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reflectorGrid

Create grid reflector-backed antenna

Since R2020b

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Description

The default reflectorGrid object creates a grid reflector-backed antenna resonating around 1 GHz. The grid reflector uses a grid of parallel wires or bars oriented in one direction. Grid reflectors can be used as high-gain antennas in point-to-point communications.

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

Creation

Syntax

ant = reflectorGrid
ant = reflectorGrid(Name=Value)

Description

ant = reflectorGrid creates a grid reflector-backed antenna object with default property values. The default antenna object has a dipole as an exciter with the feed point located at the origin on the xy-plane. The default dimensions are chosen for an operating frequency of around 1 GHz.

example

ant = reflectorGrid(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, reflectorGrid(GroundPlaneWidth=0.6) creates a grid reflector with a width of 0.6 meters. You can specify multiple name-value pairs.

example

Properties

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Exciter antenna or array type, specified as either:

  • Antenna object from the catalog (except reflector type, cavity type and platform-installed antennas)

  • Array object from the catalog (except conformal and infinite arrays)

  • Custom antennas: customAntennaGeometry, customAntennaMesh, customAntenna

  • Empty array

To create the reflector backing structure without an exciter, specify this property as an empty array.

Example: horn

Example: linearArray(Element=patchMicrostrip)

Example: customAntenna

Example: []

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

Example: 0.259

Data Types: double

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

Example: 0.6

Data Types: double

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

Example: 0.6

Data Types: double

Type of the grid used in the reflector, specified as either one of the following:

  • "H" — grids are arranged horizontally in the reflector.

  • "V" — grids are arranged vertically in the reflector.

  • "HV" or "VH" — grids are arranged both horizontally and vertically in the reflector.

Example: "H"

Data Types: char

Distance between the two grid cells, specified as a positive scalar in meters.

Example: 0.018

Data Types: double

Width of each grid cell, specified as a positive scalar in meters.

Example: 0.3

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

axialRatioCalculate and plot axial ratio of antenna or array
bandwidthCalculate and plot absolute bandwidth of antenna or array
beamwidthBeamwidth of antenna
currentCurrent distribution on antenna or array surface
chargeCharge distribution on antenna or array surface
designDesign prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
efficiencyCalculate and plot radiation efficiency of antenna or array
EHfieldsElectric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
feedCurrentCalculate current at feed for antenna or array
impedanceCalculate and plot input impedance of antenna or scan impedance of array
infoDisplay information about antenna, array, or platform
memoryEstimateEstimate memory required to solve antenna or array mesh
meshMesh properties of metal, dielectric antenna, or array structure
meshconfigChange meshing mode of antenna, array, custom antenna, custom array, or custom geometry
msiwriteWrite antenna or array analysis data to MSI planet file
numGridsToSpacingCalculate grid spacing in for reflectorGrid object
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
peakRadiationCalculate and mark maximum radiation points of antenna or array on radiation pattern
rcsCalculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequencyCalculate and plot resonant frequency of antenna
returnLossCalculate and plot return loss of antenna or scan return loss of array
showDisplay antenna, array structures, shapes, or platform
sparametersCalculate S-parameters for antenna or array
stlwriteWrite mesh information to STL file
vswrCalculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Examples

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Open Live Script

Create and view a grid reflector-backed antenna object with default properties.

ant = reflectorGrid;
show(ant)

Figure contains an axes object. The axes object with title reflectorGrid 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 at 1 GHz.

pattern(ant,1e9)

Figure contains 2 axes objects and other objects of type uicontrol. Axes object 1 contains 5 objects of type patch, surface. Hidden axes object 2 contains 18 objects of type surface, line, text, patch.

Open Live Script

Create and view a grid reflector-backed biquad antenna with an arm length of 0.01 meters.

b = biquad(ArmLength=0.01);
h = reflectorGrid(Exciter=b);
show(h)

Figure contains an axes object. The axes object with title reflectorGrid 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 at 0.6 GHz.

pattern(h,0.6e9)

Figure contains 2 axes objects and other objects of type uicontrol. Axes object 1 contains 5 objects of type patch, surface. Hidden axes object 2 contains 18 objects of type surface, line, text, patch.

