# monopole

Create monopole antenna over rectangular ground plane

## Description

The monopole object is a monopole antenna mounted over a rectangular ground plane.

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

$w=2d=4r$

, 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 monopole is center-fed. The feed point coincides with the origin. The origin is located on the xy- plane.

## Creation

### Description

mpl = monopole creates a quarter-wavelength monopole antenna.

example

mpl = monopole(Name,Value) creates a quarter-wavelength 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

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Height of vertical element along z-axis, 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

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

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

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

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

Example: 'FeedOffset',[2 1]

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

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.

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

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.

Example: [0 1 0]

Example: [0 0 0;0 1 0]

Example: "Z"

Data Types: double | string

## Object Functions

 show Display antenna, array structures, shapes, or platform 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 or create AI-based antenna from antenna catalog objects efficiency Radiation efficiency of antenna EHfields Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays impedance Input impedance of antenna or scan impedance of array mesh Mesh properties of metal, dielectric antenna, or array structure meshconfig Change meshing mode of antenna, array, custom antenna, custom array, or custom geometry 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 rcs Calculate and plot radar cross section (RCS) of platform, antenna, or array returnLoss Return loss of antenna or scan return loss of array sparameters Calculate S-parameters for antennas and antenna arrays vswr Voltage standing wave ratio (VSWR) of antenna or array element

## Examples

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Create and view a monopole of 1 m length, 0.01 m width and ground plane of dimensions 2.5mx2.5m.

m = monopole('GroundPlaneLength',2.5,'GroundPlaneWidth',2.5)
m =
monopole with properties:

Height: 1
Width: 0.0100
GroundPlaneLength: 2.5000
GroundPlaneWidth: 2.5000
FeedOffset: [0 0]
Conductor: [1x1 metal]
Tilt: 0
TiltAxis: [1 0 0]

show(m)

Radiation pattern of a monopole at a frequency of 75 MHz.

m = monopole('GroundPlaneLength',2.5, 'GroundPlaneWidth',2.5);
pattern (m,75e6)

## 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