Create circular reflector-backed antenna


Use the reflectorCircular object to create a circular reflector-backed antenna. By default the exciter is a dipole. The dimensions are chosen for an operating frequency of 1 GHz.




rc = reflectorCircular creates a circular reflector backed antenna.


rc = reflectorCircular(Name,Value) sets properties using one or more name-value pair. For example, rc = reflectorCircular('Radius',0.2) creates a circular reflector of radius 0.2 m. Enclose each property name in quotes.


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Antenna type used as an exciter, specified as an object. Except for reflector and cavity antenna elements, you can use all the single elements in the Antenna Toolbox™ as an exciter.

Example: 'Exciter',spiralEquiangular

Example: rc.Exciter = spiralEquiangular

Radius of reflector, specified as a scalar in meters.

Example: 'Radius',0.2

Example: rc.Radius = 0.2

Data Types: double

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

Example: 'Spacing',7.5e-2

Example: rc.Spacing = 7.5e-2

Data Types: double

Type of dielectric material used as a substrate, specified as an object. For more information see, dielectric. For more information on dielectric substrate meshing, see Meshing.


The substrate dimensions must be equal to the groundplane dimensions.

Example: d = dielectric('FR4'); 'Substrate',d

Example: d = dielectric('FR4'); rc.Substrate = d

Create probe feed from backing structure to exciter, specified as 0 or 1 or a scalar. By default, probe feed is not enabled.

Example: 'EnableProbeFeed',1

Example: rc.EnableProbeFeed = 1

Data Types: double | logical

Lumped elements added to the antenna feed, specified as a lumped element object handle. You can add a load anywhere on the surface of the antenna. By default, the load is at the origin. For more information, see lumpedElement.

Example: 'Load',lumpedelement. lumpedelement is the object handle for the load created using lumpedElement.

Example: rc.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 degree about two axes, defined by vectors.

Data Types: double

Tilt axis of the antenna, specified as:

  • Three-element vectors of Cartesian coordinates in meters. In this case, each 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: ant.TiltAxis = 'Z'

Object Functions

showDisplay antenna or array structure; Display shape as filled patch
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on metal or dielectric antenna or array surface
currentCurrent distribution on metal or dielectric antenna or array surface
designDesign prototype antenna or arrays for resonance at specified frequency
EHfieldsElectric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedanceInput impedance of antenna; scan impedance of array
meshMesh properties of metal or dielectric antenna or array structure
meshconfigChange mesh mode of antenna structure
patternRadiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
patternAzimuthAzimuth pattern of antenna or array
patternElevationElevation pattern of antenna or array
returnLossReturn loss of antenna; scan return loss of array
sparametersS-parameter object
vswrVoltage standing wave ratio of antenna


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Create and view a default circular reflector backed antenna.

rc = reflectorCircular
rc = 
  reflectorCircular with properties:

              Exciter: [1x1 dipole]
            Substrate: [1x1 dielectric]
    GroundPlaneRadius: 0.1000
              Spacing: 0.0750
      EnableProbeFeed: 0
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


Create an equiangular spiral backed by a circular reflector.

ant = reflectorCircular('Exciter',spiralEquiangular,'GroundPlaneRadius',  ...
          0.02,'Spacing', 0.01);

Plot the radiation pattern of the antenna at 4 GHz.


Introduced in R2017b