# pattern

Plot array directivity and patterns

## Syntax

## Description

`pattern(___,`

plots the
array pattern with additional options specified by one or more `Name,Value`

)`Name,Value`

pair arguments.

`[`

returns the array pattern in `PAT`

,`AZ_ANG`

,`EL_ANG`

] = pattern(___)`PAT`

. The `AZ_ANG`

output
contains the coordinate values corresponding to the rows of `PAT`

. The
`EL_ANG`

output contains the coordinate values corresponding to the columns
of `PAT`

. If the `'CoordinateSystem'`

parameter is set to
`'uv'`

, then `AZ_ANG`

contains the *U*
coordinates of the pattern and `EL_ANG`

contains the *V*
coordinates of the pattern. Otherwise, they are in angular units in degrees.
*UV* units are dimensionless.

## Examples

### Plot Response of NR Rectangular Panel Array

Construct a 5G antenna array where the grid is 2-by-2 and each panel is a 4-by-4 array. Each antenna element consists of two short-dipole antennas with different dipole axis directions. The antenna elements are spaced 1/2 wavelength apart and the panels are spaced 3 wavelengths apart. Plot the response pattern of the array assuming an operating frequency of 6 GHz.

c = physconst('LightSpeed'); fc = 6e9; lambda = c/fc; antenna1 = phased.ShortDipoleAntennaElement('AxisDirection','Z'); antenna2 = phased.ShortDipoleAntennaElement('AxisDirection','X'); array = phased.NRRectangularPanelArray('ElementSet', ... {antenna1, antenna2},'Size',[4, 4, 2, 2],'Spacing', ... [0.5*lambda, 0.5*lambda,3*lambda, 3*lambda]); pattern(array,fc,'ShowArray',true)

Use the `Orientation`

property of `pattern`

to change the orientation $$8{0}^{\circ}$$ along the *x*-axis, $$3{0}^{\circ}$$ along the *y*-axis and $$6{0}^{\circ}$$ along the *z*-axis.

pattern(array,fc,'Orientation',[80;30;60],'ShowArray',true)

Disable the display of local coordinates and the colorbar.

pattern(array,fc,'ShowLocalCoordinate',false,'ShowColorBar',false)

## Input Arguments

`array`

— Phased array

Phased Array System Toolbox™
System object™

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

`FREQ`

— Frequency for computing directivity and patterns

positive scalar | 1-by-*L* real-valued row vector

Frequencies for computing directivity and patterns, specified
as a positive scalar or 1-by-*L* real-valued row
vector. Frequency units are in hertz.

For an antenna, microphone, or sonar hydrophone or projector element,

`FREQ`

must lie within the range of values specified by the`FrequencyRange`

or`FrequencyVector`

property of the element. Otherwise, the element produces no response and the directivity is returned as`–Inf`

. Most elements use the`FrequencyRange`

property except for`phased.CustomAntennaElement`

and`phased.CustomMicrophoneElement`

, which use the`FrequencyVector`

property.For an array of elements,

`FREQ`

must lie within the frequency range of the elements that make up the array. Otherwise, the array produces no response and the directivity is returned as`–Inf`

.

**Example: **`[1e8 2e6]`

**Data Types: **`double`

`AZ`

— Azimuth angles

`[-180:180]`

(default) | 1-by-*N* real-valued row vector

Azimuth angles for computing directivity and pattern, specified as a 1-by-*N*
real-valued row vector where *N* is the number of azimuth angles. Angle
units are in degrees. Azimuth angles must lie between –180° and 180°.

The azimuth angle is the angle between the *x*-axis
and the projection of the direction vector onto the *xy* plane.
When measured from the *x*-axis toward the *y*-axis,
this angle is positive.

**Example: **`[-45:2:45]`

**Data Types: **`double`

`EL`

— Elevation angles

`[-90:90]`

(default) | 1-by-*M* real-valued row vector

Elevation angles for computing directivity and pattern, specified as a
1-by-*M* real-valued row vector where *M* is the
number of desired elevation directions. Angle units are in degrees. The elevation angle
must lie between –90° and 90°.

