monopoleTopHat

Create capacitively loaded monopole antenna over rectangular ground plane

Description

The monopoleTopHat object is a top-hat monopole antenna mounted over a rectangular ground plane. The monopole always connects with the center of top hat. The top hat builds up additional capacitance to ground within the structure. This capacitance reduces the resonant frequency of the antenna without increasing the size of the element.

The width of the monopole is related to the diameter of an equivalent cylindrical monopole by the expression

$w = 2 d = 4 r$

where:

d is the diameter of equivalent cylindrical monopole
r is the radius of equivalent cylindrical monopole.

For a given cylinder radius, use the cylinder2strip utility function to calculate the equivalent width. The default top-hat monopole is center-fed. The feed point coincides with the origin. The origin is located on the xy- plane.

Creation

Syntax

mth = monopoleTopHat

mth = monopoleTopHat(Name,Value)

Description

example

mth = monopoleTopHat creates a capacitively loaded monopole antenna over a rectangular ground plane.

mth = monopoleTopHat(Name,Value) creates a capacitively loaded monopole antenna with additional properties specified by one or more name-value pair arguments. Name is the property name and Value is the corresponding value. You can specify several name-value pair arguments in any order as Name1, Value1,..., NameN, ValueN. Properties not specified retain their default values.

Properties

expand all

`Height` — Monopole height
1 (default) | scalar

Monopole height, specified as a scalar in meters. By default, the height is chosen for an operating frequency of 75 MHz.

Example: 'Height',3

Data Types: double

`Width` — Monopole width
0.1000 (default) | scalar

Monopole width, specified as a scalar in meters.

Note

Monopole width should be less than 'Height'/4 and greater than 'Height'/1001. [2]

Example: 'Width',0.05

Data Types: double

`GroundPlaneLength` — Ground plane length along x-axis
2 (default) | scalar

Ground plane length along x-axis, specified as a scalar in meters. Setting 'GroundPlaneLength' to Inf, uses the infinite ground plane technique for antenna analysis.

Example: 'GroundPlaneLength',4

Data Types: double

`GroundPlaneWidth` — Ground plane width along y-axis
2 (default) | scalar

Ground plane width along y-axis, specified as a scalar in meters. Setting 'GroundPlaneWidth' to Inf, uses the infinite ground plane technique for antenna analysis.

Example: 'GroundPlaneWidth',2.5

Data Types: double

`TopHatLength` — Top hat length along x-axis
0.2500 (default) | scalar

Top hat length along x-axis, specified as a scalar in meters.

Example: 'TopHatLength',4

Data Types: double

`TopHatWidth` — Top hat width along y-axis
0.2500 (default) | scalar

Top hat width along y-axis, specified as a scalar in meters.

Example: 'TopHatWidth',4

Data Types: double

`FeedOffset` — Signed distance from center along length and width of ground plane
`[0 0]` (default) | two-element vector

Signed distance from center along length and width of ground plane, specified as a two-element vector.

Example: 'FeedOffset',[2 1]

Data Types: double

`Substrate` — Type of dielectric material
`'Air'` (default) | `dielectric` object

Type of dielectric material used as the substrate, specified as a dielectric object. You can also specify multiple dielectric layers. When creating multiple dielectric layers, in the dielectric function, specify the name, thickness, loss tangent, and relative permittivity of each layer. For more information, see dielectric. For more information on dielectric substrate meshing, see Meshing.

Example: d = dielectric('FR4'); mth = monopoleTopHat('Substrate',d)

Example: d = dielectric('FR4'); mth = MonopoleTopHat; mth.Substrate = d

Example: d = dielectric('Name',{'FR4','Teflon'},'Thickness',[0.5 0.5],'LossTangent',[0.002 0.002],'EpsilonR',[4.8 2.1]); mth = monopoleTopHat('Substrate',d)

`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 information, see metal. For more information on metal conductor meshing, see Meshing.

Example: m = metal('Copper'); 'Conductor',m

Example: m = metal('Copper'); ant.Conductor = m

`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 lumpedElement.

