bandwidth

Calculate and/or plot absolute bandwidth of antenna

Since R2024a

Syntax

[absBW, fRES, fL, fU, S] = bandwidth(object,frequency)

[absBW, fRES, fL, fU, S] = bandwidth(object,frequency,Name=Value)

[absBW,___] = bandwidth(object,frequency)

[absBW,___] = bandwidth(object,frequency,Name=Value)

bandwidth(object,frequency)

bandwidth(___,Name=Value)

Description

[absBW, fRES, fL, fU, S] = bandwidth(object,frequency) calculates and returns the absolute bandwidths absBW for each resonant frequency in fRES, and its lower (fL) and upper (fU) bounds for the specified antenna. absBW and fRES are empty if no bandwidth and/or resonant frequency is detected within the frequency sweep. And, they are vectors when there is more than one bandwidth. S is the vector of the entire S11 values spanning across the specified frequency band.

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

[absBW,___] = bandwidth(object,frequency) calculates and returns the absolute bandwidths absBW for each resonant frequency and other parameters.

[absBW,___] = bandwidth(object,frequency,Name=Value) uses additional options specified by one or more Name-Value Arguments to calculate and return the absolute bandwidths absBW for each resonant frequency and other parameters.

bandwidth(object,frequency) plots the S11 for the specified frequency range and marks the bandwidth on the plot.

bandwidth(___,Name=Value) uses additional options specified by one or more Name-Value Arguments to plot the S11 for the specified frequency range and mark the bandwidth on the plot.

Examples

Calculate and Plot Bandwidth of Dipole Antenna

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 = 6.6737e+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

object — Antenna to calculate bandwidth

antenna object | pcbStack object | customAntenna object | customAntennaMesh object | customAntennaGeometry object | infiniteArray object

Antenna to calculate bandwidth, specified as an antenna object.

Example: dipole

frequency — Frequency sweep in Hz

positive vector

Frequency sweep in Hz to calculate the bandwidth, specified as a positive vector.

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;

UseParallel — Flag to enable parallel pool

false (default) | true | 0 | 1

Flag to enable parallel pool, specified as a logical value. The default value is false. Set the flag 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

Data Types: logical

Z0 — Reference impedance in ohms to calculate S-parameters

50 (default) | positive real scalar

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

Example: 75

Data Types: double

Threshold — S11 threshold value in dB to calculate bandwidth

-10 (default) | numeric scalar

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

Example: -12

Data Types: double

PlotDataTips — Logical flag to enable or disable data tips

true (default) | false

Logical flag to enable or disable data tips, specified as either true to enable or false to disable. By default, the data tips are enabled.

Example: false

Data Types: logical

Output Arguments

absBW — Absolute bandwidth in Hz

positive scalar | positive vector

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

fRES — Resonant frequency in Hz

positive scalar | positive vector

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

fL — Lower frequency bound of bandwidth in Hz

positive scalar | positive vector

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

fU — Upper frequency bound of bandwidth in Hz

positive scalar | positive vector

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

S — S11 values in dB for entire frequency sweep

complex vector

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