dipoleCylindrical

Create cylindrical dipole antenna

Since R2021a

Description

The dipoleCylindrical object creates a center-fed cylindrical dipole antenna resonating around 70 MHz. The length of the cylindrical dipole corresponds to half of the wavelength at the operating frequency. These antennas are used in wireless communication applications requiring thicker dipoles due to their simple design.

Creation

Syntax

ant = dipoleCylindrical

ant = dipoleCylindrical(Name=Value)

Description

ant = dipoleCylindrical creates a center-fed cylindrical dipole antenna with default property values. The default dimensions are chosen for an operating frequency of around 70 MHz.

ant = dipoleCylindrical(Name=Value) sets properties using one or more name-value arguments. Name is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as Name1=Value1,...,NameN=ValueN. Properties that you do not specify, retain their default values.

For example, ant = dipoleCylindrical(Radius=0.04) creates a cylindrical dipole antenna with radius of 0.04 meters.

Properties

Length — Length of dipole

2 (default) | positive scalar

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

Example: 3

Data Types: double

Radius — Radius of dipole

0.025 (default) | positive scalar

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

Example: 0.05

Data Types: double

FeedOffset — Signed distance from center along z-axis

0 (default) | real-valued scalar

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

Example: -0.2

Data Types: double

ClosedEnd — Determines if dipole ends are closed with cap

0 (default) | 1

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: 1

Data Types: double

Conductor — Type of metal material

metal("PEC") (default) | metal object

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

Example: metal("Copper")

Tilt — Tilt angle of antenna

0 (default) | scalar | vector

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

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector | 2-by-3 matrix | "X" | "Y" | "Z"

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

Load — Lumped elements

[1x1 lumpedElement] (default) | lumpedElement object

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

Example: Load=lumpedElement(Impedance=75)

Example: antenna.Load = lumpedElement(Impedance=75)

Object Functions

axialRatio	Calculate and plot axial ratio of antenna or array
bandwidth	Calculate and plot absolute bandwidth of antenna or array
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	Calculate and plot radiation efficiency of antenna or array
EHfields	Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
feedCurrent	Calculate current at feed for antenna or array
impedance	Calculate and plot 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
msiwrite	Write antenna or array analysis data to MSI planet file
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
peakRadiation	Calculate and mark maximum radiation points of antenna or array on radiation pattern
rcs	Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequency	Calculate and plot resonant frequency of antenna
returnLoss	Calculate and plot return loss of antenna or scan return loss of array
show	Display antenna, array structures, shapes, or platform
sparameters	Calculate S-parameters for antenna or array
stlwrite	Write mesh information to STL file
strip2cylinder	Calculate equivalent radius approximation for strip
vswr	Calculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Examples

Create Default Cylindrical Dipole Antenna and Plot Radiation Pattern

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)

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

pattern(ant,70e6)

Impedance of Cylindrical Dipole Antenna

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))

Compare Current Distribution of Open- and Close-ended Cylindrical Dipole Antennas

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

antOpenEnded = dipoleCylindrical(Radius=0.1);
antClosedEnded = dipoleCylindrical(Radius=0.1, ClosedEnd=1);

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

iOpenEnded  = current(antOpenEnded,70e6)

iOpenEnded = 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(antOpenEnded,70e6)

iClosedEnded = current(antClosedEnded,70e6)

iClosedEnded = 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 - 0.0010i  -0.0180 - 0.0011i  -0.0180 - 0.0010i  -0.0180 - 0.0010i  -0.0180 - 0.0011i  -0.0180 - 0.0010i  -0.0180 - 0.0011i  -0.0180 - 0.0010i  -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

current(antClosedEnded,70e6)

More About

Parametric Analysis Guidelines

To understand how the properties of the dipoleCylindrical antenna object influence the antenna design, use these parametric analysis guidelines.

• To increase the operating frequency, decrease the Length of the dipoleCylindrical antenna.

• To increase the gain, increase the Length of the dipoleCylindrical antenna object.

• To increase the bandwidth, increase the Radius of the dipoleCylindrical antenna object.

References

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

Version History

Introduced in R2021a