phased.HeterogeneousURA

Heterogeneous uniform rectangular array

Description

The HeterogeneousURA object constructs a heterogeneous uniform rectangular array (URA).

To compute the response for each element in the array for specified directions:

1. Define and set up your uniform rectangular array. See Construction.

2. Call step to compute the response according to the properties of phased.HeterogeneousURA. The behavior of step is specific to each object in the toolbox.

Note

Starting in R2016b, instead of using the step method to perform the operation defined by the System object™, you can call the object with arguments, as if it were a function. For example, y = step(obj,x) and y = obj(x) perform equivalent operations.

Construction

H = phased.HeterogeneousURA creates a heterogeneous uniform rectangular array (URA) System object, H. This object models a heterogeneous URA formed with sensor elements whose pattern may vary from element to element. Array elements are distributed in the yz-plane in a rectangular lattice. An M-by-N heterogeneous URA has M rows and N columns. The array boresight direction is along the positive x-axis. The default array is a 2-by-2 URA of isotropic antenna elements.

H = phased.HeterogeneousURA(Name,Value) creates the object, H, with each specified property Name set to the specified Value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

Properties

ElementSet	Set of elements used in the array Set of elements used in the sensor array, specified as a row MATLAB cell array. Elements specified in the ElementSet property must be either Phased Array System Toolbox™ antennas, microphones, or transducers System objects or Antenna Toolbox™ System object. In addition, all specified antenna elements must have the same polarization capability. Default: One cell containing one isotropic antenna element
ElementIndices	Elements location assignment This property specifies the mapping of elements in the array. The property assigns elements to their locations in the array using the indices into the ElementSet property. The value of ElementIndices must be an M-by-N matrix. In this matrix, M represents the number of rows and N represents the number of columns. Rows are along y-axis and columns are along z-axis of the local coordinate system. The values in the matrix specified by ElementIndices should be less than or equal to the number of entries in the ElementSet property. Default: [1 1;1 1]
ElementSpacing	Element spacing A 1-by-2 vector or a scalar containing the element spacing (in meters) of the array. If ElementSpacing is a 1-by-2 vector, it is in the form of [SpacingBetweenRows,SpacingBetweenColumns]. See Spacing Between Columns and Spacing Between Rows. If ElementSpacing is a scalar, both spacings are the same. Default: [0.5 0.5]
Lattice	Element lattice Specify the element lattice as one of 'Rectangular' | 'Triangular'. When you set the Lattice property to 'Rectangular', all elements in the heterogeneous URA are aligned in both row and column directions. When you set the Lattice property to 'Triangular', the elements in even rows are shifted toward the positive row axis direction by a distance of half the element spacing along the row. Default: 'Rectangular'
ArrayNormal	Array normal direction Array normal direction, specified as one of 'x', 'y', or 'z'. URA elements lie in a plane orthogonal to the selected array normal direction. Element boresight directions point along the array normal direction ArrayNormal Property Value Element Positions and Boresight Directions 'x' Array elements lie on the yz-plane. All element boresight vectors point along the x-axis. 'y' Array elements lie on the zx-plane. All element boresight vectors point along the y-axis. 'z' Array elements lie on the xy-plane. All element boresight vectors point along the z-axis. Default: 'x'
Taper	Element tapers Element tapers, specified as a complex-valued scalar, or a complex-valued 1-by-MN row vector, MN-by-1 column vector, or M-by-N matrix. Tapers are applied to each element in the sensor array. Tapers are often referred to as element weights. M is the number of elements along the z-axis, and N is the number of elements along y-axis. M and N correspond to the values of [NumberofRows, NumberOfColumns] in the Size property. If Taper is a scalar, the same taper value is applied to all elements. If the value of Taper is a vector or matrix, taper values are applied to the corresponding elements. Tapers are used to modify both the amplitude and phase of the received data. Default: 1

Methods

Specific to phased.HeterogeneousURA Object
beamwidth	Compute and display beamwidth of an array
collectPlaneWave	Simulate received plane waves
directivity	Directivity of heterogeneous uniform rectangular array
getElementNormal	Normal vector to array elements
getElementPosition	Positions of array elements
getNumElements	Number of elements in array
getTaper	Array element tapers
isPolarizationCapable	Polarization capability
pattern	Plot heterogeneous URA directivity and power pattern
patternAzimuth	Plot heterogeneous URA directivity or pattern versus azimuth
patternElevation	Plot heterogeneous URA array directivity or pattern versus elevation
perturbations	Perturbations defined on phased array
perturbedArray	Apply perturbations to phased array
perturbedPattern	Compute and plot azimuth pattern of perturbed array
sidelobelevel	Peak and integrated sidelobe levels
step	Output responses of array elements
viewArray	View array geometry

Common to All System Objects
release	Allow System object property value changes

Examples

Azimuth Pattern of 3-by-2 Heterogeneous URA

Construct a 3-by-2 heterogeneous URA with a rectangular lattice, and find the response of each element at 30 degrees azimuth and 0 degrees elevation. Assume the operating frequency is 1 GHz.

antenna1 = phased.CosineAntennaElement('CosinePower',1.5);
antenna2 = phased.CosineAntennaElement('CosinePower',1.8);
array = phased.HeterogeneousURA('ElementSet',{antenna1,antenna2}, ...
    'ElementIndices',[1 1; 2 2; 1 1]);
fc = 1e9;
ang = [30;0];
resp = array(fc,ang)

resp = 6×1

    0.8059
    0.7719
    0.8059
    0.8059
    0.7719
    0.8059

Plot the azimuth pattern of the array.

c = physconst('LightSpeed');
pattern(array,fc,[-180:180],0,'PropagationSpeed',c, ...
    'CoordinateSystem','polar','Type','powerdb','Normalize',true)

Draw Heterogeneous Triangular Lattice Array

Construct a 3-by-3 heterogeneous URA with a triangular lattice. The element spacing is 0.5 meter. Display the array shape.

elem1 = phased.CosineAntennaElement('CosinePower',1.5);
elem2= phased.CosineAntennaElement('CosinePower',1.8);
array = phased.HeterogeneousURA( ...
    'ElementSet',{elem1,elem2}, ...
    'ElementIndices',[1 1 1; 2 2 2; 1 1 1], ...
    'Lattice','Triangular');
viewArray(array)

More About

Spacing Between Columns

The spacing between columns is the distance between adjacent elements in the same row.

Spacing Between Rows

The spacing between rows is the distance along the column axis direction between adjacent rows.

References

[1] Brookner, E., ed. Radar Technology. Lexington, MA: LexBook, 1996.

[2] Brookner, E., ed. Practical Phased Array Antenna Systems. Boston: Artech House, 1991.

[3] Mailloux, R. J. “Phased Array Theory and Technology,” Proceedings of the IEEE, Vol., 70, Number 3, 1982, pp. 246–291.

[4] Mott, H. Antennas for Radar and Communications, A Polarimetric Approach. New York: John Wiley & Sons, 1992.

[5] Van Trees, H. Optimum Array Processing. New York: Wiley-Interscience, 2002.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• pattern, patternAzimuth, patternElevation, plotResponse, and viewArray methods are not supported.

• See System Objects in MATLAB Code Generation (MATLAB Coder).

Version History

Introduced in R2013a