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reflectorCylindrical

Create cylindrical reflector-backed antenna

Since R2020b

Description

The reflectorCylindrical antenna object creates a cylindrical reflector-backed antenna. The cylindrical shape of the reflector allows you to focus the signal to the antenna surface. Cylindrical reflectors are widely used as high-gain apertures fed with line sources and in airborne navigational antennas where sharp azimuthal beams and wide-angle vertical coverage is required.

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

Creation

Description

example

ant = reflectorCylindrical creates a cylindrical reflector-backed antenna. The default cylindrical reflector antenna object has an exciter as a center-fed dipole located on the X-Y plane and the dimensions are chosen for an operating frequency of around 1 GHz.

example

ant = reflectorCylindrical(Name=Value) creates a cylindrical reflector antenna, with additional Properties specified by 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 not specified retain their default values.

For example, reflectorCylindrical(GroundPlaneWidth=0.21) creates a cylindrical reflector with a width of 0.21 meters.

Properties

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Exciter antenna or array type, specified as an antenna object, an array object, or an empty array. Except for reflector and cavity antenna elements, you can use any Antenna Toolbox™ antenna or array element as an exciter. To create the reflector backing structure without the exciter, specify this property as an empty array.

Example: dipole

Example: linearArray(Element=patchMicrostrip)

Example: []

Reflector length along X-axis, specified as a positive scalar in meters.

Example: 0.6

Data Types: double

Reflector width along Y-axis, specified as a positive scalar in meters.

Example: 0.4

Data Types: double

Distance between reflector and exciter, specified as a scalar in meters.

Example: 0.059

Data Types: double

Perpendicular distance between the ground plane and the aperture of the cylindrical reflector, specified as a positive scalar in meters.

Example: 0.09

Note

Depth should be less than or equal to half of the GroundPlaneLength.

Data Types: double

Flag to enable the probe feed, specified as 0 or 1. Setting the flag to 0 disables the probe feed, and setting the flag to 1 enables it.

Example: 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: metal("Copper")

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

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

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. For more information, see lumpedElement.

Example: Load=lumpedelements, where lumpedelements is the load added to the antenna feed.

Example: lumpedElement(Impedance=75)

Object Functions

showDisplay antenna, array structures, shapes, or platform
impedanceInput impedance of antenna or scan impedance of array
sparametersCalculate S-parameters for antennas and antenna arrays
returnLossReturn loss of antenna or scan return loss of array
vswrVoltage standing wave ratio (VSWR) of antenna or array element
optimizeOptimize antenna or array using SADEA optimizer
patternPlot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array
patternAzimuthAzimuth plane radiation pattern of antenna or array
patternElevationElevation plane radiation pattern of antenna or array
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
currentCurrent distribution on antenna or array surface
chargeCharge distribution on antenna or array surface
efficiencyRadiation efficiency of antenna
EHfieldsElectric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
meshMesh properties of metal, dielectric antenna, or array structure
designDesign prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
rcsCalculate and plot radar cross section (RCS) of platform, antenna, or array

Examples

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Create a cylindrical reflector antenna object with default properties.

ant = reflectorCylindrical;

View the antenna object.

show(ant)

Figure contains an axes object. The axes object with title reflectorCylindrical antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Create a reflectorCylindrical antenna object with a rounded bow-tie dipole antenna as an exciter.

b = bowtieRounded(Length=96e-3,Tilt=90,TiltAxis=[0 1 0]);
r = reflectorCylindrical(Exciter=b,Spacing=100e-3);

View the antenna object.

figure
show(r)

Figure contains an axes object. The axes object with title reflectorCylindrical antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Plot the radiation pattern at 1.5 GHz.

figure
pattern(r,1.5e9)

Figure contains an axes object and other objects of type uicontrol. The axes object contains 5 objects of type patch, surface.

Enable the probe feed for the reflectorCylindrical antenna object.

re = reflectorCylindrical(Exciter=b,Spacing=100e-3,EnableProbeFeed=1);

View the antenna object with the probe feed enabled.

figure
show(re)

Figure contains an axes object. The axes object with title reflectorCylindrical antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Plot the radiation pattern of the antenna object at 1.5 GHz with the probe feed enabled.

figure
pattern(re,1.5e9)

Figure contains an axes object and other objects of type uicontrol. The axes object contains 5 objects of type patch, surface.

Create a linear array of crossed dipole antenna.

d = dipoleCrossed(Tilt=90,TiltAxis=[0 1 0]);
la = linearArray(Element=d,NumElements=4,ElementSpacing=0.05,Tilt=90,TiltAxis=[0 0 1]);

Create a cylindrical reflector backed array.

ant = reflectorCylindrical(Exciter=la,Tilt=90)
ant = 
  reflectorCylindrical with properties:

              Exciter: [1x1 linearArray]
    GroundPlaneLength: 0.2000
     GroundPlaneWidth: 0.2000
              Spacing: 0.0750
                Depth: 0.0750
      EnableProbeFeed: 0
            Conductor: [1x1 metal]
                 Tilt: 90
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(ant)

Figure contains an axes object. The axes object with title reflectorCylindrical antenna element, xlabel x (mm), ylabel y (mm) contains 19 objects of type patch, surface. These objects represent PEC, feed.

Create a cylindrical reflector-backed Minkowski's loop fractal antenna.

e = fractalIsland(Substrate=dielectric("Teflon"),Tilt=90,TiltAxis=[0 0 1]);
ant = reflectorCylindrical(Exciter=e)
ant = 
  reflectorCylindrical with properties:

              Exciter: [1x1 fractalIsland]
    GroundPlaneLength: 0.2000
     GroundPlaneWidth: 0.2000
              Spacing: 0.0750
                Depth: 0.0750
      EnableProbeFeed: 0
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(ant)

Figure contains an axes object. The axes object with title reflectorCylindrical antenna element, xlabel x (mm), ylabel y (mm) contains 7 objects of type patch, surface. These objects represent PEC, feed, Teflon.

References

[1] Balanis, Constantine A. Antenna Theory: Analysis and Design. 3rd ed. Hoboken, NJ: John Wiley, 2005.

Version History

Introduced in R2020b