000 - 0.0005i  -0.0000 - 0.0007i  -0.0000 - 0.0005i  -0.0000 - 0.0002i   0.0000 + 0.0002i   0.0000 + 0.0005i   0.0000 + 0.0007i   0.0000 + 0.0005i   0.0000 + 0.0002i   0.0000 + 0.0003i   0.0000 + 0.0007i   0.0000 + 0.0009i   0.0000 + 0.0007i   0.0000 + 0.0003i  -0.0000 - 0.0003i  -0.0000 - 0.0007i  -0.0000 - 0.0009i  -0.0000 - 0.0007i  -0.0000 - 0.0003i  -0.0000 - 0.0001i  -0.0000 - 0.0002i  -0.0000 - 0.0002i  -0.0000 - 0.0002i  -0.0000 - 0.0001i   0.0000 + 0.0001i   0.0000 + 0.0002i   0.0000 + 0.0002i   0.0000 + 0.0002i   0.0000 + 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0001i   0.0000 + 0.0000i  -0.0000 - 0.0000i  -0.0000 - 0.0001i  -0.0001 - 0.0001i  -0.0000 - 0.0001i  -0.0000 - 0.0000i  -0.0000 - 0.0000i  -0.0001 - 0.0001i  -0.0001 - 0.0001i  -0.0001 - 0.0001i  -0.0000 - 0.0000i   0.0000 + 0.0000i   0.0001 + 0.0001i   0.0001 + 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0000i
       0.0000 + 0.0006i   0.0000 + 0.0004i   0.0000 + 0.0000i  -0.0000 - 0.0004i  -0.0000 - 0.0006i  -0.0000 - 0.0006i  -0.0000 - 0.0004i   0.0000 + 0.0000i   0.0000 + 0.0004i   0.0000 + 0.0006i  -0.0000 - 0.0008i  -0.0000 - 0.0005i   0.0000 + 0.0000i   0.0000 + 0.0005i   0.0000 + 0.0008i   0.0000 + 0.0008i   0.0000 + 0.0005i   0.0000 + 0.0000i  -0.0000 - 0.0005i  -0.0000 - 0.0008i   0.0000 + 0.0002i   0.0000 + 0.0001i   0.0000 + 0.0000i  -0.0000 - 0.0001i  -0.0000 - 0.0002i  -0.0000 - 0.0002i  -0.0000 - 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0001i   0.0000 + 0.0002i  -0.0001 - 0.0001i  -0.0000 - 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0001i   0.0001 + 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0001i   0.0000 + 0.0000i  -0.0000 - 0.0001i  -0.0001 - 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0000i  -0.0000 - 0.0000i  -0.0001 - 0.0001i  -0.0001 - 0.0001i  -0.0000 - 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0001 + 0.0001i
      -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0191 - 0.0016i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0190 + 0.0033i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0189 + 0.0036i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0185 + 0.0046i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i  -0.0183 + 0.0049i
    
    
    current(ant,70e6)

    Figure contains an axes object. The axes object with title Current distribution contains 3 objects of type patch.

    I_ClosedEnded = current(ant_ClosedEnded,70e6)
    I_ClosedEnded = 3×428 complex
    
      -0.0000 - 0.0002i  -0.0000 - 0.0005i  -0.0000 - 0.0007i  -0.0000 - 0.0005i  -0.0000 - 0.0002i   0.0000 + 0.0002i   0.0000 + 0.0005i   0.0000 + 0.0007i   0.0000 + 0.0005i   0.0000 + 0.0002i   0.0000 + 0.0003i   0.0000 + 0.0007i   0.0000 + 0.0008i   0.0000 + 0.0007i   0.0000 + 0.0003i  -0.0000 - 0.0003i  -0.0000 - 0.0007i  -0.0000 - 0.0008i  -0.0000 - 0.0007i  -0.0000 - 0.0003i  -0.0000 - 0.0001i  -0.0000 - 0.0002i  -0.0000 - 0.0002i  -0.0000 - 0.0002i  -0.0000 - 0.0001i   0.0000 + 0.0001i   0.0000 + 0.0002i   0.0000 + 0.0002i   0.0000 + 0.0002i   0.0000 + 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0001i   0.0000 + 0.0000i  -0.0000 - 0.0000i  -0.0000 - 0.0001i  -0.0001 - 0.0001i  -0.0000 - 0.0001i  -0.0000 - 0.0000i  -0.0000 - 0.0000i  -0.0001 - 0.0001i  -0.0001 - 0.0001i  -0.0001 - 0.0001i  -0.0000 - 0.0000i   0.0000 + 0.0000i   0.0001 + 0.0001i   0.0001 + 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0000i
       0.0000 + 0.0006i   0.0000 + 0.0004i   0.0000 + 0.0000i  -0.0000 - 0.0004i  -0.0000 - 0.0006i  -0.0000 - 0.0006i  -0.0000 - 0.0004i   0.0000 + 0.0000i   0.0000 + 0.0004i   0.0000 + 0.0006i  -0.0000 - 0.0008i  -0.0000 - 0.0005i   0.0000 + 0.0000i   0.0000 + 0.0005i   0.0000 + 0.0008i   0.0000 + 0.0008i   0.0000 + 0.0005i   0.0000 + 0.0000i  -0.0000 - 0.0005i  -0.0000 - 0.0008i   0.0000 + 0.0002i   0.0000 + 0.0001i   0.0000 + 0.0000i  -0.0000 - 0.0001i  -0.0000 - 0.0002i  -0.0000 - 0.0002i  -0.0000 - 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0001i   0.0000 + 0.0002i  -0.0001 - 0.0001i  -0.0000 - 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0001i   0.0001 + 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0001i   0.0000 + 0.0000i  -0.0000 - 0.0001i  -0.0001 - 0.0001i   0.0001 + 0.0001i   0.0000 + 0.0000i   0.0000 + 0.0000i  -0.0000 - 0.0000i  -0.0001 - 0.0001i  -0.0001 - 0.0001i  -0.0000 - 0.0000i   0.0000 + 0.0000i   0.0000 + 0.0000i   0.0001 + 0.0001i
      -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0180 - 0.0011i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0179 + 0.0038i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0178 + 0.0041i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0175 + 0.0052i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i  -0.0173 + 0.0055i
    
    
    figure;
    current(ant_ClosedEnded,70e6)

    Figure contains an axes object. The axes object with title Current distribution contains 3 objects of type patch.

    More About

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    References

    [1] King Ronald W.P. Characteristics of Cylindrical Dipoles and Monopoles. Boston, MA: Springer, 1971.

    Introduced in R2021a