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dielectric

Dielectric material for use as substrate

Description

example

d = dielectric(material) returns dielectric materials for use as a substrate in antenna elements.

example

d = dielectric(Name=Value) returns dielectric materials, based on the properties specified by one or more Name-Value arguments.

Examples

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Use a Teflon dielectric material as a substrate for a PIFA antenna. View the antenna.

d = dielectric("Teflon")
d = 
  dielectric with properties:

           Name: 'Teflon'
       EpsilonR: 2.1000
    LossTangent: 2.0000e-04
      Thickness: 0.0060

For more materials see catalog

p = pifa(Height=0.0060,Substrate=d)
p = 
  pifa with properties:

               Length: 0.0300
                Width: 0.0200
               Height: 0.0060
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.0360
     GroundPlaneWidth: 0.0360
    PatchCenterOffset: [0 0]
        ShortPinWidth: 0.0200
           FeedOffset: [-0.0020 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(p)

Figure contains an axes object. The axes object with title pifa antenna element, xlabel x (mm), ylabel y (mm) contains 4 objects of type patch, surface. These objects represent PEC, feed, Teflon.

Create a patch microstrip antenna using a substrate with a relative permittivity of 2.70, a loss tangent of 0.002 and a thickness of 0.0008 m. View the antenna.

t = dielectric(Name="Taconic_TLC",EpsilonR=2.70,LossTangent=0.002,...
     Thickness=0.0008);
p = patchMicrostrip(Height=0.0008,Substrate=t)
p = 
  patchMicrostrip with properties:

               Length: 0.0750
                Width: 0.0375
               Height: 8.0000e-04
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.1500
     GroundPlaneWidth: 0.0750
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(p)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 6 objects of type patch, surface. These objects represent PEC, feed, Taconic_TLC.

Create a microstrip patch antenna.

p = patchMicrostrip;

For property values of air and teflon dielectrics, refer Dielectric Catalog.

openDielectricCatalog

Figure Dielectric Materials contains objects of type uimenu, uitoolbar, uitable.

Use Teflon as a dielectric substrate. There is an air gap between the patch groundplane and the dielectric.

sub = dielectric(Name=["Air" "Teflon"],EpsilonR=[1 2.1],...
     Thickness=[0.002 0.004],LossTangent=[0 2e-04]);

Add the substrate to the patch antenna.

p.Substrate = sub;
figure
show(p)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 7 objects of type patch, surface. These objects represent PEC, feed, Teflon.

Create a microstrip patch antenna.

p = patchMicrostrip;

For dielectric properties, use the Dielectric Catalog.

openDielectricCatalog

Figure Dielectric Materials contains objects of type uimenu, uitoolbar, uitable.

Use FR4, Teflon and Foam as the three layers of the substrate.

sub = dielectric(Name=["FR4" "Teflon" "Foam"],EpsilonR=...
    [4.80 2.10 1.03],Thickness=[0.002 0.004 0.001],...
    LossTangent=[0.0260 2e-04 1.5e-04]);

Add the three layer substrate to the patch antenna.

p.Substrate = sub;
figure
show(p)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 8 objects of type patch, surface. These objects represent PEC, feed, FR4, Teflon, Foam.

Plot the radiation pattern of the antenna.

figure
pattern(p,1.67e9)

Figure contains an axes object and other objects of type uicontrol. The axes object contains 8 objects of type patch, surface. These objects represent FR4, Teflon, Foam.

Design a dipole antenna backed by a dielectric substrate and an infinite reflector.

Create a dipole antenna of length, 0.15 m, and width, 0.015 m.

d = dipole(Length=0.15,Width=0.015,Tilt=90,TiltAxis=[0 1 0]);

Create a reflector using the dipole antenna as an exciter and the dielectric, teflon as the substrate.

t = dielectric("Teflon")
t = 
  dielectric with properties:

           Name: 'Teflon'
       EpsilonR: 2.1000
    LossTangent: 2.0000e-04
      Thickness: 0.0060

For more materials see catalog

rf = reflector(Exciter=d,Spacing=7.5e-3,Substrate=t);

Set the groundplane length of the reflector to inf. View the structure.

rf.GroundPlaneLength = inf;
show(rf)

Figure contains an axes object. The axes object with title dipole over infinite ground plane, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed, Teflon, infinite ground.