The elevation angle is the angle between the direction vector and *xy*-plane.
The elevation angle is positive when measured towards the
*z*-axis.

**Example: **`[-75:1:70]`

**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.

*
Before R2021a, use commas to separate each name and value, and enclose*
`Name`

*in quotes.*

**Example: **`CoordinateSystem,'polar',Type,'directivity'`

`CoordinateSystem`

— Plotting coordinate system

`'polar'`

(default) | `'rectangular'`

| `'uv'`

Plotting coordinate system of the pattern, specified as the
comma-separated pair consisting of `'CoordinateSystem'`

and
one of `'polar'`

, `'rectangular'`

,
or `'uv'`

. When `'CoordinateSystem'`

is
set to `'polar'`

or `'rectangular'`

,
the `AZ`

and `EL`

arguments
specify the pattern azimuth and elevation, respectively. `AZ`

values
must lie between –180° and 180°. `EL`

values
must lie between –90° and 90°. If `'CoordinateSystem'`

is
set to `'uv'`

, `AZ`

and `EL`

then
specify *U* and *V* coordinates,
respectively. `AZ`

and `EL`

must
lie between -1 and 1.

**Example: **`'uv'`

**Data Types: **`char`

`Type`

— Displayed pattern type

`'directivity'`

(default) | `'efield'`

| `'power'`

| `'powerdb'`

Displayed pattern type, specified as the comma-separated pair
consisting of `'Type'`

and one of

`'directivity'`

— directivity pattern measured in dBi.`'efield'`

— field pattern of the sensor or array. For acoustic sensors, the displayed pattern is for the scalar sound field.`'power'`

— power pattern of the sensor or array defined as the square of the field pattern.`'powerdb'`

— power pattern converted to dB.

**Example: **`'powerdb'`

**Data Types: **`char`

`Orientation`

— Array orientation

`[0;0;0]`

. (default) | 3-by-1 real-valued column vector

Array orientation, specified as a 3-by-1 real-valued column vector containing the
rotation angles with respect to the *x*-, *y*-, and
*z*-axes of the local coordinate system, respectively.

`Normalize`

— Display normalize pattern

`true`

(default) | `false`

Display normalized pattern, specified as the comma-separated pair consisting of
`'Normalize`

' and a Boolean. Set this parameter to
`true`

to display a normalized pattern. This parameter does not
apply when you set `'Type'`

to `'directivity'`

.
Directivity patterns are already normalized.

**Data Types: **`logical`

`ShowArray`

— View array geometry

`false`

(default) | `true`

View the array geometry along with the 3D radiation pattern, specified as
`false`

or `true`

.

**Data Types: **`logical`

`ShowLocalCoordinates`

— Show local coordinate axes

`true`

(default) | `false`

Show the local coordinate axes, specified as `true`

or `false`

.

**Data Types: **`logical`

`ShowColorbar`

— Show colorbar

`true`

(default) | `false`

Show the colorbar, specified as `true`

or `false`

.

**Data Types: **`logical`

`Parent`

— Handle to axis

scalar

Handle to the axes along which the array geometry is displayed specified as a scalar.

`PlotStyle`

— Plotting style

`'overlay'`

(default) | `'waterfall'`

`Polarization`

— Polarization type

`'combined'`

(default) | `'H'`

| `'V'`

Polarization type, specified as the comma-separated pair consisting of
`'Polarization'`

and either `'combined'`

,
`'H'`

, or `'V'`

. If `Polarization`

is
`'combined'`

, the horizontal and vertical polarization patterns are
combined. If `Polarization`

is `'H'`

, only the horizontal
polarization is displayed. If `Polarization`

is `'V'`

,
only the vertical polarization is displayed.

#### Dependencies

To enable this property, set the `array`

argument to an array that
supports polarization and then set the `'Type'`

name-value pair to
`'efield'`

, `'power'`

, or
`'powerdb'`

.

