EngeePhased.WidebandCollector
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Broadband signal collector.
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Description
System object EngeePhased.WidebandCollector simulates a broadband signal collector.
The collector converts the incident broadband wavefronts coming from the specified directions into signals for further processing. Wavefronts fall on antenna or microphone elements, antenna element arrays, or sublattices.
You can use this object to:
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Modeling of incoming signals of unpolarized fields.
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Simulation of incoming acoustic fields using unpolarized microphones. To do this, set the property to PropagationSpeed value corresponding to the environment
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Collecting fields on sublattices created by objects EngeePhased.ReplicatedSubarray and EngeePhased.PartitionedArray. You can point all antenna sublattices in one direction using the STEERANG rotation angle argument, or point each antenna sublattice in a different direction using the WS antenna sublattice weighting argument.
To collect the signals coming to the elements or grids, follow these steps:
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Create an object EngeePhased.WidebandCollector and set its properties.
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Call the object with arguments as if it were a function.
To learn more about how to work with system objects, see Engee System Objects.
Syntax
Creation
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collector = EngeePhased.WidebandCollector()— creates a broadband signal collector with default property values. -
collector = EngeePhased.WidebandCollector(Name=Value)— creates a broadband signal collector with specified properties in the form of a pairName=Value, whereName— the name of the property, andValue— the appropriate value. You can specify multiple pairs «name-value» the order of the pairs does not matter. Unspecified properties retain their default values.
Using
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Y = collector(X,ANG)— collects X signals coming from the directions specified in the ANG argument. The output signal Y contains the collected signals.
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Y = collector(___,W)— uses the W argument as the weighting coefficients of the antenna array or sublattice elements. To use this syntax, set the WeightsInputPort valuetrue. -
Y = collector(___,STEERANG)— uses the STEERANG argument as the angle of rotation of the sublattice. To use this syntax, set the Sensor the value of the grid that supports sublattices, and set the SubarraySteering grid property to"Phase"or"Time". -
Y = collector(___,WS)— uses the WS argument as the weights applied to each element inside each sublattice. To use this syntax, set the Sensor the value of the grid that supports sublattices, and set the SubarraySteering grid property to"Custom".
Arguments
Input arguments
X — input signal
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the complex matrix M on L | a complex tuple of length L
Details
Input signals specified as a complex matrix on , where — this is the number of samples of the signal, and — the number of angles of incidence. This argument represents the incoming fields.
| Типы данных |
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| Support for complex numbers |
Yes |
ANG — directions of arrival of signals
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the real matrix 2 on L
Details
The directions of arrival of the signals, given as a real matrix on . Each column specifies the direction of arrival in the form [AzimuthAngle;ElevationAngle].
The azimuthal angle should lie between −180° and 180°, inclusive. The angle of the seat should be in the range of −90° before 90°, inclusive.
The units of measurement are degrees.
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W — weight coefficients of elements or sublattices
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column vector N by 1
Details
Weight coefficients of elements or sublattices, specified as a complex column vector on , where — the number of antenna array elements (or sublattices, if supported).
Dependencies
To use this argument, set the property to WeightsInputPort value true.
| Типы данных |
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| Support for complex numbers |
Yes |
WS — weight coefficients of antenna sublattices
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the complex matrix NSE on N | array of cells 1 by N
Details
The weighting coefficients of the antenna sublattices elements, specified as a complex matrix on or a tuple of elements where — the number of sublattices. These weights are applied to the individual elements within the sublattice.
| Sublattice | Sublattice weights |
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All sublattices have the same dimensions. Then the weights of the sublattices form a matrix on , where is the number of elements in each sublattice, and — the number of sublattices. Each WS column defines the weights for the corresponding sublattice. |
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The sublattices may not have the same size. In this case, you can set the weights of the sublattices as:
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Dependencies
To use this argument, set the property to Sensor the value of the antenna array containing the sublattices, and set the SubarraySteering property of the array to "Custom".
| Типы данных |
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| Support for complex numbers |
Yes |
STEERANG — angle of rotation of the sublattice
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the real vector is 2 by 1
Details
The angle of rotation of the sublattice, set as a column vector of length .
