Create cavity-backed antenna
cavity object is a cavity-backed antenna located on the
xyz- plane. The default cavity antenna has a dipole as an
exciter. The feed point is on the exciter.
creates a cavity backed
antenna located on the X-Y-Z plane. By default, the dimensions are chosen
for an operating frequency of 1 GHz.
c = cavity
cavity-backed antenna, with additional Properties specified by one or more name–value
c = cavity(Name=Value)
Name is the property name and
Value is the corresponding value. You can specify
several name-value arguments in any order as
ValueN. Properties not
specified retain their default values.
Exciter — Antenna or array to use as exciter
dipole (default) | antenna object | array object | empty array
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 Toolbox™ antenna or array element as an exciter. To create the cavity backing structure without the exciter, specify this property as an empty array.
Substrate — Type of dielectric material
'Air' (default) | dielectric object
Type of dielectric material used as a substrate, specified as a dielectric
object. For more information see,
dielectric. For more
information on dielectric substrate meshing, see Meshing.
The substrate dimensions must be equal to the ground plane dimensions.
Length — Length of rectangular cavity along x-axis
0.2000 (default) | scalar
Length of the rectangular cavity along the x-axis, specified as a scalar in meters.
Width — Width of rectangular cavity along y-axis
0.2000 (default) | scalar
Width of the rectangular cavity along the y-axis, specified as a scalar in meters.
Height — Height of rectangular cavity along z-axis
0.0750 (default) | scalar
Height of the rectangular cavity along the z-axis, specified as a scalar in meters.
Spacing — Distance between exciter and base of cavity
0.0750 (default) | scalar
Distance between the exciter and the base of the cavity, specified as a scalar in meters.
Conductor — Type of metal material
"PEC" (default) | metal object
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
metal. For more information on metal conductor meshing, see
Load — Lumped elements
[1x1 lumpedElement] (default) | lumped element object
Lumped elements added to the antenna feed, specified as a lumped element
object. For more information, see
EnableProbeFeed — Create probe feed from backing structure to exciter
0 (default) |
Create probe feed from backing structure to exciter, specified as a
1. By default, probe feed is
Tilt — Tilt angle of antenna
0 (default) | scalar | vector
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.
TiltAxis=[0 1 0;0 1 1]
tilts the antenna at 90 degrees about the two axes defined by the
wireStack antenna object
only accepts the dot method to change its properties.
TiltAxis — Tilt axis of antenna
[1 0 0] (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates |
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.
TiltAxis=[0 1 0]
TiltAxis=[0 0 0;0 1 0]
TiltAxis = 'Z'
|Display antenna, array structures or shapes|
|Display information about antenna or array|
|Axial ratio of antenna|
|Beamwidth of antenna|
|Charge distribution on antenna or array surface|
|Current distribution on antenna or array surface|
|Design prototype antenna or arrays for resonance around specified frequency|
|Radiation efficiency of antenna|
|Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays|
|Input impedance of antenna; scan impedance of array|
|Mesh properties of metal, dielectric antenna, or array structure|
|Change mesh mode of antenna structure|
|Optimize antenna or array using SADEA optimizer|
|Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array|
|Azimuth pattern of antenna or array|
|Elevation pattern of antenna or array|
|Calculate and plot radar cross section (RCS) of platform, antenna, or array|
|Return loss of antenna; scan return loss of array|
|Calculate S-parameter for antenna and antenna array objects|
|Voltage standing wave ratio of antenna|
Create and View Cavity-Backed Antenna
Create and view a cavity-backed dipole antenna with 30 cm length, 25 cm width, 7.5 cm height and spaced 7.5 cm from the bowtie for operation at 1 GHz.
c = cavity(Length=30e-2,Width=25e-2,Height=7.5e-2,Spacing=7.5e-2); show(c)
Radiation Pattern of Cavity-Backed Antenna
Create a cavity-backed antenna using a dielectric substrate 'FR4'.
d = dielectric('FR4'); c = cavity(Length=30e-2,Width=25e-2,Height=20.5e-3,Spacing=7.5e-3,... Substrate=d)
c = cavity with properties: Exciter: [1x1 dipole] Substrate: [1x1 dielectric] Length: 0.3000 Width: 0.2500 Height: 0.0205 Spacing: 0.0075 EnableProbeFeed: 0 Conductor: [1x1 metal] Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement]
Plot the radiation pattern of the antenna at a frequency of 1 GHz.
Create Rectangular Array with Cavity Backing Structure
Create a rectangular array of E-shaped patch antenna.
rectArr = rectangularArray(Element=patchMicrostripEnotch,RowSpacing=0.03,ColumnSpacing=0.03);
Create a cavity-backed antenna with rectangular array exciter.
ant = cavity(Exciter=rectArr)
ant = cavity with properties: Exciter: [1x1 rectangularArray] Substrate: [1x1 dielectric] Length: 0.2000 Width: 0.2000 Height: 0.0750 Spacing: 0.0750 EnableProbeFeed: 0 Conductor: [1x1 metal] Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement]
Create Fractal Carpet Antenna with Cavity Backing structure
Create and visualize a cavity-backed fractal carpet antenna
e = fractalCarpet(Substrate=dielectric('FR4')); ant = cavity(Exciter=e)
ant = cavity with properties: Exciter: [1x1 fractalCarpet] Substrate: [1x1 dielectric] Length: 0.2000 Width: 0.2000 Height: 0.0750 Spacing: 0.0750 EnableProbeFeed: 0 Conductor: [1x1 metal] Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement]
Analyze Cavity Structure Using Plane Wave Excitation
This example shows how to create and analyze a cavity-shaped backing structure without an exciter element using
Create Cavity Antenna
Create a cavity antenna operating at 1 GHz using the
design function and the
cavity element from the antenna catalog. Display the antenna.
f = 1e9; ant = design(cavity,f); figure show(ant)
Derive Backing Structure
Derive the backing structure from the cavity antenna by specifying the
'Exciter' property as an empty array.
ant.Exciter = 
ant = cavity with properties: Exciter:  Substrate: [1x1 dielectric] Length: 0.1690 Width: 0.1690 Height: 0.0634 Spacing: 0.0634 EnableProbeFeed: 0 Conductor: [1x1 metal] Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement]
Display the backing structure.
Mesh Backing Structure
Mesh the cavity structure with a maximum edge length of 10 mm.
Plot Directivity Pattern
Use the cavity backing structure as a receiver element in a plane wave excitation environment and plot its directivity at 1 GHz.
pw = planeWaveExcitation(Element=ant); figure pattern(pw,f)
 Balanis, Constantine A. Antenna Theory: Analysis and Design. Fourth edition. Hoboken, New Jersey: Wiley, 2016.
Introduced in R2015a