reflectorParabolic

Create parabolic reflector antenna

Description

The default reflectorParabolic object creates a parabolic reflector antenna resonating around 10 GHz. Parabolic reflector antennas are electrically large structures and are at least 10 wavelengths in diameter. These reflectors are used in TV antennas and satellite communications, for example.

Creation

Syntax

ant = reflectorParabolic

ant = reflectorParabolic(PropertyName=Value)

Description

ant = reflectorParabolic creates a dipole-fed parabolic reflector antenna with default property values. The default dimensions are chosen for an operating frequency of around 10 GHz. The reflector is 10λ in diameter, where λ corresponds to the value of wavelength.

ant = reflectorParabolic(PropertyName=Value) sets properties using one or more name–value arguments. PropertyName is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as PropertyName1=Value1,...,PropertyNameN=ValueN. Properties that you do not specify, retain their default values.

For example, ant = reflectorParabolic(FocalLength=0.5) creates a parabolic reflector antenna with 0.5 meters focal length.

Properties

Exciter — Antenna or array type used as exciter

dipole (default) | antenna object | array object | custom antenna object | measuredAntenna object | empty array

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

• Measured pattern data of an antenna or array: measuredAntenna

• 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: measuredAntenna

Example: []

Radius — Radius of parabolic reflector

0.1500 (default) | positive scalar

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

Example: 0.22

Data Types: double

FocalLength — Focal length of parabolic reflector

0.0750 (default) | positive scalar

Focal length of the parabolic reflector, specified as a positive scalar in meters.

Example: 0.0850

Data Types: double

FeedOffset — Signed distance from focus

[0 0 0] (default) | three-element vector

Signed distance from the focus of the parabolic reflector, specified as a three-element vector in meters. By default, the antenna exciter is at the focus of the parabola. Using the FeedOffset property, you can place the exciter anywhere on the parabola.

Example: [0.0850 0 0]

Data Types: double

Conductor — Type of metal

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")

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: lumpedElement(Impedance=75)

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

SolverType — Solver for antenna analysis

"MoM-PO" (default) | "MoM" | "PO" | "FMM"

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

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
design	Create antenna, array, or AI-based antenna resonating at specified frequency
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	Generate and view mesh for antennas, arrays, and custom shapes
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 and array catalog elements using SADEA or TR-SADEA algorithm
pattern	Plot radiation pattern of antenna, array, or embedded element of 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
solver	Access FMM solver settings for electromagnetic analysis
sparameters	Calculate S-parameters for antenna or array
stlwrite	Write mesh information to STL file
vswr	Calculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Examples

Default Parabolic Reflector and Radiation Pattern

Create and view a default parabolic reflector antenna.

ant = reflectorParabolic

ant = 
  reflectorParabolic with properties:

        Exciter: [1×1 dipole]
         Radius: 0.1500
    FocalLength: 0.0750
     FeedOffset: [0 0 0]
           Tilt: 0
       TiltAxis: [1 0 0]
           Load: [1×1 lumpedElement]
     SolverType: 'MoM-PO'

show(ant)

Plot the radiation pattern of the parabolic reflector at 10 GHz.

pattern(ant,10e9)

Create Parabolic Reflector-Backed Circular Array of Equiangular Spiral Antenna

Create a circular array of equiangular spiral antennas.

circA = circularArray(Element=spiralEquiangular,Radius=0.1);

Create a parabolic reflector-backed antenna.

ant = reflectorParabolic(Exciter=circA)

ant = 
  reflectorParabolic with properties:

        Exciter: [1×1 circularArray]
         Radius: 0.1500
    FocalLength: 0.0750
     FeedOffset: [0 0 0]
           Tilt: 0
       TiltAxis: [1 0 0]
           Load: [1×1 lumpedElement]
     SolverType: 'MoM-PO'

show(ant)

Custom Parabolic Reflector Antenna with Hole

This example shows how to create a hole in a parabolic reflector antenna for a mounting structure.

Create a mesh for the reflectorParabolic antenna catalog object. Use the mesh points and triangles data to create a triangulation object. Create a parabolic reflector shape from this triangulation object using the shape.Custom3D object.

p = reflectorParabolic;
m = mesh(p,MaxEdgeLength=0.05);
pts1 = m.Points';
tri1 = m.Triangles';
tp = triangulation(tri1(:,1:3),pts1);
pShape = shape.Custom3D(tp);

Create a cylinder to punch a hole in the parabolic reflector shape.

h = p.Exciter.Length;
r1 = 0.2*p.Radius;
hole = shape.Cylinder(Radius=r1,Height=h);
pShapeWithHole = pShape - hole;

Create the custom parabolic reflector antenna using the customAntenna object and add a feed to it using the createFeed function. View the custom parabolic reflector antenna.

c = customAntenna(Shape=pShapeWithHole);
createFeed(c,[0,0,26],1);
figure
show(c)
view([54 52])
title("Custom Parabolic Reflector Antenna")

View the exciter element.

figure
show(c)
zoom(15)
view([-32.36 72.36])

figure
show(c)
view([0 90])
zoom(15)
title("Exciter Element")

Version History

Introduced in R2018b