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impedance

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

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    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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    Open Live Script

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

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

    Figure contains an axes object. The axes object with title Impedance, xlabel Frequency (MHz), ylabel Impedance (ohms) contains 2 objects of type line. These objects represent Resistance, Reactance.

    Open Live Script

    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

    See Also

    Functions

    Topics