fractalSnowflake

Create fractal Koch snowflake antenna

Description

The fractalSnowflake object creates a Koch snowflake fractal antenna. These fractal antennas are used in mobile phone, Wi-Fi®, and radar applications.

A fractal antenna uses a fractal, a self-similar design that is repeated in different dimensions so as to maximize effective the length or increase the perimeter of the material that transmits or receives electromagnetic radiation. This makes the fractal antennas compact and therefore suitable for use in small and complex circuits. Fractal antennas also have higher input impedance or resistance due to their length or increased perimeter.

All fractal antennas are printed structures that are etched on a dielectric substrate.

Creation

Description

example

ant = fractalSnowflake creates a Koch’s snowflake fractal antenna. The default fractal is centered at the origin, and the number of iterations is set to 2. The length of the fractal is for an operating frequency of 4.15 GHz.

example

ant = fractalSnowflake(Name,Value) sets properties using one or more name-value pairs. For example, ant = fractalSnowflake('Numiterations',4) creates a Koch's snowflake with four iterations.

Properties

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Number of iterations performed on the fractal antenna, specified as a scalar integer.

Example: 'NumIterations',4

Example: ant.NumIterations = 4

Data Types: double

Length of the side of the equilateral triangle in fractal snowflake, specified as a positive scalar integer in meters.

Example: 'Length',0.5000

Example: ant.Length = 0.5000

Data Types: double

Height of the fractal from the ground plane along Z-axis, specified as a positive scalar integer in meters.

Example: 'Height',0.0050

Example: ant.Height = 0.0050

Data Types: double

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

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

Example: ant= fractalSnowflake('Substrate',dielectric('Name','RO4003C','EpsilonR',3.38,'LossTangent',0.0027,'Thickness',0.508e-3))

Data Types: string | char

Length of the ground plane, specified as a positive scalar integer in meters.

Example: 'GroundPlaneLength',0.0550

Example: ant.GroundPlaneLength = 0.0550

Data Types: double

Width of the ground plane, specified as a positive scalar integer in meters.

Example: 'GroundPlaneWidth',0.0550

Example: ant.GroundPlaneWidth = 0.0550

Data Types: double

Signed distance of fractal snowflake center from origin, specified as a two-element real-valued vector with each element unit in meters. The distance is measured along the length and width of the ground plane.

Example: 'FractalCenterOffset',[0 0.080]

Example: ant.FractalCenterOffset = [0 0.080]

Data Types: double

Signed distance of the feed from the origin, specified as a two-element real-valued vector with each element unit in meters.

Example: 'FeedOffset',[0 0.080]

Example: ant.FeedOffset = [0 0.080]

Data Types: double

Diameter of the feed, measured in meters.

Example: 'FeedDiameter',0.001

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: ant.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.

Note

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: ant.TiltAxis = 'Z'

Note

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

Data Types: double

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. lumpedelement is the object handle for the load created using lumpedElement. For more information, see lumpedElement.

Example: 'Load',lumpedelement.

Example: ant.Load = lumpedElement('Impedance',75,'Frequency',2.9e6,'location',[20e-3 1e-3 1.5e-3])

Object Functions

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

Examples

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Create and View fractal Koch snowflake antenna object with default properties.

ant = fractalSnowflake
ant = 
  fractalSnowflake with properties:

                 Length: 0.0900
          NumIterations: 2
                 Height: 0.0015
              Substrate: [1x1 dielectric]
      GroundPlaneLength: 0.1000
       GroundPlaneWidth: 0.1100
    FractalCenterOffset: [0 0]
             FeedOffset: [0 0]
           FeedDiameter: 0.0020
                   Tilt: 0
               TiltAxis: [1 0 0]
                   Load: [1x1 lumpedElement]

show(ant)

Create and view fractal Koch snowflake on a substrate with a dielectric constant of 4 and thickness of 1.5e-3.

 ant = fractalSnowflake('Substrate', dielectric('EpsilonR',4,...
          'Thickness',1.5e-3));
    show(ant);

Create a fractal Koch snowflake antenna and plot its impedance over a frequency range of 400-1500 MHz.

ant = fractalSnowflake('Length',180e-3,'GroundPlaneLength',280e-3,...
          'GroundPlaneWidth',240e-3,'Height',5e-3,'FeedOffset',...
          [75e-3,-45e-3]);
figure
impedance(ant,(400:10:1500)*1e6)

Introduced in R2020a