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phased.UCA

Uniform circular array

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Description

Thephased.UCASystem object™ creates auniform circular array(UCA). A UCA is formed from identical sensor elements equally spaced around a circle.

To compute the response for the array for specified directions:

  1. Define and set up your uniform circular array. SeeConstruction.

  2. Callstepto compute the response according to the properties ofphased.UCA. The behavior ofstepis specific to each object in the toolbox.

Note

Starting in R2016b, instead of using thestep方法进行加工ation defined by the System object, you can call the object with arguments, as if it were a function. For example,y = step(obj,x)andy = obj(x)perform equivalent operations.

Construction

sUCA = phased.UCAcreates a uniform circular array (UCA) System object,sUCA, consisting of five identical isotropic antenna elements,phased.IsotropicAntennaElement. The elements are equally spaced around a circle of radius 0.5 meters.

sUCA = phased.UCA(Name,Value)creates a System object,sUCA,每个指定属性名称设置为specified Value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

sUCA = phased.UCA(N,R)creates a UCA System object,sUCA, with theNumElementsproperty set toNand theRadiusproperty set toR. This syntax creates a UCA consisting of isotropic antenna elements,phased.IsotropicAntennaElement.

sUCA = phased.UCA(N,R,Name,Value)creates a UCA System object,sUCA, with theNumElementsproperty set toN,Radiusproperty set toR, and other specified property Names set to the specified Values.

Properties

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Sensor array element, specified as a Phased Array System Toolbox antenna or microphone element System object. You can specify antenna elements which do or do not support polarization.

Example:phased.ShortDipoleAntennaElement()

Number of array elements, specified as an integer greater than one.

Example:3

Array radius, specified as a positive scalar in meters.

Example:2.5

Array normal direction, specified as one of'x','y', or'z'. UCA elements lie in a plane orthogonal to the array normal direction. Element boresight vectors lie in the same plane and point radially outward from the origin.

ArrayNormal Property Value Element Positions and Boresight Directions
'x' Array elements lie on theyz-plane. All element boresight vectors lie in theyz-plane and point outward from the array center.
'y' Array elements lie on thezx-plane. All element boresight vectors lie in thezx-plane and point outward from the array center.
'z' Array elements lie on thexy-plane. All element boresight vectors lie in thexy-plane and point outward from the array center.

Example:'y'

Element tapering or weighting, specified as a complex-valued scalar, 1-by-Nrow vector, orN-by-1 column vector. The quantityNrepresents the number of elements of the array. Tapers, also known as weights, are applied to each sensor element in the sensor array and modify both the amplitude and phase of the received data. If'Taper'is a scalar, the same taper value is applied to all element. If'Taper'is a vector, each taper value is applied to the corresponding sensor element.

Example:[1 2 3 2 1]

Methods

Specific tophased.URAObject
beamwidth

Compute and display beamwidth of an array
collectPlaneWave

Simulate received plane waves
directivity

Directivity of uniform circular array
getElementNormal

Normal vectors for array elements
getElementPosition

Positions of array elements
getElementSpacing

Spacing between array elements
getNumElements

Number of elements in array
getTaper

Array element tapers
isPolarizationCapable

Polarization capability
pattern

Plot UCA array pattern
patternAzimuth

Plot UCA array directivity or pattern versus azimuth
patternElevation

Plot UCA array directivity or pattern versus elevation
step

Output responses of array elements
viewArray

View array geometry
Common to All System Objects
release

Allow System object property value changes

Examples

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Open Live Script

Create an 11-element uniform circular array (UCA) having a 1.5 m radius and operating at 500 MHz. The array consists of short-dipole antenna elements. First, display the vertical component of the response at 45 degrees azimuth and 0 degrees elevation. Then plot the azimuth and elevation directivities.

antenna = phased.ShortDipoleAntennaElement(...'FrequencyRange',[50e6,1000e6],...'AxisDirection','Z'); array = phased.UCA('NumElements',11,'Radius',1.5,'Element',antenna); fc = 500e6; ang = [45;0]; resp = array(fc,ang); disp(resp.V)
-1.2247 -1.2247 -1.2247 -1.2247 -1.2247 -1.2247 -1.2247 -1.2247 -1.2247 -1.2247 -1.2247

Display the azimuth directivity pattern at 500 MHz for azimuth angles between -180 and 180 degrees.

c = physconst('LightSpeed'); pattern(array,fc,[-180:180],0,'Type','directivity','PropagationSpeed',c)

Display the elevation directivity pattern at 500 MHz for elevation angles between -90 and 90 degrees.

pattern(array,fc,[0],[-90:90],'Type','directivity','PropagationSpeed',c)

Algorithms

A UCA is formed fromNidentical sensor elements equally spaced around a circle of radiusR. The circle lies in thexy-plane of the local coordinate system whose origin lies at the center of the circle. The positions of the elements are defined with respect to the local array coordinate system. The circular array lies in thexy-plane of the coordinate system. The normal to the UCA plane lies along the positivez-axis. The elements are oriented so that their main response directions (normals) point radially outward in thexy-plane.

If the number of elements of the array is odd, the middle element lies on thex-axis. If the number of elements is even, the midpoint between the two middle elements lies on thex-axis. For an array ofNelements, the azimuth angle of the position of thenthelement is given by

φ n = ( − ( N − 1 ) / 2 + n − 1 ) ⋅ 360 / N n = 1 , … , N

The azimuth angle is defined as the angle, in thexy-plane, from thex-axis toward they-axis. The elevation angle is defined as the angle from thexy-plane toward thez-axis. The angular distance between any two adjacent elements is360/Ndegrees. Azimuth angle values are in degrees. Elevation angles for all array elements are zero.

References

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

[2] Van Trees, H.Optimum Array Processing. New York: Wiley-Interscience, 2002, pp. 274–304.

Extended Capabilities

See Also

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Topics

Introduced in R2015a

Phased Array System Toolbox Documentation

金宝app

Exploring Hybrid Beamforming Architectures for 5G Systems

Exploring Hybrid Beamforming Architectures for 5G Systems

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