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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.```

example

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

example

````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

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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 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

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

Example: `horn`

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

Example: `conformalArray`

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`

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

Example: `1`

Data Types: `double`

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

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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