Calculate the radiation pattern of the antenna at 70 MHz.

pattern(rf,70e6)

Figure contains an axes object and other objects of type uicontrol. The axes object contains 5 objects of type patch, surface. These objects represent Teflon, infinite ground.

Compare the gain values of a dipole antenna in free space and dipole antenna on a substrate.

Design a dipole antenna at a frequency of 1 GHz.

d = design(dipole,1e9);
l_by_w = d.Length/d.Width;
d.Tilt = 90;
d.TiltAxis = [0 1 0];

Plot the radiation pattern of the dipole in free space at 1 GHz.

figure
pattern(d,1e9);

Figure contains an axes object and other objects of type uicontrol. The axes object contains 3 objects of type patch, surface.

Use FR4 as the dielectric substrate.

t = dielectric("FR4")
t = 
  dielectric with properties:

           Name: 'FR4'
       EpsilonR: 4.8000
    LossTangent: 0.0260
      Thickness: 0.0060

For more materials see catalog

eps_r = t.EpsilonR;
lambda_0 = physconst("lightspeed")/1e9;
lambda_d = lambda_0/sqrt(eps_r);

Adjust the length of the dipole based on the wavelength.

d.Length = lambda_d/2;
d.Width = d.Length/l_by_w;

Design a reflector at 1 GHz with the dipole as the exciter and FR4 as the substrate.

rf = reflector(Exciter=d,Spacing=7.5e-3,Substrate=t);
rf.GroundPlaneLength = lambda_d;
rf.GroundPlaneWidth = lambda_d/4;
figure
show(rf)

Figure contains an axes object. The axes object with title reflector antenna element, xlabel x (mm), ylabel y (mm) contains 6 objects of type patch, surface. These objects represent PEC, feed, FR4.

Remove the groundplane for plotting the gain of the dipole on the substrate.

rf.GroundPlaneLength = 0;
show(rf)

Figure contains an axes object. The axes object with title reflector antenna element, xlabel x (mm), ylabel y (mm) contains 4 objects of type patch, surface. These objects represent PEC, feed, FR4.

Plot the radiation pattern of the dipole on the substrate at 1 GHz.

figure
pattern(rf,1e9);

Figure contains an axes object and other objects of type uicontrol. The axes object contains 4 objects of type patch, surface. This object represents FR4.

Compare the gain values.

  • Gain of the dipole in free space = 2.11 dBi

  • Gain of the dipole on substrate = 1.93 dBi

Input Arguments

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Material from the dielectric catalog, specified as one or more dielectrics from the DielectricCatalog object with predefined properties. You can specify multiple dielectric layers and create an array of dielectrics.

Example: "FR4"

Example: "FR4","Teflon"

Example: [dielectric("FR4") dielectric("Teflon")]

Data Types: string

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: Name="Air"

Name of the dielectric material you want to specify in the output, specified as a string.

Example: "Taconic_TLC"

Data Types: string

Relative permittivity of the dielectric material, specified as a positive scalar or vector.

Example: 4.8000

Data Types: double

Loss in the dielectric material, specified as a scalar or vector.

Note

In Antenna Toolbox™, the upper limit to loss tangent value is 0.03.

Example: 0.0260

Data Types: double

Thickness of the dielectric material along default z-axis, specified as a scalar or vector in meters. This property applies only when you call the function with no output arguments.

Example: 0.05

Data Types: double

Output Arguments

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Dielectric material, returned as an object. You can use the dielectric material object to add dielectric material to an antenna.

Version History

Introduced in R2016a