**Data Types: **`char`

| `string`

`PropagationSpeed`

— Signal propagation speed

speed of light (default) | positive scalar

Signal propagation speed, specified as the comma-separated pair
consisting of `'PropagationSpeed'`

and a positive
scalar in meters per second.

**Example: **`'PropagationSpeed',physconst('LightSpeed')`

**Data Types: **`double`

`Weights`

— Array weights

1 (default) | *N*-by-1 complex-valued column vector | *N*-by-*L* complex-valued
matrix

Array weights, specified as the comma-separated pair consisting
of `'Weights`

' and an *N*-by-1 complex-valued
column vector or *N*-by-*L* complex-valued
matrix. Array weights are applied to the elements of the array to
produce array steering, tapering, or both. The dimension *N* is
the number of elements in the array. The dimension *L* is
the number of frequencies specified by `FREQ`

.

Weights Dimension | FREQ Dimension | Purpose |
---|---|---|

N-by-1 complex-valued column vector | Scalar or 1-by-L row vector | Applies a set of weights for the single frequency or for all L frequencies. |

N-by-L complex-valued
matrix | 1-by-L row vector | Applies each of the L columns of `'Weights'` for
the corresponding frequency in `FREQ` . |

**Note**

Use complex weights to steer the array response toward different
directions. You can create weights using the `phased.SteeringVector`

System object or
you can compute your own weights. In general, you apply Hermitian
conjugation before using weights in any Phased Array System Toolbox function
or System object such as `phased.Radiator`

or `phased.Collector`

. However, for the `directivity`

, `pattern`

, `patternAzimuth`

,
and `patternElevation`

methods of any array System object use
the steering vector without conjugation.

**Example: **`'Weights',ones(N,M)`

**Data Types: **`double`

**Complex Number Support: **Yes

## Output Arguments

`PAT`

— array pattern

*N*-by-*M* real-valued matrix

## More About

### Directivity

Directivity describes the directionality of the radiation pattern of a sensor element or array of sensor elements.

Higher directivity is desired when you want to transmit more radiation in a specific direction. Directivity is the ratio of the transmitted radiant intensity in a specified direction to the radiant intensity transmitted by an isotropic radiator with the same total transmitted power

$$D=4\pi \frac{{U}_{\text{rad}}\left(\theta ,\phi \right)}{{P}_{\text{total}}}$$

where
*U*_{rad}*(θ,φ)* is the radiant
intensity of a transmitter in the direction *(θ,φ)* and
*P*_{total} is the total power transmitted by an
isotropic radiator. For a receiving element or array, directivity measures the sensitivity
toward radiation arriving from a specific direction. The principle of reciprocity shows that
the directivity of an element or array used for reception equals the directivity of the same
element or array used for transmission. When converted to decibels, the directivity is
denoted as *dBi*. For information on directivity, read the notes on Element Directivity and Array Directivity.

### Azimuth and Elevation Angles

Define the azimuth and elevation conventions used in the toolbox.

The *azimuth angle* of a vector is the angle between the
*x*-axis and its orthogonal projection onto the
*xy*-plane. The angle is positive when going from the
*x*-axis toward the *y*-axis. Azimuth angles lie between
–180° and 180° degrees, inclusive. The *elevation angle* is the angle
between the vector and its orthogonal projection onto the *xy*-plane. The
angle is positive when going toward the positive *z*-axis from the
*xy*-plane. Elevation angles lie between –90° and 90° degrees, inclusive.

## Version History

**Introduced in R2021a**

## Open Example

You have a modified version of this example. Do you want to open this example with your edits?

## MATLAB Command

You clicked a link that corresponds to this MATLAB command:

Run the command by entering it in the MATLAB Command Window. Web browsers do not support MATLAB commands.

# Select a Web Site

Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .

You can also select a web site from the following list:

## How to Get Best Site Performance

Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.

### Americas

- América Latina (Español)
- Canada (English)
- United States (English)

### Europe

- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)

- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)