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phased.PartitionedArray System object

Package: phased

Phased array partitioned into subarrays

Description

The PartitionedArray object represents a phased array that is partitioned into one or more subarrays.

To obtain the response of the subarrays in a partitioned array:

  1. Define and set up your partitioned array. See Construction.

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

You can also specify a PartitionedArray object as the value of the SensorArray or Sensor property of objects that perform beamforming, steering, and other operations.

    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.PartitionedArray creates a partitioned array System object, H. This object represents an array that is partitioned into subarrays.

H = phased.PartitionedArray(Name,Value) creates a partitioned array 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

Array

Array aperture

Specify a phased array as a phased.ULA, phased.URA, or phased.ConformalArray object.

Default: phased.ULA('NumElements',4)

SubarraySelection

Subarray definition matrix

Specify the subarray selection as an M-by-N matrix. M is the number of subarrays and N is the total number of elements in the array. Each row of the matrix indicates which elements belong to the corresponding subarray. Each entry in the matrix is 1 or 0, where 1 indicates that the element appears in the subarray and 0 indicates the opposite. Each row must contain at least one 1.

The phase center of each subarray is at the subarray geometric center. The SubarraySelection and Array properties determine the geometric center.

Default: [1 1 0 0; 0 0 1 1]

SubarraySteering

Subarray steering method

Specify the method of steering the subarray as one of 'None' | 'Phase' | 'Time'.

Default: 'None'

PhaseShifterFrequency

Subarray phase shifter frequency

Specify the operating frequency of phase shifters that perform subarray steering. The property value is a positive scalar in hertz. This property applies when you set the SubarraySteering property to 'Phase'.

Default: 300e6

NumPhaseShifterBits

Number of phase shifter quantization bits

The number of bits used to quantize the phase shift component of beamformer or steering vector weights. Specify the number of bits as a non-negative integer. A value of zero indicates that no quantization is performed.

Default: 0

Methods

cloneCreate partitioned array with same property values
collectPlaneWaveSimulate received plane waves
directivityDirectivity of partitioned array
getElementPositionPositions of array elements
getNumElementsNumber of elements in array
getNumInputsNumber of expected inputs to step method
getNumOutputsNumber of outputs from step method
getNumSubarraysNumber of subarrays in array
getSubarrayPositionPositions of subarrays in array
isLockedLocked status for input attributes and nontunable properties
isPolarizationCapablePolarization capability
patternPlot partitioned array directivity, field, and power patterns
patternAzimuthPlot partitioned array directivity or pattern versus azimuth
patternElevationPlot partitioned array directivity or pattern versus elevation
plotResponsePlot response pattern of array
releaseAllow property value and input characteristics changes
stepOutput responses of subarrays
viewArrayView array geometry

Examples

expand all

Plot the azimuth response of a 4-element ULA partitioned into two 2-element ULA's. The element spacing is one-half wavelength.

Create the ULA, and partition it into two 2-element ULA's.

sULA = phased.ULA('NumElements',4,'ElementSpacing',0.5);
sPA = phased.PartitionedArray('Array',sULA,...
    'SubarraySelection',[1 1 0 0;0 0 1 1]);

Plot the azimuth response of the array. Assume the operating frequency is 1 GHz and the propagation speed is the speed of light.

fc = 1e9;
pattern(sPA,fc,[-180:180],0,'Type','powerdb',...
    'CoordinateSystem','polar',...
    'Normalize',true)

Create a 4-element ULA. Then partition the ULA into two 2-element ULAs. Then, calculate the response at boresight of a 4-element ULA partitioned into two 2-element ULAs.

sULA = phased.ULA('NumElements',4,'ElementSpacing',0.5);
sPA = phased.PartitionedArray('Array',sULA,...
   'SubarraySelection',[1 1 0 0;0 0 1 1]);

Calculate the response at 1 GHz. The signal propagation speed is the speed of light.

fc = 1e9;
resp = step(sPA,fc,[0;0],physconst('LightSpeed'))
resp =

     2
     2

Related Examples

References

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

Introduced in R2012a

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