EngeePhased.UCA
Uniform circular antenna array.
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Description
The EngeePhased.UCA system object models a uniform circular array (UCA). A UCA is formed from identical antenna element elements uniformly spaced on a circle.
To calculate the response of the array for the specified directions, follow the steps below:
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Define and configure a uniform circular array. Refer to. Syntax.
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Call the
step!method to compute the response according to the EngeePhased.UCA properties.
Syntax
Creation
The system object constructor can be called in the following ways:
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object = EngeePhased.UCAcreates a uniform circular array (UCA) consisting of five identical isotropic antenna elements, EngeePhased.IsotropicAntennaElement with by default property values. The elements are uniformly distributed on a circle of radius 0.5 m.Example:
sUCA = EngeePhased.UCA -
object = EngeePhased(Name=Value)creates a uniform circular array (UCA) with each specified property Name (name) set to the specified Value (value). You can specify additional arguments as a name-value pair in any order (Name1=Value1,…,NameN=ValueN).Example:
sUCA = EngeePhased.UCA(NumElements=3, Radius=7.5) -
object = EngeePhased(N,R)creates creates a uniform circular array (UCA) with a value ofNfor the NumElements property and a value ofRfor the Radius property. This syntax creates a uniform circular array consisting of isotropic antenna elements, EngeePhased.IsotropicAntennaElement.Example:
sUCA = EngeePhased.UCA(N,R) -
object = EngeePhased(N,R,Name=Value)creates a uniform circular array (UCA) with a value ofNfor property NumElements and a value ofRfor property Radius, and the other specified properties Name (name) set to the specified Value (value).Example:
sUCA = EngeePhased.UCA(N, R, ArrayNormal="x")
Properties
Element -
phased array element
IsotropicAntennaElement with property values by default | antenna, microphone or transducer element from Phased Array System Toolbox | antenna from Antenna Toolbox
Details
A phased array element specified as an antenna, acoustic element or transducer element from the Phased Array System Toolbox or an antenna from the Antenna Toolbox.
*Example: EngeePhased.CosineAntennaElement.
NumElements — number of grid elements
5 (by default) | A whole number greater than one
Details
The number of lattice elements specified as an integer greater than one.
*Example: 4
Radius -
array radius
0.5 (by default) | `positive scalar `
Details
The radius of the array, given as a positive scalar.
The unit of measurement is m.
*Example: 2.5
ArrayNormal
lattice normal direction
z (by default) | x | y
Details
Lattice normal direction specified as one of the x, y or z directions.
The elements of UCA lie in a plane orthogonal to the direction of the array normal. The element height vectors lie in the same plane and are directed radially outward from the origin.
| ArrayNormal property value | Elements positions |
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The elements of the array lie in the yz-plane. The pair of orthogonal vectors that form the element plane lie in the yz-plane and point outwards from the centre of the array. |
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The elements of the array lie in the zx-plane. The pair of orthogonal vectors that form the element plane lie in the zx plane and point outwards from the centre of the array. |
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The elements of the array lie in the xy plane. The pair of orthogonal vectors forming the element plane lie in the xy plane and point outward from the centre of the array. |
*Example: x
Taper -
the taper of the elements
1 (by default) | complex scalar | complex vector of rows 1 by N | complex vector of columns N by 1
Details
A contraction or weighting of elements given as a complex scalar, a vector of rows 1 by N or a vector of columns N by 1.
The value N is the number of elements of the array. Cones, also known as weights, are applied to each element of the antenna element array and change the amplitude and phase of the received data.
If Taper is a scalar, the same taper value is applied to all elements.
If Taper is a vector, each taper value is applied to the corresponding element of the antenna element.
*Example: [1 2 3 2 1]
Optional
*Algorithms.
A UCA is formed from N identical sensory elements uniformly spaced on a circle of radius R. The circle lies in the xy-plane of a local coordinate system whose origin lies at the centre of the circle.
The positions of the elements are determined relative to the local coordinate system of the array.
The circular array lies in the xy-plane of the coordinate system. The normal to the UCA plane lies along the positive z-axis. The elements are orientated so that their principal response directions (normals) point radially outward in the xy plane.
If the number of array elements is odd, the middle element lies on the x axis.
If the number of elements is even, the midpoint between the two middle elements lies on the x axis.
For an array of N elements, the azimuth angle of the position of element is defined as follows:
where
The azimuthal angle is defined as the angle in the xy plane from the x axis to the y axis.
Elevation angle is defined as the angle from the xy plane to the z axis. The angular distance between any two neighbouring elements is 360/H degrees. The values of azimuthal angles are given in degrees. Elevation angles for all elements of the array are zero.