infiniteArray

Create infinite array of 2-D custom antenna in X-Y plane

Description

The infiniteArray object is an infinite antenna array in the X-Y plane. Infinite array models a single antenna element called the unit cell. Ground plane of the antenna specifies the boundaries of the unit cell. Antenna without a ground plane requires a reflector. The infinite array has a reflector-backed dipole as the default exciter antenna element. The default dimensions are chosen for an operating frequency of 1 GHz.

Creation

Description

infa = infiniteArray creates an infinite antenna array in the xy-plane.

infa = infiniteArray(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 pair arguments in any order as Name1=Value1, ..., NameN=ValueN. Properties you do not specify retain their default values.

Properties

Element — Type of individual antenna elements in unit cell

reflector-backed dipole antenna (default) | antenna object | pcbStack object

Type of individual antenna elements in a unit cell, specified as an antenna object or a pcbStack object. Back an antenna without a groundplane by a reflector. The ground plane size specifies the unit cell boundaries. Add vias to the infinite array by setting this property to a pcbStack object.

Note

You cannot set this property to a pcbStack object for these specifications:

• Disconnected array of metal-dielectric structures

• Antenna with multiple dielectric layers, edge feed, and different dimensions of the ground plane and dielectric substrate

• Antenna that you create with thePCB Antenna Designer app

Example: Element=reflector creates an infinite array of reflector antennas.

ScanAzimuth — Scan direction in azimuth plane

0 (default) | scalar

Scan direction in azimuth plane, specified as a scalar in degrees.

Example: ScanAzimuth=25

Data Types: double

ScanElevation — Scan direction in elevation plane

0 (default) | scalar

Scan direction in elevation plane, specified as a scalar in degrees.

Example: ScanElevation=80

Data Types: double

RemoveGround — Remove ground plane

false or 0 (default) | true or 1

Remove the ground plane of the reflector with air substrate, specified as a numeric or logical 1 (true) or 0 (false). When you specify 1, the object removes the ground plane. When you specify 0, the object does not remove the ground plane

Example: RemoveGround=1

Data Types: logical

Object Functions

numSummationTerms	Change number of summation terms for calculating periodic Green's function
show	Display antenna, array structures or shapes
info	Display information about antenna or array
axialRatio	Axial ratio of antenna
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
EHfields	Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedance	Input impedance of antenna; scan impedance of array
layout	Display array or PCB stack layout
mesh	Mesh properties of metal, dielectric antenna, or array structure
pattern	Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
patternAzimuth	Azimuth pattern of antenna or array
patternElevation	Elevation pattern of antenna or array
rcs	Calculate and plot radar cross section (RCS) of platform, antenna, or array
returnLoss	Return loss of antenna; scan return loss of array
sparameters	Calculate S-parameter for antenna and antenna array objects

Examples

Infinite Array of Reflector-Backed Dipoles

Create an infinite array of reflector-backed dipole as the unit cell. Scan the array at boresight. Visualize the unit cell.

infa = infiniteArray(Element=reflector,ScanAzimuth=0, ...
    ScanElevation=90);
show(infa)

Scan Impedance of Infinite Array

Calculate the scan impedance of an infinite array at 1 GHz. To calculate the impedance, scan the infinite array from boresight to horizon in the elevation plane.

infa = infiniteArray;
theta0deg = linspace(0,90,5);
zscan = nan(1,numel(theta0deg));    
    for j = 1:numel(theta0deg)
      infa.ScanElevation = theta0deg(j);
      zscan(1,j) = impedance(infa,1e9);
    end
 plot(zscan)

Calculate and Plot Scan Impedance at Bore Sight of Metal Infinite Array

Calculate the scan impedance at bore sight of a metal infinite array without ground plane at a frequency of 1 GHz.

h = infiniteArray(Element=reflector,ScanAzimuth=0, ...
    ScanElevation=90,RemoveGround=1);
zin = impedance(h,1e9)

zin = 51.2867 +26.4937i

impedance(h,1e9)

Plot Scan Impedance at Boresight of Metal-Dielectric Infinite Array

Plot the scan impedance at the boresight of a metal-dielectric infinite array at a frequency of 1 GHz.

ant = patchMicrostrip(Substrate=dielectric('Teflon'));
h = infiniteArray(Element=ant,ScanAzimuth=0,ScanElevation=90);
impedance(h,1e9)

Add Via to Infinite Array

This example shows how to add vias to an infinite array using a pcbStack object.

Create Infinite Array of pcbStack Objects

Create a pcbStack object with an FR4 dielectric substrate. Define the feed dimension and location. Define the via dimension and location. Create an infinite array of this pcbStack object.

f = 1e9;
lambda = 3e8/f;
p = pcbStack;
d = dielectric('FR4');
p.BoardThickness = d.Thickness;
p.Layers = {p.Layers{1} d p.Layers{2}};
p.FeedLocations = [0.02 0 1 3];
p.FeedDiameter = 1e-3;
p.ViaLocations = [0 0 1 3];
p.ViaDiameter = 1e-3;
ant = infiniteArray(Element=p)

ant = 
  infiniteArray with properties:

          Element: [1x1 pcbStack]
      ScanAzimuth: 0
    ScanElevation: 90
     RemoveGround: 0

View Array and Elevation Pattern

View and mesh the array. Plot the elevation pattern of the array at 1 GHz.

figure;
show(ant)

figure;
mesh(ant,MaxEdgeLength=lambda/20)  

figure;
patternElevation(ant,f)

References

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

Version History

Introduced in R2015b