Documentation |
Y = step(H,X,ANG)
Y = step(H,X,ANG,LAXES)
Y = step(H,X,ANG,WEIGHTS)
Y = step(H,X,ANG,STEERANGLE)
Y = step(H,X,ANG,LAXES,WEIGHTS,STEERANGLE)
Y = step(H,X,ANG) collects signals X arriving from directions ANG. The collection process depends on the Wavefront property of H, as follows:
If Wavefront has the value 'Plane', each collecting element collects all the far field signals in X. Each column of Y contains the output of the corresponding element in response to all the signals in X.
If Wavefront has the value 'Unspecified', each collecting element collects only one impinging signal from X. Each column of Y contains the output of the corresponding element in response to the corresponding column of X. The 'Unspecified' option is available when the Sensor property of H does not contain subarrays.
Y = step(H,X,ANG,LAXES) uses LAXES as the local coordinate system axes directions. This syntax is available when you set the EnablePolarization property to true.
Y = step(H,X,ANG,WEIGHTS) uses WEIGHTS as the weight vector. This syntax is available when you set the WeightsInputPort property to true.
Y = step(H,X,ANG,STEERANGLE) uses STEERANGLE as the subarray steering angle. This syntax is available when you configure H so that H.Sensor is an array that contains subarrays and H.Sensor.SubarraySteering is either 'Phase' or 'Time'.
Y = step(H,X,ANG,LAXES,WEIGHTS,STEERANGLE) combines all input arguments. This syntax is available when you configure H so that H.WeightsInputPort is true, H.Sensor is an array that contains subarrays, and H.Sensor.SubarraySteering is either 'Phase' or 'Time'.
Note: H specifies the System object™ on which to run this step method. The object performs an initialization the first time the step method is executed. This initialization locks nontunable properties and input specifications, such as dimensions, complexity, and data type of the input data. If you change a nontunable property or an input specification, the System object issues an error. To change nontunable properties or inputs, you must first call the release method to unlock the object. |
H |
Collector object. | ||||||
X |
Arriving signals. Each column of X represents a separate signal. The specific interpretation of X depends on the Wavefront property of H.
| ||||||
ANG |
Incident directions of signals, specified as a two-row matrix. Each column specifies the incident direction of the corresponding column of X. Each column of ANG has the form [azimuth; elevation], in degrees. The azimuth angle must be between –180 and 180 degrees, inclusive. The elevation angle must be between –90 and 90 degrees, inclusive. | ||||||
LAXES |
Local coordinate system. LAXES is a 3-by-3 matrix whose columns specify the local coordinate system's orthonormal x, y, and z axes, respectively. Each axis is specified in terms of [x;y;z] with respect to the global coordinate system. This argument is only used when the EnablePolarization property is set to true. | ||||||
WEIGHTS |
Vector of weights. WEIGHTS is a column vector of length M, where M is the number of collecting elements. Default: ones(M,1) | ||||||
STEERANGLE |
Subarray steering angle, specified as a length-2 column vector. The vector has the form [azimuth; elevation], in degrees. The azimuth angle must be between –180 and 180 degrees, inclusive. The elevation angle must be between –90 and 90 degrees, inclusive. |
Y |
Collected signals. Each column of Y contains the output of the corresponding element. The output is the response to all the signals in X, or one signal in X, depending on the Wavefront property of H. |
Construct a 4-element uniform linear array. The array operating frequency is 1 GHz. The array element spacing is half the operating frequency wavelength. Model the collection of a 200-Hz sine wave incident on the array from 45 degrees azimuth, 10 degrees elevation from the far field.
fc = 1e9; lambda = physconst('LightSpeed')/fc; hULA = phased.ULA('NumElements',4,'ElementSpacing',lambda/2); t = linspace(0,1,1e3); x = cos(2*pi*200*t)'; % construct the collector object. hc = phased.Collector('Sensor',hULA,... 'PropagationSpeed',physconst('LightSpeed'),... 'Wavefront','Plane','OperatingFrequency',fc); % incident angle is 45 degrees azimuth, 10 degrees elevation incidentangle = [45;10]; % collect the incident waveform at the ULA receivedsig = step(hc,x,incidentangle);
If the Wavefront property value is 'Plane', phased.Collector collects each plane wave signal using the phase approximation of the time delays across collecting elements in the far field.
If the Wavefront property value is 'Unspecified', phased.Collector collects each channel independently.
For further details, see [1].