Example: 'Load',lumpedelement. lumpedelement is the object for the load created using lumpedElement.

Example: mth.Load = lumpedElement('Impedance',75)

`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.

Example: 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

`TiltAxis` — Tilt axis of antenna
`[1 0 0]` (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates | `'X'` | `'Y'` | `'Z'`

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: TiltAxis = 'Z'

Data Types: double

Object Functions

`show`	Display antenna, array structures or shapes
`info`	Display information about antenna or array
`axialRatio`	Axial ratio of antenna
`beamwidth`	Beamwidth of antenna
`charge`	Charge distribution on antenna or array surface
`current`	Current distribution on antenna or array surface
`design`	Design prototype antenna or arrays for resonance around specified frequency
`efficiency`	Radiation efficiency of antenna
`EHfields`	Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
`impedance`	Input impedance of antenna; scan impedance of array
`mesh`	Mesh properties of metal, dielectric antenna, or array structure
`meshconfig`	Change mesh mode of antenna structure
`optimize`	Optimize antenna or array using SADEA optimizer
`pattern`	Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
`patternAzimuth`	Azimuth pattern of antenna or array
`patternElevation`	Elevation pattern of antenna or array
`rcs`	Calculate and plot radar cross section (RCS) of platform, antenna, or array
`returnLoss`	Return loss of antenna; scan return loss of array
`sparameters`	Calculate S-parameter for antenna and antenna array objects
`vswr`	Voltage standing wave ratio of antenna

Examples

collapse all

Create and View Top-Hat Monopole

Open Live Script

Create and view a top-hat monopole with 1 m length, 0.01 m width, groundplane dimensions 2mx2m and top hat dimensions 0.25mx0.25m.

th = monopoleTopHat

th = 
  monopoleTopHat with properties:

               Height: 1
                Width: 0.0100
    GroundPlaneLength: 2
     GroundPlaneWidth: 2
         TopHatLength: 0.2500
          TopHatWidth: 0.2500
            Substrate: [1x1 dielectric]
           FeedOffset: [0 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(th)

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

Calculate Impedance of Top-Hat Monopole Antenna

Open Live Script

Calculate and plot the impedance of a top-hat monopole over a frequency range of 40 MHz-80 MHz.

th = monopoleTopHat;
impedance(th,linspace(40e6,80e6,41));

Figure contains an axes object. The axes object with title Impedance, xlabel Frequency (MHz), ylabel Impedance (ohms) contains 2 objects of type line. These objects represent Resistance, Reactance.

Compare Impedance of Top-Hat Monopole Antenna and Monopole Antenna

Open Live Script

Impedance comparison between a monopole of similar dimensions and the top-hat monopole in example 2.

m = monopole;
figure
impedance(m,linspace(40e6,80e6,41));

Figure contains an axes object. The axes object with title Impedance, xlabel Frequency (MHz), ylabel Impedance (ohms) contains 2 objects of type line. These objects represent Resistance, Reactance.

Top-Hat Monopole with Multiple Dielectric Layers

Open Live Script

Create a top-hat monopole with default dimensions and a substrate with two dielectric layers.

mth = monopoleTopHat;
d = dielectric('Name',{'FR4','Teflon'},'Thickness',[0.5 0.5],'LossTangent',[0.002 0.002],'EpsilonR',[4.8 2.1]);
mth.Substrate = d

mth = 
  monopoleTopHat with properties:

               Height: 1
                Width: 0.0100
    GroundPlaneLength: 2
     GroundPlaneWidth: 2
         TopHatLength: 0.2500
          TopHatWidth: 0.2500
            Substrate: [1x1 dielectric]
           FeedOffset: [0 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

View the top-hat monopole antenna.

show(mth)

Figure contains an axes object. The axes object with title monopoleTopHat antenna element, xlabel x (m), ylabel y (m) contains 7 objects of type patch, surface. These objects represent PEC, feed, FR4, Teflon.

