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phased.ArrayGain System object

Sensor array gain

Description

The ArrayGain object calculates the array gain for a sensor array. The array gain is defined as the signal to noise ratio (SNR) improvement between the array output and the individual channel input, assuming the noise is spatially white. It is related to the array response but is not the same.

To compute the SNR gain of the antenna for specified directions:

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

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

Note

Starting in R2016b, instead of using the step method to perform the operation defined by the System object™, you can call the object with arguments, as if it were a function. For example, y = step(obj,x) and y = obj(x) perform equivalent operations.

Construction

H = phased.ArrayGain creates an array gain System object, H. This object calculates the array gain of a 2-element uniform linear array for specified directions.

H = phased.ArrayGain(Name,Value) creates and array-gain object, H, with the 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

Sensor array

Sensor array specified as an array System object belonging to the phased package. A sensor 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

Methods

stepCalculate array gain of sensor array
Common to All System Objects
clone

Create System object with same property values

getNumInputs

Expected number of inputs to a System object

getNumOutputs

Expected number of outputs of a System object

isLocked

Check locked states of a System object (logical)

release

Allow System object property value changes

Examples

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Calculate the array gain for a 4-element uniform linear array (ULA) in the direction 30° azimuth and 20° elevation. The array operating frequency is 300 MHz.

fc = 300e6;
array = phased.ULA(4);
gain = phased.ArrayGain('SensorArray',array);
g = gain(fc,[30;20])
g = -17.1783

Definitions

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References

[1] Guerci, J. R. Space-Time Adaptive Processing for Radar. Boston: Artech House, 2003.

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

Extended Capabilities

Introduced in R2012a

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