monopole

Create monopole antenna over rectangular ground plane

Description

The default monopole object is a monopole antenna mounted over a rectangular ground plane resonating around 72 MHz.

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

Syntax

mpl = monopole

mpl = monopole(Name,Value)

Description

mpl = monopole creates a quarter-wavelength monopole antenna with default dimensions. The default dimensions are chosen for an operating frequency of around 72 MHz.

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

Height — Height of vertical element along z-axis

1 (default) | scalar

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

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

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

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: mpl.Load = lumpedElement('Impedance',75)

Tilt — Tilt angle of antenna

0 (default) | scalar | vector

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

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector | 2-by-3 matrix | "X" | "Y" | "Z"

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.

For more information, see Rotate Antennas and Arrays.

Example: [0 1 0]

Example: [0 0 0;0 1 0]

Example: "Z"

Data Types: double | string

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
design	Design prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
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	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
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 and View Monopole Antenna

Create and view a monopole of 1m length, 0.01m width and a 2.5m-by-2.5m ground plane.

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]
                 Load: [1x1 lumpedElement]

show(m)

Radiation Pattern of Monopole Antenna

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