# impedance

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)``

## Description

example

````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.```
````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. ```

## 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 × 0.2988 - 1.7742i 0.2988 - 1.7742i 0.3101 - 1.6906i 0.3101 - 1.6906i 0.3217 - 1.6088i 0.3217 - 1.6088i 0.3335 - 1.5287i 0.3335 - 1.5287i 0.3455 - 1.4501i 0.3455 - 1.4501i 0.3577 - 1.3728i 0.3577 - 1.3728i 0.3703 - 1.2967i 0.3703 - 1.2967i 0.3831 - 1.2216i 0.3831 - 1.2216i 0.3962 - 1.1476i 0.3962 - 1.1476i 0.4096 - 1.0743i 0.4096 - 1.0743i ⋮ ```

## Input Arguments

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Antenna for impedance analysis, specified as either an antenna object from the catalog or a custom antenna created using:

Example: `horn`

Array for impedance analysis, specified as an array object from the catalog or a custom array created using:

Example: `conformalArray`

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

Example: 50e6:1e6:100e6

Data Types: `double`

Antenna element number in array, specified as a scalar.

Example: 1

Data Types: `double`

## 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