installedAntenna

Installed antenna setup

Since R2019a

Description

The installedAntenna object creates an installed antenna setup that enables you to mount antennas on a platform for analysis.

Installed antenna analysis involves an electrically large structure called a platform. Around this platform, different antenna elements are placed. You can analyze the effects of the platform on the antenna performance. Installed antenna analysis is commonly used in aerospace, defense, and auto applications. The platforms in this case are planes, ships, or inside the bumper of a car.

Another common application of installed antenna analysis is to determine the interference of different antennas placed on a large platform.

Note

installedAntenna only models pure metal structures.

Creation

Syntax

ant = installedAntenna

ant = installedAntenna(Name,Value)

Description

ant = installedAntenna creates an installed antenna setup. The default setup has a rectangular reflector in the X-Y plane as the platform with a dipole as the antenna. The dimensions of the dipole antenna are chosen for an operating frequency of 1 GHz.

ant = installedAntenna(Name,Value) sets properties using one or more name-value pairs. For example, ant = installedAntenna('Element',monopole) creates an installed antenna setup using monopole as the antenna.

Output Arguments

ant — Installed antenna setup

installedAntenna object

Installed antenna setup, returned as an installedAntenna object.

Properties

Platform — Platform object file

platform object

Platform object file, specified as a platform object.

Example: plat = platform('FileName','plate.stl'); ant = installedAntenna('Platform',plat) This code creates a platform object called plat and uses it for installed antenna analysis.

Example: plat = platform('FileName','plate.stl'); ant = installedAntenna;ant.Platform = plat This code creates a platform object called plat and uses it for installed antenna analysis.

Data Types: char

Element — Single or multiple antenna elements

antenna object | vector of antenna objects

Single or multiple antennas, specified as an antenna object or a vector of antenna objects.

Example: d = dipole; ant = installedAntenna('Element',d) This code creates a dipole antenna object and uses it for installed antenna analysis.

Example: d = dipole; ant = installedAntenna;ant.Element=d This code creates a dipole antenna object and uses it for installed antenna analysis.

Example: ant = installedAntenna('Element',{discone,monocone},'ElementPosition',[0.1 0.1 0.5; -0.1 -0.1 0.5]) This code creates discone and monocone antenna objects for installed antenna analysis.

Data Types: char

ElementPosition — Position of feed or origin of each antenna element

[0 0 0.0750] (default) | vector of [x,y,z] coordinates

Position of the feed or the origin of each antenna element, specified as a vector of [x,y,z] coordinates with each element unit in meters.

Example: 'ElementPosition',[0 0 0.0050]

Example: ant.ElementPosition = [0 0 0.0050]

Data Types: double

Reference — Reference for positioning antenna elements

'feed' (default) | 'origin'

Reference for positioning the antenna elements, specified as 'feed' or 'origin'.

Example: 'Reference','origin'

Example: ant.Reference = 'origin'

Data Types: string

FeedVoltage — Excitation amplitude for antenna elements

1 (default) | vector

Excitation amplitude for the antenna elements, specified as a scalar vector in volts.

Example: 'FeedVoltage',2

Example: ant.FeedVoltage = 2

Data Types: double

FeedPhase — Phase shift of each antenna element

0 (default) | vector

Phase shift of each antenna element, specified as a scalar or vector in degrees.

Example: 'FeedPhase',50

Example: ant.FeedPhase = 50

Data Types: double

Tilt — Tilt angle of antenna

0 (default) | scalar | vector

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: 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

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates | 'X' | 'Y' | 'Z'

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: TiltAxis = 'Z'

Data Types: double

SolverType — Solver for antenna analysis

'MoM-PO' (default) | 'MoM' | 'FMM'

Solver for antenna analysis, specified as the comma-separated pair consisting of 'SolverType' and 'MoM-PO' (Method of Moments-Physical Optics) or 'MoM' (Method of Moments) or 'FMM' (Fast Multipole Method).

Example: 'SolverType','MoM'

Data Types: char

Object Functions

show	Display antenna, array structures or shapes
solver	Access FMM solver for electromagnetic analysis
axialRatio	Axial ratio of antenna
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
current	Current distribution on antenna or array surface
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
mesh	Mesh properties of metal, dielectric antenna, or array structure
meshconfig	Change mesh mode of antenna 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
returnLoss	Return loss of antenna; scan return loss of array
sparameters	Calculate S-parameter for antenna and antenna array objects
vswr	Voltage standing wave ratio of antenna

Examples

Installed Antenna Setup and Analysis

Create a default installed antenna.

ant = installedAntenna

ant = 
  installedAntenna with properties:

           Platform: [1x1 platform]
            Element: [1x1 dipole]
    ElementPosition: [0 0 0.0750]
          Reference: 'feed'
        FeedVoltage: 1
          FeedPhase: 0
               Tilt: 0
           TiltAxis: [1 0 0]
         SolverType: 'MoM-PO'

show(ant);

Calculate the impedance of the antenna.

figure;
impedance(ant, linspace(950e6, 1050e6, 51));

Visualize the pattern of the antenna.

figure;
pattern(ant, 1e9);

Algorithms

Solver Recommendations for Installed Antenna Analysis

Hybrid MoM PO Solver

The default solver for installed antenna analysis is the hybrid MoM-PO ( Method of moments and physical optics) solver. This is a hybrid solver, with less stringent requirements on the mesh. This approach does not have full-wave accuracy since the electrically large portion of the geometry is handled using the physical optics approach. For more information on this solver see, Hybrid MoM-PO Method for Metal Antennas with Large Scatterers.

FMM Solver

For full wave accuracy in installed antenna analysis you can use the FMM (fast multiple method) solver. This solver does not fill and store a matrix of interactions and enables the solution of large structures which is not possible when using the MoM solver. For open geometries, this solver builds a preconditioner matrix internally. The preconditioner matrix is sparse but might be less sparse for larger structures. Preconditioner matrices are not built for closed geometries. When using the FMM, you have an option to use the solver object to set up the number of iterations and the relative error. In some circumstances it might be useful to study the nature of the problem and its convergence characteristics by reducing the number of iterations or the relative error initially or both. The FMM solver does need approximately 10 elements per wavelength in the mesh. The number of elements does impact the convergence of the solution. For more information on FMM solvers, see Fast Multipole Method for Large Structures.

MoM Solver

For wavelength and sub-wavelength scale structures, with or without dielectric you can use an MoM (method of moments)solver. For more information on MoM solver, see Method of Moments Solver for Metal Structures and Method of Moments Solver for Metal and Dielectric Structures.

Version History

Introduced in R2019a