EngeePhased.CrossedDipoleAntennaElement
Crossed dipole antenna element.
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EngeePhased |
Description
The EngeePhased.CrossedDipoleAntennaElement system object models a crossed dipole antenna element that is used to generate a circularly polarised field. A crossed dipole antenna is formed from two orthogonal short dipoles.
By default, one dipole is located along the y axis and the other dipole is located along the z axis in the local antenna coordinate system.
You can rotate the antenna in the yz-plane using the RotationAngle property.
This antenna object generates fields with right-handed and left-handed circular polarisations, as well as a field with linear polarisation, controlled by the Polarization property. These fields propagate along the x axis (defined by the 0° azimuth and 0° elevation angles).
To calculate the response of the antenna element, follow the steps below:
-
Create an EngeePhased.CrossedDipoleAntennaElement object and set its properties.
-
Call the object with arguments as if it were a function.
Syntax
Creation
The system object constructor can be called in the following ways:
-
object = EngeePhased.CrossedDipoleAntennaElementcreates a crossed dipole antenna with by default property values. Example:antenna = EngeePhased.CrossedDipoleAntennaElement -
object = EngeePhased.CrossedDipoleAntennaElement(Name=Value)creates a crossed dipole antenna 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:antenna = EngeePhased.CrossedDipoleAntennaElement(RotationAngle=20, Polarization="LHCP")
Properties
FrequencyRange -
operating frequency range
[0 1e20] (by default) | non-negative real vector of strings 1 by 2
Details
The operating frequency range of the antenna, specified as a non-negative real vector of 1 by 2 rows in the form [LowerBound HigherBound]. The antenna element has no response outside the specified frequency range.
The units of measurement are Hz.
Data types: Float64.
RotationAngle -
rotation angle of crossed dipoles
0 (by default) | scalar between -45° and +45°
Details
The rotation angle of the crossed dipoles, specified as a scalar between -45° and +45°.
The rotation angle specifies the angle of rotation of two dipoles about the x axis.
The rotation angle is measured anti-clockwise around the x axis towards the origin. By default value 0° corresponds to the case when one dipole is located along the z axis and the other dipole is located along the y axis.
The units of measurement are degrees.
Data types: Float64.
Polarization -
transverse dipole field polarisation
RHCP (by default) | LHCP | Linear
Details
The polarisation of the field generated by the antenna is set as RHCP, LHCP or Linear.
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RHCPis a field with right-hand circular polarisation. The horizontal field has a 90° phase shift compared to the vertical field. -
LHCPis a field with left-hand circular polarisation. The horizontal field is lagged 90° behind the vertical field. -
Linear- linearly polarised field. The horizontal and vertical fields are in phase.
Data types: char | string
Arguments
Input
FREQ -
antenna element operating frequency
non-negative scalar | non-negative real vector 1 on L lines
Details
The operating frequency of the antenna element given as a non-negative scalar or a non-negative real vector 1 on L lines.
The units of measurement are Hz.
FREQ must lie within the range of values specified by the FrequencyRange property of the element.
Otherwise, the element does not respond and returns as -Inf.
*Example: [1e8 2e6].
Data types: Float64.
ANG -
azimuth and altitude angles of response directions
` real vector of rows 1 on M` | ` real matrix 2 on M`
Details
Azimuth and elevation angles of response 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 must lie in the range from -180° to 180° inclusive. Elevation angle shall 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. Elevation angle is the angle between the direction vector and the xy plane. This angle is positive when measured in the z-axis direction.
*Example: [110 125; 15 10]
Data types: Float64.
Optional
*Algorithms.
The total response of an antenna element with crossed dipoles is the combination of its frequency and spatial characteristics.
The EngeePhased.CrossedDipoleAntennaElement system object calculates both responses using nearest neighbour interpolation and then multiplies them to obtain the summed response.