perturbedPattern

Display pattern of perturbed array

Since R2022a

Syntax

pmc = perturbedPattern(array,freq)

pmc = perturbedPattern(array,freq,az)

pmc = perturbedPattern(array,freq,az,el)

pmc = perturbedPattern(___,Name=Value)

[pmc,pnm,mpmc,varpmc] = perturbedPattern(array,___)

perturbedPattern(array,___)

Description

pmc = perturbedPattern(array,freq) returns a set of perturbed azimuth array patterns pmc for an array generated from 100 Monte-Carlo runs. freq specifies the operating frequency at which the pattern is computed.

pmc = perturbedPattern(array,freq,az) also specifies the azimuth angles az used for computing the perturbed patterns.

pmc = perturbedPattern(array,freq,az,el) also specifies the elevation angles el used for computing the perturbed patterns.

pmc = perturbedPattern(___,Name=Value) also sets the specified parameter Name to the specified Value. You can specify additional name-value pair arguments in any order as (Name1=Value1,...,NameN=ValueN). For example, NumTrials = 10000.

[pmc,pnm,mpmc,varpmc] = perturbedPattern(array,___) also returns the nominal array response pattern pnm, the mean array response pattern mpmc, and the variance of the array response pattern varpmc.

perturbedPattern(array,___) plots all perturbed patterns for all Monte-Carlo runs and overlays them with both the nominal array response pattern and the mean perturbed array response pattern.

Examples

Compute Power Pattern of Perturbed ULA for All Azimuth Angles

Create an 11-element Uniform Linear Array. The array operates at 300 MHz and its elements are spaced one-half wavelength apart. Perturb the element positions by 1/20th of a wavelength. Use the default value of 100 Monte Carlo runs. Compute the pattern for the first simulation at all azimuth angles. Set the random number generator seed for reproducibility.

freq = 300.0e6;
lambda = physconst('LightSpeed')/freq;
d = lambda/2;
array = phased.ULA(11,ElementSpacing=d/2);
rng(10007)
perturbations(array,'ElementPosition','Normal',0,lambda/20);
perturbations(array,'TaperMagnitude','Normal',0,0.1);
pmc = perturbedPattern(array,freq);

Plot the array pattern vs azimuth angle.

plot(mag2db(abs(pmc(:,1))))
ylabel('Array Response (dB)')
xlabel('Azimith Angle (deg)')
title('Array Response')
grid on
xticks([0:30:180])

Compute Power Pattern of Perturbed ULA for Span of Azimuth Angles

Create an 11-element uniform linear array (ULA). The array operates at 300 MHz and its elements are spaced one-half wavelength apart. Perturb the element positions by 1/20th of a wavelength. Use the default value of 100 Monte Carlo runs. Compute the pattern for the first simulation at azimuth angles from $-45$ to $+45$ degrees. Set the seed of the random number generator for reproducibilty.

freq = 300.0e6;
lambda = physconst('LightSpeed')/freq;
d = lambda/2;
array = phased.ULA(11,ElementSpacing = d/2);
rng(230081)
perturbations(array,'ElementPosition','Normal',0,lambda/20);
perturbations(array,'TaperMagnitude','Normal',0,0.1);

Display the array response pattern for the first Monte Carlo run.

azang = -45:45;
pmc = perturbedPattern(array,freq,azang);
plot(azang,mag2db(abs(pmc(:,1))))
title('Response Pattern')
xlabel('Azimuth Angle (deg)')
ylabel('Array Response (dB)')
xticks([-45:15:45])
grid on

Compute Power Pattern for Steered Array

Create an 11-element Uniform Linear Array. The array operates at 300 MHz and its elements are spaced one-half wavelength apart. Perturb the element positions by 1/20th of a wavelength. Run 200 Monte Carlo simulations and steer the array 30 degrees in azimuth.

freq = 300e6;
lambda = physconst('Lightspeed')/freq;
d = lambda/2;
array = phased.ULA(11,ElementSpacing=d/2);
pos = getElementPosition(array);
sv = steervec(pos,30);
perturbations(array,'ElementPosition','Normal',0,lambda/20);
perturbations(array,'TaperMagnitude','Normal',0,0.1);
azang = -90:90;
elang = 0;
perturbedPattern(array,freq,azang,elang,Weights=sv,NumTrials=200);

Input Arguments

array — Phased array

Phased Array System Toolbox™ System object™

Phased array, specified as a Phased Array System Toolbox System object.

freq — Frequency used to compute array patterns

positive scalar

Frequency used to compute array patterns, specified as a positive scalar. Units are in Hz.

Data Types: double

az — Azimuth angles

scalar | length-M real-valued vector

Azimuth angles for computing power pattern, specified as a scalar or length-M real-valued vector. Either az or el, must be a scalar. Units are in degrees.

Data Types: double

el — Elevation angles

scalar | length-M real-valued vector

Elevation angles for computing power pattern, specified as a scalar or length-N real-valued vector. Either az or el must be a scalar. Units are in degrees.

Data Types: double

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: pmc = perturbedPatter(array,NumTrials = 1000)

NumTrials — Number of Monte-Carlo trials

positive integer

Number of Monte-Carlo trials, specified as a positive integer.

Data Types: double

Parent — Axes on which the pattern is displayed

axes handle

Axes on which the pattern is displayed, specified as an axis handle..

Data Types: double

PropagationSpeed — Signal propagation speed

physconst('lightSpeed') (default) | positive scalar

Signal propagation speed, specified as a positive scalar. The default value is physconst('lightSpeed'). Units are in m/s.

Example: 300e6

Data Types: double

Weights — Element weights

length-P complex-valued vector

Element weights, specified as a length-P complex-valued vector. P is the number of elements belonging to the array specified in the array argument.

Example: ones(11,1)

Data Types: double
Complex Number Support: Yes

Output Arguments

pmc — Perturbed array pattern

length-Q vector

Perturbed array pattern, returned as an M-by-Q or N-by-Q complex-valued matrix. M is the number of angles in the az argument. N is the number of angles in the el argument. Either az or el must be a scalar.Q is the number of Monte-Carlo trials. Each trial generates a different pattern. Units are in degrees.

Data Types: double
Complex Number Support: Yes

pnm — Nominal array pattern

length-M real-valued vector | length-N real-valued vector

Nominal array pattern, returned as an M complex-valued vector or as an N-by-Q complex-valued vector. M is the number of angles in the az argument. N is the number of angles in the al argument. Either az or el must be a scalar. Units are in degrees.

Data Types: double

mpmc — Mean of array response pattern

length-N real-valued vector | length-N real-valued vector

Mean of array response pattern, returned as a length-M real-valued vector or as an length-N real-valued vector. M is the number of angles in the az argument. N is the number of angles in the al argument. Units are in degrees.

Data Types: double

varpmc — Variance of array response pattern

length-N real-valued vector | length-N real-valued vector

Variance of array response pattern, returned as a length-M real-valued vector or as an length-N real-valued vector. M is the number of angles in the az argument. N is the number of angles in the al argument. Units are in degrees.

Data Types: double

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2022a