impedance

Calculate and plot input impedance of antenna or scan impedance of array

Syntax

impedance(antenna,frequency)

z = impedance(antenna,frequency)

impedance(array,frequency,elementnumber)

z = impedance(array,frequency,elementnumber)

z = impedance(___,UseParallel = true)

Description

impedance(antenna,frequency) calculates the input impedance of an antenna and plots the resistance and reactance over a specified frequency.

z = impedance(antenna,frequency) returns the impedance of the antenna over a specified frequency.

impedance(array,frequency,elementnumber) calculates and plots the scan impedance of a specified antenna element in an array.

z = impedance(array,frequency,elementnumber) returns the scan impedance of a specified antenna element in an array.

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

Examples

Calculate and Plot Impedance of Antenna

Calculate and plot the impedance of a planar dipole antenna over a frequency range of 50MHz - 100MHz.

h = dipole;
impedance (h,50e6:1e6:100e6);

Calculate Scan Impedance of Array

Calculate scan impedance of default linear array over a frequency range of 50MHz to 100MHz.

h = linearArray;
z = impedance(h,50e6:1e6:100e6)

z = 51×2 complex
102 ×

   0.2993 - 1.7755i   0.2993 - 1.7755i
   0.3106 - 1.6918i   0.3106 - 1.6918i
   0.3222 - 1.6099i   0.3222 - 1.6099i
   0.3340 - 1.5297i   0.3340 - 1.5297i
   0.3460 - 1.4509i   0.3460 - 1.4509i
   0.3582 - 1.3735i   0.3582 - 1.3735i
   0.3708 - 1.2973i   0.3708 - 1.2973i
   0.3836 - 1.2222i   0.3836 - 1.2222i
   0.3967 - 1.1481i   0.3967 - 1.1481i
   0.4101 - 1.0747i   0.4101 - 1.0747i
      ⋮

Input Arguments

antenna — Antenna for impedance analysis

antenna object | customAntennaMesh object | customAntennaGeometry object | customAntenna object | customAntennaStl object | pcbStack object | installedAntenna object

Antenna for impedance analysis, specified as one of the following options:

• Antenna object from the antenna catalog.

• customAntennaMesh object.

• customAntennaGeometry object.

• customAntenna object.

• customAntennaStl object.

• pcbStack object.

• installedAntenna object.

Example: horn

array — Array for impedance analysis

array object | customArrayMesh object | customArrayGeometry object

Array for impedance analysis, specified as one of the following option:

• Array object from the array catalog.

• customArrayMesh object.

• customArrayGeometry object.

Example: conformalArray

frequency — Frequency to calculate impedance

positive scalar | positive vector

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

Example: 50e6:1e6:100e6

Data Types: double

elementnumber — Antenna element number in array

positive integer scalar

Antenna element number in array, specified as a positive integer scalar.

Example: 1

Data Types: double

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 impedance calculations at multiple frequencies for computationally large antennas and arrays.

Example: UseParallel=true

Data Types: logical

Output Arguments

z — Input impedance of antenna or scan impedance of array

complex number in ohms

Input impedance of antenna or scan impedance of array, returned as a complex number in ohms. The real part of the complex number indicates the resistance. The imaginary part of the complex number indicates the reactance.

Note

Antenna Toolbox™ caches the impedance values while running for the first time so that the subsequent runs are faster.

Version History

Introduced in R2015a