fractalSnowflake

Create fractal Koch snowflake antenna

Since R2020a

Description

The default fractalSnowflake object creates a Koch snowflake fractal antenna resonating around 4.12 GHz. 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

Syntax

ant = fractalSnowflake

ant = fractalSnowflake(Name=Value)

Description

ant = fractalSnowflake creates a Koch’s snowflake fractal antenna with default property values. The default fractal is centered at the origin, and the number of iterations is set to 2. The default dimensions are chosen for an operating frequency of around 4.12 GHz.

ant = fractalSnowflake(Name=Value) setsproperties using 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 that you do not specify, retain their default values.

For example, ant = fractalSnowflake(Numiterations=4) creates a Koch's snowflake with four iterations.

Properties

NumIterations — Number of iterations performed on fractal antenna

2 (default) | scalar integer

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

Example: 4

Data Types: double

Length — Length of the sides of the equilateral triangle

0.0900 (default) | positive scalar integer

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

Example: 0.5000

Data Types: double

Height — Height of fractal

0.0015 (default) | positive scalar integer

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

Example: 0.0050

Data Types: double

Substrate — Type of dielectric material

dielectric("Air") (default) | dielectric object

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")

Example: dielectric(Name="RO4003C",EpsilonR=3.38,LossTangent=0.0027,Thickness=0.508e-3)

GroundPlaneLength — Length of ground plane

0.1000 (default) | positive scalar integer

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

Example: 0.0550

Data Types: double

GroundPlaneWidth — Width of ground plane

0.1100 (default) | positive scalar integer

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

Example: 0.0550

Data Types: double

FractalCenterOffset — Signed distance of fractal snowflake center from origin

[0 0] (default) | two-element real-valued vector

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: [0 0.080]

Data Types: double

FeedOffset — Signed distance of feed from origin

[0 0] (default) | two-element real-valued vector

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

Example: [0 0.080]

Data Types: double

FeedDiameter — Diameter of feed

0.0020 ] (default) | positive scalar integer

Diameter of the feed, measured in meters.

Example: 0.001

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")

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

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: Load=lumpedElement(Impedance=75)

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

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
current	Current distribution on antenna or array surface
charge	Charge distribution on antenna or array surface
design	Design prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
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	Mesh properties of metal, dielectric antenna, or array structure
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 or array using SADEA optimizer
pattern	Plot radiation pattern and phase of antenna or array or embedded pattern of antenna element in 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
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

Fractal Snowflake with Default Properties

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
              Conductor: [1x1 metal]
                   Tilt: 0
               TiltAxis: [1 0 0]
                   Load: [1x1 lumpedElement]

show(ant)

Fractal Snowflake Antenna with Specified Parameters

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)

Impedance Plot of Fractal Koch Snowflake Antenna

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)

Version History

Introduced in R2020a