installedAntenna

Installed antenna setup

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 automotive applications. The best examples of a platform in these applications are an aircraft, a ship, and an automobile respectively.

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(PropertyName=Value)

Description

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

ant = installedAntenna(PropertyName=Value)sets properties using one or more name–value arguments. PropertyName is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as PropertyName1=Value1,...,PropertyNameN=ValueN. Properties that you do not specify, retain their default values.

For example, p = platform(FileName='plate.stl'); ant = installedAntenna(Platform=p) uses the geometry in the 'plate.stl' file to create a platform for antenna installation and analysis.

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: platform(FileName='plate.stl')

Data Types: char

Element — Antenna or array to install on platform

antenna object | cell array of antenna objects | array object | cell array of array objects

Antenna or array to install on platform, specified as an object or cell array of objects from following:

• Antenna object from antenna catalog.

• Array object from: linearArray, rectangularArray, or circularArray.

antenna or array object, or a cell array of antenna or array objects. For multiple elements, you must specify ElementPosition for all the elements.

Note

Antennas with a dielectric substrate other than air are not supported as elements currently.

Example: dipole

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 in meters. For multiple antenna elements, the number of positions in ElementPosition must be equal to the number of elements specified in the Element property.

Example: [0 0 0.0050]

Data Types: double

Reference — Reference for positioning antenna elements

"feed" (default) | "origin"

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

Example: "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. For multiple antenna elements, the number of elements in FeedVoltage must be equal to the number of elements specified in the Element property.

Example: 2

Example: [2 5]

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. For multiple antenna elements, the number of elements in FeedPhase must be equal to the number of elements specified in the Element property.

Example: 50

Example: [50 60]

Data Types: double

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

SolverType — Solver for antenna analysis

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

Solver for antenna analysis, specified as either "MoM-PO" (Method of Moments-Physical Optics) or "MoM" (Method of Moments) or "FMM" (Fast Multipole Method).

Example: "MoM"

Data Types: string

Object Functions

axialRatio	Calculate and plot axial ratio of antenna or array
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
current	Current distribution on antenna or array surface
correlation	Correlation coefficient between two antennas in array
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
mesh	Generate and view mesh for antennas, arrays, and custom shapes
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
pattern	Plot radiation pattern of antenna, array, or embedded element of array
patternAzimuth	Azimuth plane radiation pattern of antenna or array
patternElevation	Elevation plane radiation pattern of antenna or array
patternSystem	Visualize radiation patterns of multiple antennas installed on platform
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
returnLoss	Calculate and plot return loss of antenna or scan return loss of array
show	Display antenna, array structures, shapes, or platform
solver	Access FMM solver settings for electromagnetic analysis
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

Installed Antenna Setup and Analysis

Create a default installed antenna.

ant = installedAntenna

ant = 
  installedAntenna with properties:

           Platform: [1×1 platform]
            Element: [1×1 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);

Radiation Patterns of Antennas Installed on Glider

Create a platform from the STL file containing the geometry information of a glider. View the platform.

plat = platform(FileName="glider.stl", Units="m");
figure
show(plat);

Design a regular and a circular microstrip patch antenna operating at 2GHz. Install these antennas on the glider wings. View the glider with installed antennas.

elem1 = design(patchMicrostrip, 2e9);
elem2 = design(patchMicrostripCircular, 2e9);
ant = installedAntenna(Platform=plat, Element={elem1, elem2},...
    ElementPosition=[-3.15 1.1 0.12; -3.15 -1.1 0.12]);
figure
show(ant)

Visualize the radiation patterns of the installed patch antennas.

figure
patternSystem(ant, 2e9, ElementNumber=1:2)

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