linearArray

Create linear antenna array

Description

The linearArray object creates a linear antenna array in the xy-plane. The default linear array is a two-element dipole array. The dipoles are center-fed. Each dipole resonates at 70 MHz when isolated.

Creation

Syntax

array = linearArray

array = linearArray(Name=Value)

Description

array = linearArray creates a linear antenna array in the xy-plane.

array = linearArray(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, linArr = linearArray(Element=discone) creates a linear array of two discone antennas.

Output Arguments

array — Linear array

linearArray object

Linear array, returned as an linearArray object.

Properties

Element — Individual antenna type in array

dipole (default) | antenna object | linearArray object | customAntennaMesh object | customAntennaGeometry object | customAntennaStl object | customAntenna object | vector of antenna objects

Individual antenna type, specified as a single antenna object for homogeneous array or a vector of antenna objects of same type with varying dimensions and load for heterogeneous array. The antenna object can be an element from the Antenna Catalog, or a linearArray, or an antenna without a substrate created using customAntennaGeometry, customAntennaMesh, customAntennaStl, or customAntenna objects.

Note

Following antennas are not supported as an element:

• cavity, cavityCircular

• slot, vivaldiAntipodal

• Antennas with tilted ground planes.

• All reflector antennas except reflector with a dipole exciter.

Example: monopole

Example: [monopole monopole(Height=2)]

Example: linearArray

Example: customAntenna

NumElements — Number of antenna or linear array elements in array

2 (default) | scalar

Number of antenna or linear array elements in array, specified as a scalar.

Example: 4

ElementSpacing — Spacing between antenna elements or arrays in array

2 (default) | scalar | vector

Spacing between antenna elements or arrays in array, specified as a scalar or vector in meters. By default, the dipole elements are spaced 2m apart.

Example: 3

Data Types: double

AmplitudeTaper — Excitation amplitude of antenna elements

1 (default) | scalar | vector

Excitation amplitude of antenna elements, specified as a scalar or vector. Set the property value to 0 to model dead elements. This value corresponds to the excitation voltages for the elements in the array.

Example: 3

Data Types: double

Phaseshift — Phase shift for antenna elements

0 (default) | scalar | vector

Phase shift for antenna elements, specified as a scalar or vector in degrees. This value corresponds to the excitation voltages for the elements in the array.

Example: [3 3 0 0]

Data Types: double

Tilt — Tilt angle of array

0 (default) | numeric scalar | numeric vector

Tilt angle of the array 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 array at 90 degrees about the two axes, defined by the vectors.

Data Types: double

TiltAxis — Tilt axis of array

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

Tilt axis of the array, specified as one of these values:

• Three-element vectors 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, specified as a 2-by-3 matrix corresponding to two three-element vectors of Cartesian coordinates. In this case, the array 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

arrayFactor	Array factor in dB
axialRatio	Calculate and plot axial ratio of antenna or array
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
correlation	Correlation coefficient between two antennas in array
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
layout	Display array or PCB stack layout
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
patternMultiply	Radiation pattern of array using pattern multiplication
peakRadiation	Calculate and mark maximum radiation points of antenna or array on radiation pattern
phaseShift	Calculate phase shift values for arrays or multi-feed PCB stack
rcs	Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
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 Plot Layout of Linear Array

Create a linear array of four dipoles and plot the layout of the array.

la = linearArray;
la.NumElements = 4;
layout(la);

Radiation Pattern of Linear Array

Plot the radiation pattern of a four element linear array of dipoles at a frequency 70MHz.

la = linearArray(NumElements=4);
pattern(la,70e6);

Linear Array Using Groundplane Antennas

Create a linear array of two monopoles.

m1 = monopole;
m2 = monopole(Height=0.5);
mla = linearArray

mla = 
  linearArray with properties:

           Element: [1x1 dipole]
       NumElements: 2
    ElementSpacing: 2
    AmplitudeTaper: 1
        PhaseShift: 0
              Tilt: 0
          TiltAxis: [1 0 0]

mla.Element = [m1 m2];
show(mla);

Rectangular Array of Linear Array

Create an array of discones with 3 m. element spacing.

la = linearArray(Element=discone);
la.ElementSpacing = 3;
show(la)

Create a rectangular array of the linear array.

ra = rectangularArray(Element=la)

ra = 
  rectangularArray with properties:

           Element: [1x1 linearArray]
              Size: [2 2]
        RowSpacing: 2
     ColumnSpacing: 2
           Lattice: 'Rectangular'
    AmplitudeTaper: 1
        PhaseShift: 0
              Tilt: 0
          TiltAxis: [1 0 0]

show(ra)

Pattern of Linear Array of Linear Array

Create a linear array of a linear array with 1 m. element spacing and plot the directivity pattern at 70 MHz.

la = linearArray(Element=linearArray(ElementSpacing=1)); 
show(la)

pattern(la,70e6); 

References

[1] Balanis, C.A. Antenna Theory. Analysis and Design, 3rd Ed. New York: Wiley, 2005.

Version History

Introduced in R2015a