phased.ArrayResponse System object

Package: phased

Sensor array response

Description

The ArrayResponse object calculates the complex-valued response of a sensor array.

To compute the response of the array for specified directions:

  1. Define and set up your array response calculator. See Construction.

  2. Call step to estimate the response according to the properties of phased.ArrayResponse. The behavior of step is specific to each object in the toolbox.

Construction

H = phased.ArrayResponse creates an array response System object™, H. This object calculates the response of a sensor array for the specified directions. By default, a 2-element uniform linear array (ULA) is used.

H = phased.ArrayResponse(Name,Value) creates object, H, with each specified property Name set to the specified Value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

Properties

SensorArray

Handle to sensor array used to calculate response

Specify the sensor array as a handle. The sensor array must be an array object in the phased package. The array can contain subarrays.

Default: phased.ULA with default property values

PropagationSpeed

Signal propagation speed

Specify the propagation speed of the signal, in meters per second, as a positive scalar.

Default: Speed of light

WeightsInputPort

Add input to specify weights

To specify weights, set this property to true and use the corresponding input argument when you invoke step. If you do not want to specify weights, set this property to false.

Default: false

EnablePolarization

Enable polarization simulation

Set this property to true to let the array response simulate polarization. Set this property to false to ignore polarization. This property applies only when the array specified in the SensorArray property is capable of simulating polarization.

Default: false

Methods

cloneCreate array response object with same property values
getNumInputsNumber of expected inputs to step method
getNumOutputsNumber of outputs from step method
isLockedLocked status for input attributes and nontunable properties
releaseAllow property value and input characteristics changes
stepCalculate array response of sensor array

Plot Array Response

Calculate array response for a 4-element uniform linear array (ULA) in the direction of 30 degrees azimuth and 20 degrees elevation. Assume the array's operating frequency is 300 MHz.

Construct ULA and ArrayResponse System objects

ha = phased.ULA(4);
har = phased.ArrayResponse('SensorArray',ha);
resp = step(har,3e8,[30;20]);

Plot the array response in dB

By default, the plot has a normalized power and is taken as an azimuth cut at 0 degrees elevation.

plotResponse(ha,3e8,physconst('LightSpeed'));

References

[1] Van Trees, H. Optimum Array Processing. New York: Wiley-Interscience, 2002.

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