References

[1] Balanis, C.A. Antenna Theory. Analysis and Design, 3rd Ed. New York: Wiley, 2005.

[2] Volakis, John. Antenna Engineering Handbook, 4th Ed. New York: Mcgraw-Hill, 2007.

Version History

Introduced in R2015a

monopoleTopHat

Description

Creation

Syntax

Description

Properties

`Height` — Monopole height
1 (default) | scalar

`Width` — Monopole width
0.1000 (default) | scalar

`GroundPlaneLength` — Ground plane length along x-axis
2 (default) | scalar

`GroundPlaneWidth` — Ground plane width along y-axis
2 (default) | scalar

`TopHatLength` — Top hat length along x-axis
0.2500 (default) | scalar

`TopHatWidth` — Top hat width along y-axis
0.2500 (default) | scalar

`FeedOffset` — Signed distance from center along length and width of ground plane
`[0 0]` (default) | two-element vector

`Substrate` — Type of dielectric material
`'Air'` (default) | `dielectric` object

`Conductor` — Type of metal material
`'PEC'` (default) | `metal` object

`Load` — Lumped elements
[1x1 lumpedElement] (default) | lumped element object

`Tilt` — Tilt angle of antenna
`0` (default) | scalar | vector

`TiltAxis` — Tilt axis of antenna
`[1 0 0]` (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates | `'X'` | `'Y'` | `'Z'`

Object Functions

Examples

Create and View Top-Hat Monopole

Calculate Impedance of Top-Hat Monopole Antenna

Compare Impedance of Top-Hat Monopole Antenna and Monopole Antenna

Top-Hat Monopole with Multiple Dielectric Layers

References

Version History

See Also

Topics

monopoleTopHat

Description

Creation

Syntax

Description

Properties

Height — Monopole height 1 (default) | scalar

Width — Monopole width 0.1000 (default) | scalar

GroundPlaneLength — Ground plane length along x-axis 2 (default) | scalar

GroundPlaneWidth — Ground plane width along y-axis 2 (default) | scalar

TopHatLength — Top hat length along x-axis 0.2500 (default) | scalar

TopHatWidth — Top hat width along y-axis 0.2500 (default) | scalar

FeedOffset — Signed distance from center along length and width of ground plane [0 0] (default) | two-element vector

Substrate — Type of dielectric material 'Air' (default) | dielectric object

Conductor — Type of metal material 'PEC' (default) | metal object

Load — Lumped elements [1x1 lumpedElement] (default) | lumped element object

Tilt — Tilt angle of antenna 0 (default) | scalar | vector

TiltAxis — Tilt axis of antenna [1 0 0] (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates | 'X' | 'Y' | 'Z'

Object Functions

Examples

Create and View Top-Hat Monopole

Calculate Impedance of Top-Hat Monopole Antenna

Compare Impedance of Top-Hat Monopole Antenna and Monopole Antenna

Top-Hat Monopole with Multiple Dielectric Layers

References

Version History

See Also

Topics

WeChat

`Height` — Monopole height
1 (default) | scalar

`Width` — Monopole width
0.1000 (default) | scalar

`GroundPlaneLength` — Ground plane length along x-axis
2 (default) | scalar

`GroundPlaneWidth` — Ground plane width along y-axis
2 (default) | scalar

`TopHatLength` — Top hat length along x-axis
0.2500 (default) | scalar

`TopHatWidth` — Top hat width along y-axis
0.2500 (default) | scalar

`FeedOffset` — Signed distance from center along length and width of ground plane
`[0 0]` (default) | two-element vector

`Substrate` — Type of dielectric material
`'Air'` (default) | `dielectric` object

`Conductor` — Type of metal material
`'PEC'` (default) | `metal` object

`Load` — Lumped elements
[1x1 lumpedElement] (default) | lumped element object

`Tilt` — Tilt angle of antenna
`0` (default) | scalar | vector

`TiltAxis` — Tilt axis of antenna
`[1 0 0]` (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates | `'X'` | `'Y'` | `'Z'`