lpda

Create printed log-periodic dipole array antenna

Description

Use the default lpda object to create a printed log-periodic dipole array antenna resonating around 5.14 GHz. 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

Syntax

ant = lpda

ant = lpda(Name=Value)

Description

ant = lpda creates a printed log-periodic dipole array antenna using default property values. The default dimensions are chosen for an operating frequency of around 5.14 GHz.

ant = lpda(Name=Value) sets properties using one or more name-value arguments. Name is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as Name1=Value1,...,NameN=ValueN. Properties that you do not specify, retain their default values.

For example, ant = lpda(BoardLength=0.2) creates a printed log-periodic dipole array with a board length of 0.2 m.

Properties

BoardLength — PCB length along x-axis

0.0366 (default) | scalar

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

Example: 0.2

Data Types: double

BoardWidth — PCB width along y-axis

0.0244 (default) | two-element vector | scalar

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: [0.06 0.06]

Data Types: double

Height — PCB height along z-axis

0.0016 (default) | scalar

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

Example: 0.0018

Data Types: double

StripLineWidth — Parallel strip line width

0.0012 (default) | scalar

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

Example: 0.0014

Data Types: double

FeedLength — Distance from edge feed point to smallest dipole

0.0065 (default) | scalar

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

Example: 0.0055

Data Types: double

ArmLength — Lengths of individual dipole arms

[0.0040 0.0045 0.0050 0.0056 0.0062 0.0069 0.0076 0.0085] (default) | vector

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

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

Data Types: double

ArmWidth — Widths of individual dipole arms

[8.8000e-04 9.8000e-04 0.0011 0.0012 0.0013 0.0015 0.0017 0.0019] (default) | vector

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

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

Data Types: double

ArmSpacing — Spacing between individual dipole arms

[0.0027 0.0030 0.0033 0.0037 0.0041 0.0046 0.0051] (default) | vector

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

Example: [0.0037 0.0040 0.0043 0.0047 0.0051 0.0056 0.0061]

Data Types: double

Substrate — Type of dielectric material

dielectric("FR4") (default) | dielectric object

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

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. 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 for the load created using lumpedElement.

Example: lpda.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

Default Printed Log-Periodic Antenna

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: [8.8000e-04 9.8000e-04 0.0011 0.0012 0.0013 0.0015 0.0017 0.0019]
        ArmSpacing: [0.0027 0.0030 0.0033 0.0037 0.0041 0.0046 0.0051]
         Substrate: [1x1 dielectric]
         Conductor: [1x1 metal]
              Tilt: 0
          TiltAxis: [1 0 0]
              Load: [1x1 lumpedElement]

show(lpdipole)

Create and View Characteristics of Tapered LPDA

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)

Version History

Introduced in R2018a