Open Live Script

Create and view grid reflector-baked dipole blade antenna.

d = dipoleBlade(Length=0.1,TaperLength=0.05,FeedGap=0.002);
h = reflectorGrid(Exciter=d);
show(h)

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

Change the grid type from "HV" to "H".

h.GridType = "H";

View the antenna with grid type "H".

show(h)

Figure contains an axes object. The axes object with title reflectorGrid 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 GHz.

pattern(h,1e9)

Figure contains 2 axes objects and other objects of type uicontrol. Axes object 1 contains 5 objects of type patch, surface. Hidden axes object 2 contains 18 objects of type surface, line, text, patch.

Open Live Script

Create a rectangular array of cylindrical dipole antennas.

d = dipoleCylindrical(Length=0.2,Radius=0.005);
arr = rectangularArray(Element=d,Size=[4 4],RowSpacing=0.029,ColumnSpacing=0.029);

Create a grid reflector-backed rectangular array.

ant = reflectorGrid(Exciter=arr,Spacing=0.2)
ant = 
  reflectorGrid with properties:

              Exciter: [1x1 rectangularArray]
              Spacing: 0.2000
    GroundPlaneLength: 0.2000
     GroundPlaneWidth: 0.2000
             GridType: 'HV'
          GridSpacing: 0.0180
            GridWidth: 0.0220
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


show(ant)

Figure contains an axes object. The axes object with title reflectorGrid antenna element, xlabel x (mm), ylabel y (mm) contains 35 objects of type patch, surface. These objects represent PEC, feed.

Open Live Script

Create and visualize a grid reflector-backed antipodal Vivaldi antenna.

ant = reflectorGrid(Exciter=vivaldiAntipodal)
ant = 
  reflectorGrid with properties:

              Exciter: [1x1 vivaldiAntipodal]
              Spacing: 0.1750
    GroundPlaneLength: 0.2000
     GroundPlaneWidth: 0.2000
             GridType: 'HV'
          GridSpacing: 0.0180
            GridWidth: 0.0220
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


show(ant)

Figure contains an axes object. The axes object with title reflectorGrid antenna element, xlabel x (mm), ylabel y (mm) contains 7 objects of type patch, surface. These objects represent PEC, feed, RO4003C.

Open Live Script

This example shows how to create and analyze a planar reflector grid structure without any exciter element, using planeWaveExcitation.

Create default reflector grid antenna

Create a reflector grid antenna operating at 1 GHz using the design function and the reflectorGrid element from the antenna catalog, and view it.

f=1e9;
ant=design(reflectorGrid,f);
figure;
show(ant)

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

Derive backing structure

Derive the backing structure from this reflector grid antenna by assigning empty value to the 'Exciter' property and view it.

ant.Exciter=[]
ant = 
  reflectorGrid with properties:

              Exciter: []
              Spacing: 0.1749
    GroundPlaneLength: 0.2000
     GroundPlaneWidth: 0.2000
             GridType: 'HV'
          GridSpacing: 0.0180
            GridWidth: 0.0220
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


figure;
show(ant)

Figure contains an axes object. The axes object with title reflectorGrid antenna element, xlabel x (mm), ylabel y (mm) contains 2 objects of type patch. This object represents PEC.

Mesh reflector grid

Mesh the grid structure with a maximum edge length of 10 mm.

figure;
mesh(ant,MaxEdgeLength=10e-3)

Figure contains an axes object and an object of type uicontrol. The axes object with title Metal mesh, xlabel x (m), ylabel y (m) contains an object of type patch. This object represents PEC.

Plot surface current distribution

Use planewave excitation to excite the grid structure and plot the surface current distribution at 1 GHz.

pw=planeWaveExcitation(Element=ant,Direction=[0 0 -1],Polarization=[1 0 0])
pw = 
  planeWaveExcitation with properties:

         Element: [1x1 reflectorGrid]
       Direction: [0 0 -1]
    Polarization: [1 0 0]
      SolverType: 'MoM'


figure;
current(pw,f,Scale="log10")

Figure contains an axes object. The axes object with title Current distribution (log10), xlabel x (m), ylabel y (m) contains 3 objects of type patch.

References

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

Version History

Introduced in R2020b

See Also

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