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monopoleCustom

Create customized monopole antenna

Description

The monopoleCustom object creates a monopole radiator of any shape using the antenna.Shape class. 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.

Custom monopole antenna geometry, default radiation pattern, and impedance plot.

Creation

Description

example

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 X-Y plane. The default antenna resonates at an operating frequency of 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

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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.

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.

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

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

Data Types: double

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 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

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'

Lumped elements added to the antenna feed, specified as a lumpedElement object handle. 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 handle for the load created using lumpedElement.

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

Object Functions

showDisplay antenna or array structure; display shape as filled patch
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on metal or dielectric antenna or array surface
currentCurrent distribution on metal or dielectric antenna or array surface
efficiencyRadiation efficiency of antenna
EHfieldsElectric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedanceInput impedance of antenna; scan impedance of array
meshMesh properties of metal or dielectric antenna or array structure
optimizeOptimize antenna or array using SADEA optimizer
patternPlot antenna radiation pattern on map
patternAzimuthAzimuth pattern of antenna or array
patternElevationElevation pattern of antenna or array
rcsCalculate and plot radar cross section (RCS) of platform, antenna, or array
returnLossReturn loss of antenna; scan return loss of array
sparametersS-parameter object
vswrVoltage standing wave ratio of antenna

Examples

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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);  

Figure contains an axes. The axes with title monopoleCustom antenna element contains 4 objects of type patch, surface. These objects represent PEC, feed.

Plot the radiation pattern of the antenna at 2.05 GHz.

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

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

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.

Introduced in R2020b