**System object: **phased.PartitionedArray

**Package: **phased

Plot partitioned array directivity or pattern versus azimuth

`patternAzimuth(sArray,FREQ)`

patternAzimuth(sArray,FREQ,EL)

patternAzimuth(sArray,FREQ,EL,Name,Value)

PAT = patternAzimuth(___)

`patternAzimuth(`

plots
the 2-D array directivity pattern versus azimuth (in dBi) for the
array `sArray`

,`FREQ`

)`sArray`

at zero degrees elevation angle.
The argument `FREQ`

specifies the operating frequency.

`patternAzimuth(`

,
in addition, plots the 2-D array directivity pattern versus azimuth (in dBi) for the array
`sArray`

,`FREQ`

,`EL`

)`sArray`

at the elevation angle specified by `EL`

.
When `EL`

is a vector, multiple overlaid plots are created.

`patternAzimuth(`

plots the array pattern with additional options specified by one or
more `sArray`

,`FREQ`

,`EL`

,`Name,Value`

)`Name,Value`

pair arguments.

returns
the array pattern. `PAT`

= patternAzimuth(___)`PAT`

is a matrix whose entries
represent the pattern at corresponding sampling points specified by
the `'Azimuth'`

parameter and the `EL`

input
argument.

`sArray`

— Partitioned arraySystem object™

Partitioned array, specified as a `phased.PartitionedArray`

System
object.

**Example: **`sArray= phased.PartitionedArray;`

`FREQ`

— Frequency for computing directivity and patternpositive scalar

Frequency for computing directivity and pattern, specified as a positive scalar. Frequency units are in hertz.

For an antenna or microphone element,

`FREQ`

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

or the`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`

**Data Types: **`double`

`EL`

— Elevation angles1-by-

Elevation angles for computing sensor or array directivities and patterns, specified as a
1-by-*N* real-valued row vector. The quantity *N*
is the number of requested 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 the *xy* plane. When measured toward the *z*-axis,
this angle is positive.

**Example: **`[0,10,20]`

**Data Types: **`double`

Specify optional
comma-separated pairs of `Name,Value`

arguments. `Name`

is
the argument name and `Value`

is the corresponding value.
`Name`

must appear inside quotes. You can specify several name and value
pair arguments in any order as
`Name1,Value1,...,NameN,ValueN`

.

`'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`

`'PropagationSpeed'`

— Signal propagation speedspeed 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'`

— Subarray weightsSubarray weights, specified as the comma-separated pair consisting
of `'Weights'`

and an *M*-by-1 complex-valued
column vector. Subarray weights are applied to the subarrays of the
array to produce array steering, tapering, or both. The dimension *M* is
the number of subarrays in the array.

**Example: **`'Weights',ones(10,1)`

**Data Types: **`double`

**Complex Number Support: **Yes

`'SteerAngle'`

— Subarray steering angle`[0;0]`

(default) | scalar | 2-element column vectorSubarray steering angle, specified as the comma-separated pair
consisting of `'SteerAngle'`

and a scalar or a 2-by-1
column vector.

If `'SteerAngle'`

is a 2-by-1 column vector,
it has the form `[azimuth; elevation]`

. The azimuth
angle must be between –180° and 180°, inclusive.
The elevation angle must be between –90° and 90°,
inclusive.

If `'SteerAngle'`

is a scalar, it specifies
the azimuth angle only. In this case, the elevation angle is assumed
to be 0.

This option applies only when the `'SubarraySteering'`

property
of the System
object is set to `'Phase'`

or `'Time'`

.

**Example: **`'SteerAngle',[20;30]`

**Data Types: **`double`

`'ElementWeights'`

— Weights applied to elements within subarray`1`

(default) | complex-valued Subarray element weights, specified as complex-valued
*N _{SE}*-by-

If `ElementWeights`

is a complex-valued
*N _{SE}*-by-

If `ElementWeights`

is a 1-by-*N* cell array. Each
cell contains a complex-valued column vector of weights for the corresponding subarray.
The column vectors have lengths equal to the number of elements in the corresponding
subarray.

To enable this name-value pair, set the `SubarraySteering`

property of the array to `'Custom'`

.

**Data Types: **`double`

**Complex Number Support: **Yes

`'Azimuth'`

— Azimuth angles`[-180:180]`

(default) | 1-by-Azimuth angles, specified as the comma-separated pair consisting
of `'Azimuth'`

and a 1-by-*P* real-valued
row vector. Azimuth angles define where the array pattern is calculated.

**Example: **`'Azimuth',[-90:2:90]`

**Data Types: **`double`

`PAT`

— Array directivity or patternArray directivity or pattern, returned as an *L*-by-*N*
real-valued matrix. The dimension *L* is the number of azimuth values
determined by the `'Azimuth'`

name-value pair argument. The dimension
*N* is the number of elevation angles, as determined by the
`EL`

input argument.

Convert a 2-by-6 URA of isotropic antenna elements into a 1-by-3 partitioned array so that each subarray of the partitioned array is a 2-by-2 URA. Assume that the frequency response of the elements lies between 1 and 6 GHz. The elements are spaced one-half wavelength apart corresponding to the highest frequency of the element response. Plot the azimuth directivity. For partitioned arrays, weights are applied to the subarrays instead of the elements.

**Create partitioned array**

fmin = 1e9; fmax = 6e9; c = physconst('LightSpeed'); lam = c/fmax; sIso = phased.IsotropicAntennaElement(... 'FrequencyRange',[fmin,fmax],... 'BackBaffled',false); sURA = phased.URA('Element',sIso,'Size',[2,6],... 'ElementSpacing',[lam/2,lam/2]); subarraymap = [[1,1,1,1,0,0,0,0,0,0,0,0];... [0,0,0,0,1,1,1,1,0,0,0,0];... [0,0,0,0,0,0,0,0,1,1,1,1]]; sPA = phased.PartitionedArray('Array',sURA,... 'SubarraySelection',subarraymap);

**Plot azimuth directivity pattern**

Plot the response of the array at 5 GHz

fc = 5e9; wts = [0.862,1.23,0.862]'; patternAzimuth(sPA,fc,0,... 'Type','directivity',... 'PropagationSpeed',physconst('LightSpeed'),... 'Weights',wts)

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.

Computing directivity requires integrating the far-field transmitted radiant intensity over all directions in space to obtain the total transmitted power. There is a difference between how that integration is performed when Antenna Toolbox™ antennas are used in a phased array and when Phased Array System Toolbox™ antennas are used. When an array contains Antenna Toolbox antennas, the directivity computation is performed using a triangular mesh created from 500 regularly spaced points over a sphere. For Phased Array System Toolbox antennas, the integration uses a uniform rectangular mesh of points spaced 1° apart in azimuth and elevation over a sphere. There may be significant differences in computed directivity, especially for large arrays.

A modified version of this example exists on your system. Do you want to open this version instead?

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.

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: .

Select web siteYou can also select a web site from the following list:

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

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

- 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)