# bandwidth

Calculate and plot absolute bandwidth of antenna or array

Since R2024a

## Description

bandwidth(object,frequency) marks the bandwidth on the S11 plot of the antenna or array in the specified frequency range.

bandwidth(object,frequency,Name=Value) marks the bandwidth on the S11 plot of the antenna or array in the specified frequency range using additional options specified by one or more Name-Value Arguments.

absBW = bandwidth(object,frequency) calculates and returns the absolute bandwidths absBW for the specified antenna or array at each resonant frequency within the specified frequency range.

absBW = bandwidth(object,frequency,Name=Value) calculates and returns the absolute bandwidths absBW of the specified antenna or array at each resonant frequency using additional options specified by one or more Name-Value Arguments.

[absBW,fRES,fL,fU,S] = bandwidth(object,frequency) calculates and returns the absolute bandwidths absBW at each resonant frequency in fRES, and the lower (fL) and upper (fU) bounds for the specified antenna or array. absBW and fRES are empty if no bandwidth or resonant frequency is detected within the specified frequency range. absBW and fRES are vectors when there are more than one bandwidths. S is a vector of all the S11 values across the specified frequency range.

example

[absBW,fRES,fL,fU,S] = bandwidth(object,frequency,Name=Value) calculates and returns the absolute bandwidths absBW at each resonant frequency in fRES, and the lower (fL) and upper (fU) bounds for the specified antenna or array using additional options specified by one or more Name-Value Arguments.

## Examples

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This example shows how to calculate and plot the bandwidth of a dipole antenna for different thresholds.

Create Dipole, Calculate and Plot Bandwidth with Default Threshold

Create a dipole operating at 75MHz. Calculate and plot the bandwidth of a dipole for a default threshold of -10dB over a frequency span 50MHz to 100MHz.

h = design(dipole,75e6);
absBW = bandwidth(h,50e6:1e6:100e6)
absBW =
6.6738e+06

bandwidth(h,50e6:1e6:100e6);

Calculate and Plot Bandwidth with Custom Threshold

Calculate and plot the bandwidth of the same dipole, using a -2dB threshold, over the same frequency span.

absBW = bandwidth(h,50e6:1e6:100e6,Threshold=-2)
absBW =
3.4303e+07

bandwidth(h,50e6:1e6:100e6,Threshold=-2);

## Input Arguments

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Antenna or array to calculate bandwidth, specified as one of the following options: an infiniteArray object, or a custom antenna created using either of these:

Example: dipole

Frequency range to calculate the bandwidth, specified as a positive vector in Hertz.

Example: [50e6:5e6:80e6]

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: Threshold=-2

Option to enable parallel pool, specified as a logical value. The default value is false. Set this option to true or 1 to enable the parallel pool. Use parallel pool to speedup the bandwidth calculations at multiple frequencies for computationally large antennas and arrays. To use this feature, you need a license to the Parallel Computing Toolbox™.

Example: UseParallel=true enables the parallel pool for bandwidth computation.

Data Types: logical

Reference impedance in ohms to calculate the S-parameters, specified as a positive real scalar. The default reference impedance is 50 ohms.

Example: Z0=75 sets the reference impedance to 75 ohms.

Data Types: double

S11 threshold value to calculate the bandwidth, specified as numeric scalar in dB.

Example: Threshold=-12 sets the threshold to -12 dB.

Data Types: double

Option to enable or disable the data tips, specified as a logical true to enable or logical false to disable the data tips. By default, the data tips are enabled.

Example: Specifying PlotDataTips=false disables the data tips on the plot.

Data Types: logical

## Output Arguments

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Absolute bandwidth in Hz of the specified antenna, returned as either positive scalar value for a single resonance or a positive vector for multiple resonances within the specified frequency sweep.

Example: 30e6

Resonant frequency in Hz of the specified antenna, returned as either positive scalar value for a single resonance or a positive vector for multiple resonances within the specified frequency sweep.

Example: 6.67e9

Data Types: double

Lower frequency bound of bandwidth in Hz, returned as scalar for a single resonance or a vector for multiple resonances within the specified frequency sweep.

Example: 6.64e9

Data Types: double

Upper frequency bound of bandwidth in Hz, returned as scalar for a single resonance or a vector for multiple resonances within the specified frequency sweep.

Example: 6.7e9

Data Types: double

S11 values in dB for the entire frequency sweep, returned as a complex vector.

Data Types: double
Complex Number Support: Yes

## Version History

Introduced in R2024a