EngeePhased.ULA
Uniform linear antenna array (ULA).
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Description
The EngeePhased.ULA system object models a uniform linear antenna array (ULA) and calculates its response.
To calculate the response for each antenna array element for the specified directions, follow the steps below:
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Create an EngeePhased.ULA object and set its properties.
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Call the object with arguments as if it were a function.
Syntax
Create
You can call the system object constructor in the following ways:
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object = EngeePhased.ULAcreates a uniform linear antenna array (ULA) formed from identical isotropic phased array sensor elements with by default property values. The origin of the local coordinate system is the phase centre of the antenna array. The positive x axis is the direction normal to the antenna array, and the antenna array elements are located along the y axis.Example:
array = EngeePhased.ULA -
object = EngeePhased.ULA(Name=Value)creates a uniform linear antenna array (ULA) 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:
array = EngeePhased.ULA(ElementSpacing=1.5,ArrayAxis="z") -
object = EngeePhased.URA(N,D,Name=Value)creates a uniform linear antenna array (ULA) with the NumElements property set toN, the ElementSpacing property set toD, and the other specified properties Name (name) set to the specified Value (value).NandDare value-only arguments. When specifying a value-only argument, all preceding value-only arguments must be specified. The arguments of the Name-Value pair can be specified in any order.Example:
array = EngeePhased.ULA(N,D,NumElements=5)
Properties
Element -
phased antenna array element
`IsotropicAntennaElement with property values by default ` | `antenna, acoustic element or transducer element from Phased Array System Toolbox ` | `antenna array from Antenna Toolbox `
Details
A phased array element specified as an antenna element, acoustic element or transducer from the Phased Array System Toolbox or an antenna array from the Antenna Toolbox.
*Example: EngeePhased.CosineAntennaElement.
NumElements -
number of antenna array elements
2 (by default) | positive integer
Details
The number of elements of a linear antenna array, specified as a positive integer.
Data types: Float64
ElementSpacing -
antenna array element spacing
0.5 (by default) | `positive scalar `
Details
The distance between two neighbouring elements of a linear antenna array, specified as a positive scalar.
The unit of measurement is m.
Data types: Float64
ArrayAxis -
linear antenna array axis
y (by default) | x | z
Details
Linear antenna array axis specified as x, y or z.
The elements of the linear antenna array are located along the selected axis of the coordinate system. The antenna array axis defines the direction along which the normal vectors of the elements are directed.
| ArrayAxis property value | Element normal direction |
|---|---|
|
azimuth = 90°, elevation = 0° (y axis) |
|
azimuth = 0°, height = 0° (x axis) |
|
azimuth = 0°, altitude = 0° (x axis) |
Taper -
cones 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 of the elements of a linear antenna array, given as a complex scalar, a complex vector of rows 1 by N or a complex vector of columns N by 1. N represents the number of antenna array elements. Cones, also known as weighting factors, are applied to each antenna element of a linear antenna array and change the amplitude and phase of the received data.
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If Taper is a scalar, the same taper value is applied to all elements.
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If Taper is a vector, each taper value is applied to the corresponding antenna element.
Data types: Float64
Entry
freq -
operating frequency of the antenna element
positive real vector 1 on L lines
Details
The operating frequency of the antenna element given as a positive real vector 1 on L lines.
The units of measurement are Hz.
Data types: Float64
ang -
azimuthal and altitude angles of response directions
` real vector of rows 1 on M` | ` real matrix 2 on M`
Details
Azimuth and elevation angles of the answer directions given as a real vector of strings 1 by M or a real matrix 2 by M, where M is the number of angular directions.
The units of measurement are degrees.
The azimuth angle shall lie in the range from -180° to 180° inclusive. The elevation angle must lie in the range from -90° to 90° inclusive.
If ang is a vector 1 on M, each element specifies an azimuthal angle of direction. In this case, the corresponding elevation angle is assumed to be zero.
If ang is a matrix 2 on M, each column of the matrix specifies a direction in the form [azimuth;elevation].
The azimuth angle is the angle between the x axis and the projection of the direction vector onto the xy plane. This angle is positive when measured from the x axis towards the y axis. The elevation angle is the angle between the direction vector and the xy plane. This angle is positive when measured in the direction of the z axis.
Data types: Float64