The vector has the form [azimuthAngle;elevationAngle]. The azimuth angle should be in the range of −180° before 180°, inclusive. The angle of the seat should be from −90° before 90°, inclusive.
The units of measurement are degrees.
Dependencies
To use this argument, set the property to Sensor the value of the grid supporting the sublattices, and set the SubarraySteering grid property to "Phase" or "Time".
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Output arguments
Y — collected signal
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the complex matrix M by N
Details
The collected signal returned as a complex matrix on , where — the number of grid elements (or sublattices, if they are supported). Each column corresponds to the signal collected by the corresponding grid element (or the corresponding sublattices, if they are supported).
| Типы данных |
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| Support for complex numbers |
Yes |
Features
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SensorGainMeasure —
antenna gain of the antenna
String
Details
Antenna gain, given as "dB" (By default) or "dBi":
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"dB"— The input signal power is scaled according to the antenna power diagram (in dB) in the appropriate direction, and then combined. -
"dBi"— The input signal power is scaled according to the radiation pattern (in dBi) in the appropriate direction, and then combined. This option is useful when you want to compare the results with the values predicted by the basic radar equation, in which dbis are used to determine the antenna gain. Calculations using the usage option"dBi"are time-consuming, since to calculate the total radiated power of the antenna requires integration in all directions.
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PropagationSpeed —
signal propagation speed
Real number
Details
The propagation velocity of the signal, given as a positive scalar. The speed of light is used By default 299792458.
Units of measurement — m/s.
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SampleRate —
Sampling rate
Real number
Details
The sampling frequency of the signal, given as a positive scalar.
The ratio of the sampling rate to the pulse repetition rate (PRF) must be a positive integer.
The unit of measurement is Hz.
By default — 1.0e6.
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NumSubbands —
number of sub-ranges
Real number
Details
The number of processed sub-ranges, set as a positive integer.
By default — 64.
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WeightsInputPort —
Usage of weighting factors
Logical
Details
The usage of the weighting factors, given as false (By default) or true.
If this property is set to true, then the input argument W is used to specify the weighting coefficients. Weighting factors are applied to individual elements of the antenna array (or to sublattices, if they are supported).
# Sensor — antenna array element or antenna array
Details
Antenna array object, sublattice antennas, or antenna array element. The antenna array may contain sublattices.
Used By default EngeePhased.ULA.
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ModulatedInput —
modulated input
Logical
Details
Modulated input, specified as true (By default) or false.
Set this property to true to indicate that the input signal is demodulated at the carrier frequency.
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CarrierFrequency —
carrier frequency
Real number
Details
The carrier frequency, given as a positive real scalar.
Units of measurement — Hz.
By default — 1e9.
Additional Info
Processing of frequency sub-bands
Details
Subband processing divides the broadband signal into several subbands and applies narrowband processing to the signal in each subband. The signals of all sub-bands are combined to form an output signal.
When using broadband system objects or blocks, you need to specify the number of sub-ranges. , into which the broadband signal should be decomposed. The center frequencies and subband widths are automatically calculated from the total bandwidth and the number of subbands. The total frequency band is centered on the carrier or operating frequency . The total bandwidth is determined by the sampling rate . The width of the frequency sub-bands is . The central frequencies of the sub-bands are defined as:
Some system objects allow you to get the central frequencies of the sub-bands as output data when starting the object. The returned subband frequencies are ordered according to the order of the discrete Fourier transform. The frequencies above the carrier are displayed first, then the frequencies below the carrier.
An object EngeePhased.WidebandCollector uses a narrow-band phase approximation of the time delays on the receiving elements in the far zone for each subband.
Algorithms
System object EngeePhased.WidebandCollector performs the following for each signal:
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Decomposes the signal into several sub-bands.
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Uses a phase approximation of the time delays on the collecting elements in the far zone for each subrange.
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Rearranges the collected signals in all sub-bands to form an output signal.