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Create Gregorian antenna

Since R2019b


The gregorian object creates a horn conical fed Gregorian antenna. A Gregorian antenna is a parabolic antenna. In this antenna, the feed antenna is mounted at or behind the surface of the main parabolic reflector and aimed at the sub-reflector. This antenna is used in radio telescopes and communication satellites. For more information see, Architecture of Gregorian Antenna.




ant = gregorian creates a horn conical fed Gregorian antenna with a default operating frequency of 18.48 GHz. This antenna gives maximum gain when operated at 18.3 GHz.

ant = gregorian(Name=Value) creates a Gregorian 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, ant = gregorian(FocalLength=[0.4 0.22]) creates a Gregorian antenna with the main reflector of focal length 0.4 m and the sub-reflector of focal length 0.22 m.


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Exciter antenna or array type, specified as an antenna object, an array object, measured pattern data of an antenna, 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: measuredAntenna

Example: []

Radius of the main and sub-reflector, specified as a two-element vector with each element unit in meters. The first element specifies the radius of the main reflector, and the second element specifies the radius of the sub-reflector.

Example: Radius=[0.4 0.2]

Data Types: double

Focal length of the main and sub-reflector, specified as a two-element vector with each element unit in meters. The first element specifies the focal length of the main reflector, and the second element specifies the focal length of the subreflector.

Example: FocalLength=[0.35 0.2]

Data Types: double

Lumped elements added to the antenna feed, specified as a lumped element 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=lumpedelement. lumpedelement is the object for the load created using lumpedElement.

Example: 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 degrees about the two axes defined by the vectors.


The wireStack antenna object only accepts the dot method to change its properties.

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'.

For more information, see Rotate Antennas and Arrays.

Example: TiltAxis=[0 1 0]

Example: TiltAxis=[0 0 0;0 1 0]

Example: TiltAxis = 'Z'

Data Types: double

Solver for antenna analysis, specified as a string. Default solver is "MoM-PO"(Method of Moments-Physical Optics hybrid). Other supported solvers are: "MoM" (Method of Moments), "PO" (Physical optics) or "FMM" (Fast Multipole Method).

Example: SolverType="MoM"

Data Types: string

Object Functions

showDisplay antenna, array structures or shapes
solverAccess FMM solver for electromagnetic analysis
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on antenna or array surface
currentCurrent distribution on antenna or array surface
designDesign prototype antenna or arrays for resonance around 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, dielectric antenna, or array structure
meshconfigChange mesh mode of antenna structure
optimizeOptimize antenna or array using SADEA optimizer
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
rcsCalculate and plot radar cross section (RCS) of platform, antenna, or array
returnLossReturn loss of antenna; scan return loss of array
sparametersCalculate S-parameter for antenna and antenna array objects
vswrVoltage standing wave ratio of antenna


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Create and view a default Gregorian antenna.

ant = gregorian
ant = 
  gregorian with properties:

        Exciter: [1×1 hornConical]
         Radius: [0.3175 0.0330]
    FocalLength: [0.2536 0.1416]
           Tilt: 0
       TiltAxis: [1 0 0]
           Load: [1×1 lumpedElement]


Plot the radiation pattern of the antenna at 18.48 GHz.


Create an array of vee dipole antennas.

e = dipoleVee(ArmLength=[0.03 0.03],Width=0.01);
arr = rectangularArray(Element=e,RowSpacing=0.05,ColumnSpacing=0.05);

Create a Gregorian antenna with rectangular array as exciter

ant = gregorian(Exciter=arr);

Figure contains an axes object. The axes object with title gregorian antenna element, xlabel x (mm), ylabel y (mm) contains 13 objects of type patch, surface. These objects represent PEC, feed.

More About

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Version History

Introduced in R2019b