# beamwidth

Beamwidth of antenna

## Syntax

``beamwidth(object,frequency,azimuth,elevation)``
``bw = beamwidth(object,frequency,azimuth,elevation,dBdown)``
``````[bw,angles] = beamwidth(____)``````

## Description

````beamwidth(object,frequency,azimuth,elevation)` plots the beamwidth of the specified antenna or array at the specified frequency. The beamwidth is the angular separation at which the magnitude of the directivity pattern decreases by a certain value from the peak of the main beam. The directivity decreases in the direction specified by azimuth and elevation angles of the antenna. Note`beamwidth` plots only one beamwidth for symmetrical patterns.`beamwidth` might not interpret partial angle data well. ```

example

````bw = beamwidth(object,frequency,azimuth,elevation,dBdown)` returns the beamwidth of an antenna or array at a specified `dBdown` value from the peak of the main beam radiation pattern.```
``````[bw,angles] = beamwidth(____)``` returns the beamwidth and angles (points in a plane) using any input arguments from previous syntaxes.```

example

## Examples

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Plot the beamwidth for a dipole antenna at azimuth=0 and elevation=1:1:360 (x-z plane)

```d = dipole; beamwidth(d,70e6,0,1:1:360);```

Calculate the beamwidth of a helix antenna and the angles of the beamwidth. The antenna has an azimuth angle of 1:1:360 degrees, an elevation angle of 0 degrees on the X-Y plane, and a dB down value of 5 dB.

```hx = helix; [bw,angles] = beamwidth(hx,2e9,1:1:360,0,5)```
```bw = 141 ```
```angles = 1×2 146 287 ```

Create a `fractalGasket` antenna object.

`fg = fractalGasket(NumIterations=4, TiltAxis=[0 1 0], Tilt=90);`

Calculate beamwidth and angle of a `fractalGasket`.

`[bw,ang] = beamwidth(fg, 1.3e9, 0, 0:1:360)`
```bw = 2×1 34.0000 34.0000 ```
```ang = 2×2 25 59 121 155 ```

Plot beamwidth.

`beamwidth(fg, 1.3e9, 0, 0:1:360)`

Plot Second Beamwidth Solution

Get the `polarpattern` handle.

`P = polarpattern("gco"); `

Hide the beamwidth span and remove the cursor C1 and C2. All the cursors can also be removed using the function `removeCursors`.

```showSpan(P,0); removeCursors(P,1); removeCursors(P,2); ```

Add the cursors at other side of the plot and second beamwidth solution is displayed.

```addCursor(P,ang(2,:)); showSpan(P,1); ```

## Input Arguments

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Antenna, array, custom mesh, custom geometry, or custom antenna, specified as either of these:

Frequency used to calculate beamwidth, specified as a scalar in Hz.

Example: 70e6

Data Types: `double`

Azimuth angles used to calculate the beamwidth of the antenna or array, specified as a scalar or vector in degrees. If the elevation angle is specified as a vector, then the azimuth angle must be a scalar.

Example: 3

Data Types: `double`

Elevation angle used to calculate the beamwidth of the antenna or array, specified as a scalar or vector in degrees. If the azimuth angle is specified as a vector, then the elevation angle must be a scalar.

Example: 1:1:360

Data Types: `double`

Power point from peak of main beam of antenna or array, specified as a scalar in dB.

Example: 5

Data Types: `double`

## Output Arguments

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Beamwidth of antenna or array, returned as a scalar in degrees or a 2-by-1 vector in degrees.

Example: `141`

Data Types: `double`

Angular points encompassing the main beam on the azimuth or elevation pattern plot used to measure beamwidth, returned as a vector in degrees.

Example: `[146 287]`

Data Types: `double`

## Version History

Introduced in R2015a