vswr

Calculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Syntax

vswr(object,frequency,z0)

vswRatio = vswr(object,frequency,z0)

vswRatio = vswr(___,UseParallel = true)

Description

vswr(object,frequency,z0) calculates and plots the VSWR of an antenna or an array element, over specified frequency range, and a reference impedance of z0 ohms.

vswRatio = vswr(object,frequency,z0) calculates and returns the VSWR of an antenna or array element, over specified frequency range, and a reference impedance of z0 ohms.

vswRatio = vswr(___,UseParallel = true) uses the Parallel Computing Toolbox™ to perform VSWR calculations for each frequency in parallel. To use this feature, you need a license to the Parallel Computing Toolbox.

Examples

Plot VSWR of Antenna

Plot vswr (voltage standing wave ratio) of a circular loop antenna.

h = loopCircular;
vswr(h,50e6:1e6:100e6,50)

Calculate VSWR of Antenna

Calculate vswr (voltage standing wave ratio) of a helix antenna.

h = helix;
hvswr = vswr(h,2e9:1e9:4e9,50)

hvswr = 1×3

    3.6047    6.7230    3.3524

Input Arguments

object — Antenna or array to calculate VSWR

antenna object | array object | custom antenna | custom array | pcbStack object | installedAntenna object

Antenna or array to calculate the VSWR, specified as one of the following options:

• Antenna object from the antenna catalog.

• Array object from the array catalog.

• Custom 2-D mesh or geometry object.

• Custom 2-D and 3-D antenna object.

• pcbStack object.

• installedAntenna object.

Example: dipole

frequency — Frequency to calculate VSWR

positive scalar | positive vector

Frequency to calculate the VSWR, specified as a scalar for a single frequency or a vector for a frequency range in Hertz.

Example: 75e6

Example: 50e6:1e6:100e6

Data Types: double

z0 — Reference impedance

50 (default) | scalar

Reference impedance, specified as a scalar in ohms.

UseParallel — Option to enable parallel pool

false or 0 (default) | true or 1

Option 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 VSWR calculations at multiple frequencies for computationally large antennas and arrays.

Example: UseParallel=true

Data Types: logical

Output Arguments

vswRatio — Voltage standing wave ratio

scalar | vector

Voltage standing wave ratio, returned as a scalar in dB for a single analysis frequency and a vector in dB for analysis over a frequency range.

Version History

Introduced in R2015a