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invertedF

Create inverted-F antenna over rectangular ground plane

Description

The invertedF object is an inverted-F antenna mounted over a rectangular ground plane.

The width of the metal strip is related to the diameter of an equivalent cylinder by the equation

w=2d=4r

where:

  • d is the diameter of equivalent cylinder

  • r is the radius of equivalent cylinder

For a given cylinder radius, use the utility function cylinder2strip to calculate the equivalent width. The default inverted-F antenna is center-fed. The feed point coincides with the origin. The origin is located on the X-Y plane.

Creation

Syntax

f = invertedF
f = invertedF(Name,Value)

Description

f = invertedF creates an inverted-F antenna mounted over a rectangular ground plane. By default, the dimensions are chosen for an operating frequency of 1.7 GHz.

example

f = invertedF(Name,Value) creates an inverted-F 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

Vertical element height along z-axis, specified a scalar in meters.

Example: 'Height',3

Data Types: double

Strip width, specified as a scalar in meters.

Note

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

Example: 'Width',0.05

Data Types: double

Stub length from feed to open end, specified as a scalar in meters.

Example: 'LengthToOpenEnd',0.05

Stub length from feed to shorting end, specified as a scalar in meters.

Example: 'LengthToShortEnd',0.0050

Ground plane length along x-axis, specified as a scalar in meters. Setting 'GroundPlaneLength' to Inf, will use 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, will use 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

Lumped elements added to the antenna feed, specified as a lumped element object handle. For more information, see lumpedElement.

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

Tilt angle of antenna, specified as a scalar or vector with each element unit in degrees.

Example: 'Tilt',90

Example: 'Tilt',[90 90 0]

Data Types: double

Tilt axis of the antenna, specified as:

  • A three-element vector of Cartesian coordinates in meters. In this case, each vector starts at the origin and lies along the specified points on the X, Y, and Z axes.

  • Two points in space as three-element vectors of Cartesian coordinates. In this case, the antenna rotates along the line joining the two points.

  • A string input for simple rotations around the principal planes, X, Y, or Z.

For more information see, Rotate Antenna and Arrays

Example: 'TiltAxis',[0 1 0]

Example: 'TiltAxis',[0 0 0;0 1 0]

Example: 'TiltAxis','Z'

Data Types: double

Object Functions

showDisplay antenna or array structure; Display shape as filled patch
infoDisplay information about antenna or array
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
designDesign prototype antenna for resonance at specified frequency
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
meshconfigChange mesh mode of antenna structure
patternRadiation pattern of antenna or array; Embedded pattern of antenna element in array
patternAzimuthAzimuth pattern of antenna or array
patternElevationElevation pattern of 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 and view an inverted-F antenna with 14mm height over a ground plane of dimensions 200mmx200mm.

f = invertedF('Height',14e-3, 'GroundPlaneLength',200e-3,          ...
                  'GroundPlaneWidth',200e-3);
show(f)

This example shows you how to plot the radiation pattern of an inverted-F antenna for a frequency of 1.3GHz.

f = invertedF('Height',14e-3, 'GroundPlaneLength', 200e-3,          ...
                  'GroundPlaneWidth', 200e-3);
pattern(f,1.39e9)

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.

Introduced in R2015a

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