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cavityCircular

Create circular cavity-backed antenna

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Description

The default circularCavity object creates a circular cavity-backed antenna resonating around 833 MHz. By default, a dipole element is used as an exciter for this antenna. The feed point is located on the exciter.

Labeled geometry of the circular cavity-backed antenna..

Creation

Syntax

c = cavityCircular
c = cavityCircular(Name=Value)

Description

c = cavityCircular creates a circular cavity-backed antenna with default property values. The default dimensions are chosen for an operating frequency of around 833 MHz.

example

c = cavityCircular(Name=Value) creates a circular cavity-backed antenna, with 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, c = cavityCircular(Radius=0.2) creates a circular-cavity backed antenna with cavity radius of 0.2 m. and default values for other properties.

example

Properties

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Cavity radius, specified as a positive scalar in meters.

Example: 0.2

Data Types: double

Cavity height along z-axis, specified as a positive scalar in meters.

Example: 0.001

Data Types: double

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

Example: Exciter=horn

Example: Exciter=linearArray(Element=patchMicrostrip)

Example: Exciter=[]

Distance between the exciter and the base of the cavity, specified as a positive scalar in meters.

Example: 10e-2

Data Types: double

Type of dielectric material used as a substrate, specified as a dielectric object. You can choose any dielectric material from the DielectricCatalog or specify a dielectric material of your choice. The substrate dimensions must be equal to the ground plane dimensions. For more information on dielectric substrate meshing, see Meshing.

Example: dielectric("FR4")

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")

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: Load=lumpedElement(Impedance=75)

Example: antenna.Load = lumpedElement(Impedance=75)

Option to create probe feed from backing structure to exciter, specified as a numeric 0 or 1. Specify 0 to disable or 1 to enable the probe feed. By default, probe feed is disabled.

Example: 1

Data Types: double

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

Object Functions

axialRatioCalculate and plot axial ratio of antenna or array
bandwidthCalculate and plot absolute bandwidth of antenna or array
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 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
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 default circular cavity-backed antenna.

a = cavityCircular
a = 
  cavityCircular with properties:

            Exciter: [1x1 dipole]
          Substrate: [1x1 dielectric]
             Radius: 0.1000
             Height: 0.0750
            Spacing: 0.0750
    EnableProbeFeed: 0
          Conductor: [1x1 metal]
               Tilt: 0
           TiltAxis: [1 0 0]
               Load: [1x1 lumpedElement]


show(a)

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

Open Live Script

Create and view an equiangular spiral backed by a circular cavity. The cavity dimensions are:

Radius = 0.02 m

Height = 0.01 m

Spacing = 0.01 m

 ant = cavityCircular(Exciter=spiralEquiangular,Radius=0.02,   ...
          Height=0.01,Spacing=0.01);
 show(ant)

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

Open Live Script

Create a linear array of H-shaped patch microstrip antenna.

arr = linearArray(Element=patchMicrostripHnotch,ElementSpacing=0.04);

Create a circular cavity-backed antenna with linear array exciter.

ant = cavityCircular(Exciter=arr)
ant = 
  cavityCircular with properties:

            Exciter: [1x1 linearArray]
          Substrate: [1x1 dielectric]
             Radius: 0.1000
             Height: 0.0750
            Spacing: 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 cavityCircular antenna element, xlabel x (mm), ylabel y (mm) contains 10 objects of type patch, surface. These objects represent PEC, feed.

Open Live Script

Create and visualize a circular cavity-backed cylindrical dielectric resonator antenna.

e = draCylindrical;
ant = cavityCircular(Exciter=e)
ant = 
  cavityCircular with properties:

            Exciter: [1x1 draCylindrical]
          Substrate: [1x1 dielectric]
             Radius: 0.1000
             Height: 0.0750
            Spacing: 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 cavityCircular antenna element, xlabel x (mm), ylabel y (mm) contains 8 objects of type patch, surface. These objects represent PEC, feed, customdielectric.

Open Live Script

This example shows how to create a circular cavity structure as an element in a conformalArray and plot its surface current distribution.

Create Circular Cavity Antenna

Create a circular cavity antenna operating at 1 GHz using the design function and the cavityCircular element from the antenna catalog. Display the antenna.

f = 1e9;
lambda = 3e8/f;
ant = design(cavityCircular,f);
figure
show(ant)

Figure contains an axes object. The axes object with title cavityCircular 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 circular cavity backing structure from the cavity antenna by specifying the 'Exciter' property as an empty array. Display the backing structure.

ant.Exciter = [];
figure
show(ant)

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

Create Conformal Array

Create and display a conformal array with circular cavity as one of its elements.

ca = conformalArray;
ca.Reference = "origin";
ca.ElementPosition = [0 0 0; 0 0 0.25; 0 0 0.5];
ca.Element = {ca.Element{1} ant ca.Element{2}};
figure
show(ca)

Figure contains an axes object. The axes object with title conformalArray of antennas, xlabel x (mm), ylabel y (mm) contains 8 objects of type patch, surface. These objects represent PEC, feed.

Plot Surface Current Distribution

Calculate the current at the feed location and plot the surface current distribution of the conformal array at 1 GHz.

If = feedCurrent(ca,f)
If = 1×2 complex

   0.0023 - 0.0005i   0.0029 + 0.0007i


figure
current(ca,f,Scale="log10")

Figure contains an axes object. The axes object with title Current distribution (log10), xlabel x (m), ylabel y (m) contains 7 objects of type patch.

Version History

Introduced in R2017b

See Also

Objects

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