dipoleCycloid

Create cycloid dipole antenna

Description

The dipoleCycloid object is a half-wavelength cycloid dipole antenna. For the default cycloid dipole, the feed point is on the loop section. The default length is for an operating frequency of 48 MHz.

The width of the dipole is related to the circular cross-section by the equation

w=2d=4r

, where:

  • d is the diameter of equivalent cylindrical pole

  • r is the radius of equivalent cylindrical pole

For a given cylinder radius, use the cylinder2strip utility function to calculate the equivalent width.

Creation

Description

example

dc = dipoleCycloid creates a half-wavelength cycloid dipole antenna oriented along Z-axis.

example

dc = dipoleCycloid(Name,Value) creates a half-wavelength cycloid dipole antenna, with additional properties specified by one or more name-value pair 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 not specified retain their default values.

Properties

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Dipole length along z-axis, specified as a scalar in meters. By default, the length is for an operating frequency of 48 MHz.

Example: 'Length',0.9

Data Types: double

Dipole width, specified as a scalar in meters.

Example: 'Width',0.09

Data Types: double

Circular loop radius in X-Y plane, specified as a scalar in meters.

Example: 'LoopRadius',0.500

Data Types: double

Gap of loop in X-Y plane, specified as a scalar in meters.

Example: 'Gap',0.006

Data Types: double

Lumped elements added to the antenna feed, specified as the comma-separated pair consisting of 'Load' and a lumped element object handle. For more information, see lumpedElement.

Example: 'Load',lumpedelement. lumpedelement is the object handle for the load created using lumpedElement.

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

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

Data Types: double

Tilt axis of the antenna, specified as:

  • Three-element vectors of Cartesian coordinates in meters. In this case, each 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'

Object Functions

showDisplay antenna or array structure; Display shape as filled patch
infoDisplay information about antenna or array
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
designDesign prototype antenna or arrays for resonance at specified frequency
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
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
returnLossReturn loss of antenna; scan return loss of array
sparametersS-parameter object
vswrVoltage standing wave ratio of antenna

Examples

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Create a default cycloid dipole antenna using the dipoleCycloid object and view it.

dc = dipoleCycloid
dc = 
  dipoleCycloid with properties:

        Length: 1.2200
         Width: 0.0508
    LoopRadius: 0.3100
           Gap: 0.0400
          Tilt: 0
      TiltAxis: [1 0 0]
          Load: [1x1 lumpedElement]

show(dc)

Calculate the impedance of a cycloid dipole of width, 0.05 m, over a frequency span of 50 MHz - 100 MHz.

d = dipoleCycloid('Width',0.05);
impedance(d,linspace(50e6,100e6,51))

Plot the radiation pattern of a cycloid dipole of width,0.05 m, at a frequency of 48 MHz.

d = dipoleCycloid('Width',0.05)
d = 
  dipoleCycloid with properties:

        Length: 1.2200
         Width: 0.0500
    LoopRadius: 0.3100
           Gap: 0.0400
          Tilt: 0
      TiltAxis: [1 0 0]
          Load: [1x1 lumpedElement]

pattern(d,48e6)

References

[1] Balanis, C.A. Antenna Theory: Analysis and Design. 3rd Ed. New York: Wiley, 2005.

[2] Volakis, John. Antenna Engineering Handbook. 4th Ed. New York: McGraw-Hill, 2007.

Introduced in R2017a