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# 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

expand all

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 xy- plane, specified as a scalar in meters.

Example: 'LoopRadius',0.500

Data Types: double

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

Example: 'Gap',0.006

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

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

Example: 'Load',lumpedelement. lumpedelement is the object 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 degrees about the two axes defined by the vectors.

Note

The wireStack antenna object only accepts the dot method to change its properties.

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: TiltAxis = 'Z'

Note

The wireStack antenna object only accepts the dot method to change its properties.

Data Types: double

## Object Functions

 show Display antenna, array structures or shapes info Display information about antenna or array axialRatio Axial ratio of antenna beamwidth Beamwidth of antenna charge Charge distribution on antenna or array surface current Current distribution on antenna or array surface design Design prototype antenna or arrays for resonance around specified frequency efficiency Radiation efficiency of antenna EHfields Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays impedance Input impedance of antenna; scan impedance of array mesh Mesh properties of metal, dielectric antenna, or array structure meshconfig Change mesh mode of antenna structure optimize Optimize antenna or array using SADEA optimizer pattern Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array patternAzimuth Azimuth pattern of antenna or array patternElevation Elevation pattern of antenna or array rcs Calculate and plot radar cross section (RCS) of platform, antenna, or array returnLoss Return loss of antenna; scan return loss of array sparameters Calculate S-parameter for antenna and antenna array objects vswr Voltage 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
Conductor: [1x1 metal]
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
Conductor: [1x1 metal]
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.

## Version History

Introduced in R2017a