dipoleCylindrical

Create cylindrical dipole antenna

Since R2021a

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.

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.

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'.

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.

Object Functions

 axialRatio Calculate and/or plot axial ratio of antenna or array bandwidth Calculate and/or plot absolute bandwidth of antenna beamwidth Beamwidth of antenna charge Charge distribution on antenna or array surface current Current distribution on antenna or array surface cylinder2strip Cylinder equivalent width approximation design Design prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects efficiency Radiation efficiency of antenna EHfields Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays impedance Input impedance of antenna or scan impedance of array info Display information about antenna, array, or platform memoryEstimate Estimate memory required to solve antenna or array mesh mesh Mesh properties of metal, dielectric antenna, or array structure meshconfig Change meshing mode of antenna, array, custom antenna, custom array, or custom geometry optimize Optimize antenna or array using SADEA optimizer pattern Plot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array patternAzimuth Azimuth plane radiation pattern of antenna or array patternElevation Elevation plane radiation pattern of antenna or array rcs Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array resonantFrequency Calculate and/or plot resonant frequency of antenna returnLoss Return loss of antenna or scan return loss of array show Display antenna, array structures, shapes, or platform sparameters Calculate S-parameters for antennas and antenna arrays strip2cylinder Calculate equivalent radius approximation for strip vswr Voltage standing wave ratio (VSWR) of antenna or array element

Examples

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Create a cylindrical dipole antenna with default properties.

ant = dipoleCylindrical
ant =
dipoleCylindrical with properties:

Length: 2
FeedOffset: 0
ClosedEnd: 0
Conductor: [1x1 metal]
Tilt: 0
TiltAxis: [1 0 0]

View the antenna using the show function.

show(ant)

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

pattern(ant,70e6)

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

ant =
dipoleCylindrical with properties:

Length: 2
FeedOffset: 0
ClosedEnd: 0
Conductor: [1x1 metal]
Tilt: 0
TiltAxis: [1 0 0]

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

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

Create cylindrical dipole antennas with an open-ended top and a close-ended top, respectively.

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

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)

I_ClosedEnded = current(ant_ClosedEnded,70e6)
I_ClosedEnded = 3×424 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
-0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0181 - 0.0011i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 0.0038i  -0.0180 + 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)

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References

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

Version History

Introduced in R2021a