lpda

Create printed log-periodic dipole array antenna

Description

Use the lpda object to create a printed log-periodic dipole array antenna. The default antenna is centered at the origin and uses an FR4 substrate. This antenna is widely used in communication and radar due to advantages such as wideband, high gain, and high directivity.

Creation

Description

example

lpdipole = lpda creates a printed log-periodic dipole array antenna using default property values.

example

lpdipole = lpda(Name,Value) sets properties using one or more name-value pairs. For example, lpdipole = lpda('BoardLength',0.2) creates a printed log-periodic dipole array with a board length of 0.2 m.

Note

Properties which are not specified retain their default values.

Properties

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Printed circuit board (PCB) length along X-axis, specified as a scalar in meters.

Example: 'BoardLength',0.2

Example: lpdipole.BoardLength = 0.2

Data Types: double

PCB width along Y-axis, specified in meters . Width of the PCB in meter. If the value is a scalar, a rectangular board is created and if the value is a vector with 2 elements, a trapezoidal board is created. The first element represents width of the board at the shortest end of the dipole and the second element represents width at the longest end of the dipole.

Example: 'BoardWidth',[0.06 0.06]

Example: lpdipole.BoardWidth = [10e-3 12e-3]

Data Types: double

PCB height along Z-axis, specified as a scalar in meters.

Example: 'Height',0.0018

Example: lpdipole.Height = 0.0018

Data Types: double

Width of the parallel strip, specified as a scalar in meters.

Example: 'StripLineWidth',0.0014

Example: lpdipole.StripLineWidth = 0.0014

Data Types: double

The distance from the feed point to the smallest dipole , specified as a scalar in meters.

Example: 'FeedLength',0.0055

Example: lpdipole.FeedLength = 0.0055

Data Types: double

Lengths of individual dipole arms, specified as a vector with each element unit in meters.

Example: 'ArmLength',[0.0050 0.0055 0.0060 0.0066 0.0072 0.0079 0.0086 0.0095]

Example: lpdipole.ArmLength = [0.0050 0.0055 0.0060 0.0066 0.0072 0.0079 0.0086 0.0095]

Data Types: double

Widths of individual dipole arms, specified as a vector with each element unit in meters.

Example: 'ArmWidth',[9.8000e-04 10.8000e-04 0.0021 0.0022 0.0023 0.0025 0.0027 0.0029]

Example: lpdipole.ArmWidth = [9.8000e-04 10.8000e-04 0.0021 0.0022 0.0023 0.0025 0.0027 0.0029]

Data Types: double

Spacing between individual dipole arms, specified as a vector with each element unit in meters.

Example: 'ArmSpacing',[0.0037 0.0040 0.0043 0.0047 0.0051 0.0056 0.0061]

Example: lpdipole.ArmSpacing = [0.0037 0.0040 0.0043 0.0047 0.0051 0.0056 0.0061]

Data Types: double

Type of dielectric material used as a substrate, specified as an dielectric object. For more information, see dielectric. For more information on dielectric substrate meshing, see Meshing.

Note

The substrate dimensions must be equal to the groundplane dimensions.

Example: d = dielectric('Teflon'); 'Substrate',d

Example: d = dielectric('Teflon'); lpdipole.Substrate = d

Lumped elements added to the antenna feed, specified as a lumped element 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, where lumpedelement is the object handle for the load created using lumpedElement.

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

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.

Note

The wireStack antenna object only accepts the dot method to change its properties.

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'

Note

The wireStack antenna object only accepts the dot method to change its properties.

Data Types: double

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
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
optimizeOptimize antenna or array using SADEA optimizer
patternRadiation pattern and phase 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 a printed log-periodic dipole array antenna.

lpdipole = lpda
lpdipole = 
  lpda with properties:

       BoardLength: 0.0366
        BoardWidth: 0.0244
            Height: 0.0016
    StripLineWidth: 0.0012
        FeedLength: 0.0065
         ArmLength: [0.0040 0.0045 0.0050 0.0056 0.0062 0.0069 0.0076 0.0085]
          ArmWidth: [1x8 double]
        ArmSpacing: [0.0027 0.0030 0.0033 0.0037 0.0041 0.0046 0.0051]
         Substrate: [1x1 dielectric]
              Tilt: 0
          TiltAxis: [1 0 0]
              Load: [1x1 lumpedElement]

show(lpdipole)

Create a tapered LPDA object and plot impedance over a frequency of 5 - 8GHz. This example also shows how to plot the 3-D radiation pattern of the antenna.

lpdipole = lpda('BoardWidth',[20.37e-3 24.37e-3]);
show(lpdipole)

Plot Impedance over the specified frequency range.

freq = linspace(5e9, 8e9, 41);
figure;
impedance(lpdipole,freq)

Plot the 3-D radiation pattern at 5.8 GHz.

pattern(lpdipole,5.8e9)

Introduced in R2018a