phased.ArrayManifold

R2026b

Array manifold

Since R2026b

Description

The array manifold generates the response to incoming plane waves arriving at an array for each element as a function of azimuth, elevation, frequency, and polarization. The array manifold provides an alternative representation of an antenna array letting you use tabulated array manifold data with Phased Array System Toolbox™ functions and System objects. The array manifold models array properties including geometry, element patterns, and mutual coupling.

To use an array manifold:

1. Create the phased.ArrayManifold object and set its properties.

2. Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

Creation

Syntax

manifold = phased.ArrayManifold

manifold = phased.ArrayManifold(manifolddata,AzAngles,ElAngles,freqs)

manifold = phased.ArrayManifold(name=value)

Description

manifold = phased.ArrayManifold creates a phased.ArrayManifold System object™ with default property values.

manifold = phased.ArrayManifold(manifolddata,AzAngles,ElAngles,freqs) creates an array manifold with the Manifold property set to manifolddata, the AzimuthAngles property set to AzAngles, the ElevationAngles property set to ElAngles, and the FrequencyVector property set to freqs.

Example: manifold = phased.ArrayManifold(array,-180:180,-90:90,300e6)

manifold = phased.ArrayManifold(name=value) creates an array manifold System object with each property name set to a specified value. You can specify additional name-value arguments in any order as (name1=value1,...,nameN=valueN).

Example: manifold = phased.ArrayManifold(Manifold=array,AzimuthAngles=-85:85)

Properties

Unless otherwise indicated, properties are nontunable, which means you cannot change their values after calling the object. Objects lock when you call them, and the release function unlocks them.

If a property is tunable, you can change its value at any time.

For more information on changing property values, see System Design in MATLAB Using System Objects.

Manifold — Array manifold

ones(2,2,2) (default) | N-by-M-by-P-by-L complex-valued MATLAB^® array

Array manifold, specified as an N-by-M-by-P-by-L complex-valued MATLAB array. The object assumes that manifold elements lie on a regular azimuth-elevation-frequency grid.

• N is the number of AzimuthAngles grid points

• M is the number of ElevationAngles grid points

• P is the number of FrequencyVector grid points

• L is the number of array elements

For example, each slice of the manifold manifold(:,m,l,p) corresponds to manifold values for all azimuth angles for the m^th elevation and l^th frequency. All manifold values must be finite.

Data Types: single | double
Complex Number Support: Yes

AzimuthAngles — Azimuth angles grid

[-180 180] (default) | length-N real-valued vector

Azimuth angle points, specified as a real length-N vector. N represents the number of azimuth angles in the Manifold property. Azimuth angle values are in ascending order and must lie between -180° and 180°.

Specify the AzimuthAngles property as [] to indicate that the manifold does not depend on azimuth.

Example: [-45:45]

Data Types: single | double

ElevationAngles — Elevation angles grid

[-90 90] (default) | length-M real-valued vector

Elevation angles grid, specified as a real length-M vector. M represents the number of elevation grid points in the Manifold property. Elevation values are in ascending order and must lie between -90° and 90°.

Specify the ElevationAngles property as [] to indicate that the manifold does not depend on elevation.

Example: [-45:45]

Data Types: single | double

FrequencyVector — Frequency vector

[0 1e20] (default) | length-P real, positive-valued vector

Frequency vector, specified as a length-P real, positive-valued vector. P represents the number of frequencies in the Manifold property.

Specify the FrequencyVector property as empty [] to indicate that the manifold does not depend on frequency.

Data Types: single | double

Usage

Syntax

val = manifold(freq,angle)

Description

val = manifold(freq,angle) returns the array manifold value, val, evaluated at the specified frequencies freq and directions angle.

Input Arguments

freq — Frequencies

positive real-valued length-P vector

Frequencies, specified as a real positive-valued length-P vector. Each value must be finite and nonnegative. Units are in Hz.

Data Types: single | double

angle — Direction angles

real-valued 1-by-R vector | real-valued 2-by-R vector

Direction angles, specified as a real-valued, 1-by-R vector, or real-valued, 2-by-R matrix where R is the number of requested directions. Specify directions as azimuth angles only or as azimuth-elevation pairs.

• 1-by-R – Specify only the azimuth angles. The object assumes elevation is zero degrees.

• 2-by-R – Specify azimuth and elevation pairs in the form [azimuth;elevation].

Units are in degrees.

Data Types: single | double

Output Arguments

val — Manifold values

complex-valued MATLAB array

Manifold values at specified directions and frequencies, returned as a complex-valued MATLAB array.

Data Types: single | double

Object Functions

To use an object function, specify the System object as the first input argument. For example, to release system resources of a System object named obj, use this syntax:

release(obj)

Specific to phased.ArrayManifold

pattern	Plot array directivity and patterns from array manifold
directivity	Compute array manifold directivity
getNumElements	Number of elements in an array
isPolarizationCapable	Array polarization capability

Common to All System Objects

step	Run System object algorithm
release	Release resources and allow changes to System object property values and input characteristics
reset	Reset internal states of System object

Examples

Create and Evaluate Array Manifold

Create a phased.ArrayManifold System object™ and evaluate the manifold values in multiple directions.

First, set up the azimuth angle, elevation angle, and frequency grids.

az = -180:10:180;
el = -90:10:90;
fc = [0 1e9 2e9];
manval = complex(ones(numel(az),numel(el),numel(fc),8));

Create the array manifold.

man1 = phased.ArrayManifold(manval,az,el,fc);

Evaluate the manifold at two frequencies and two directions.

M1 = man1([0 1e9],[30 40; 0 10])

M1 = 
M1(:,:,1) =

     1     1
     1     1
     1     1
     1     1
     1     1
     1     1
     1     1
     1     1


M1(:,:,2) =

     1     1
     1     1
     1     1
     1     1
     1     1
     1     1
     1     1
     1     1

Create a second frequency-invariant manifold.

man2 = phased.ArrayManifold( ...
    manval(:,:,1,:),az,el,[]);

Frequency query values are ignored for frequency-invariant data.

M2 = man2([0 1e9 2e9],[0;0]);

Use the directivity object function to compute the directivity of the second manifold at az=-90 degrees and el=10 degrees.

[az(10),el(11)]

ans = 1×2

   -90    10

directivity(man2,fc(2),[az(10);el(11)])

ans = 
1.1025e-04

Using the pattern object function, plot the directivity pattern of the array manifold.

pattern(man2,fc(2)) 

Algorithms

You can use the array manifold with these System objects:

• phased.BeamscanEstimator2D

• phased.MUSICEstimator2D

• phased.MVDRBeamformer

• phased.MVDREstimator2D

• phased.PhaseShiftBeamformer

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2026b