monopoleCustom

Create customized monopole antenna

Since R2020b

Description

The default monopoleCustom object creates a monopole radiator of any shape using the antenna.Shape class resonating around 1.24 GHz. The ground plane can take any shape. You can create any arbitrarily shaped monopole and analyze it for field, surface, and port characteristics. Monopole antennas have a simple structure and provide omnidirectional radiation patterns with wide impedance bandwidth. Monopole antennas are commonly used in airborne and ground-based communication systems.

Creation

Syntax

ant = monopoleCustom

ant = monopoleCustom(Name,Value)

Description

ant = monopoleCustom creates a default monopole antenna with a square radiator and a circular ground plane. The feed point is at the origin in the xy- plane. The default dimensions are chosen for an operating frequency of around 1.24 GHz.

ant = monopoleCustom(Name,Value) sets Properties using one or more name-value pairs. For example, ant = monopoleCustom('RadiatorTilt',90) creates a monopole antenna with tilt angle of the radiator at 90 degrees on the z-axis.

Properties

Radiator — Type of radiator

antenna.Rectangle object (default) | antenna.Polygon object

Type of radiator, specified as an antenna.Polygon object. You can specify any shape for the radiator. The feed strip is a part of the radiator. By default, the radiator is square in shape with a side length of 40e-3 meters. The feed strip is 2e-3 meters in length and 2.5e-3 meters in width at the edge of the radiator.

GroundPlane — Type of ground plane

antenna.Circle (default) | antenna.Polygon object

Type of ground plane, specified as an antenna.Polygon object. You can specify any shape for the ground plane. By default, the ground plane is circular in shape with a radius of 150e-3 meters.

FeedOffset — Signed distance from center along length and width of ground plane

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

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

Example: 'FeedOffset',[2 1]

Data Types: double

RadiatorTilt — Tilt angle of radiator

0 (default) | scalar

Tilt angle of the radiator, specified as a scalar in degrees.

Data Types: double

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

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: 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.

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: ant.TiltAxis = 'Z'

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. For more information, see lumpedElement.

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

Example: ant.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
charge	Charge distribution on antenna or array surface
current	Current distribution on antenna or array surface
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	Display antenna radiation pattern in Site Viewer
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

Create Disc Monopole Antenna on Square Ground Plane

Create a disc monopole with a of radius 25 mm, on a square ground plane of 30 cm, and with a feed gap of 0.7 mm.

Rad = antenna.Circle(Radius=25e-3);
FeedStrip = antenna.Rectangle(Length=1e-3,Width=0.7e-3,...
    Center=[0 -(Rad.Radius+(0.7e-3)*0.3)]);
m = monopoleCustom;
m.Radiator = Rad + FeedStrip;
m.GroundPlane = antenna.Rectangle(Length=300e-3,Width=300e-3);

View the antenna using the show function.

show(m)

Plot the radiation pattern of the antenna at 2.05 GHz.

p = PatternPlotOptions(MagnitudeScale=[-40 5]);
pattern(m,2.05e9,PatternOptions=p);

References

[1] Ammann, M. J. “Square Planar Monopole Antenna.” IEE National Conference on Antennas and Propagation, vol. 1999, IEE, pp. 37–40.

[2] Weiner, M. “Monopole Element at the Center of a Circular Ground Plane Whose Radius Is Small or Comparable to a Wavelength.” IEEE Transactions on Antennas and Propagation, vol. 35, no. 5, pp. 488–495.

[3] N. P. Agrawall, G. Kumar and K. P. Ray, "Wide-band planar monopole antennas," in IEEE Transactions on Antennas and Propagation, vol. 46, no. 2, pp. 294-295.

Version History

Introduced in R2020b