lumpedElement

Lumped element circuit to load antenna

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    Description

    The default lumpedElement object creates a lumped element object with empty impedance and frequency values.

    When you load an antenna using a lumped resistor, capacitor, or inductor, the electrical properties of the antenna change. These lumped elements are typically added to the antenna feed. You can use lumped elements to increase the bandwidth of the antenna without increasing the size of the antenna.

    Creation

    Syntax

    le = lumpedElement
    le = lumpedElement(PropertyName=Value)

    Description

    le = lumpedElement creates a default lumped element circuit.

    le = lumpedElement(PropertyName=Value) sets properties using one or more name-value arguments. PropertyName is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as PropertyName1=Value1,...,PropertyNameN=ValueN. Properties that you do not specify, retain their default values.

    For example, le = lumpedElement(Impedance=50) creates a lumped element circuit with an impedance of 50 ohms.

    example

    Properties

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    Complex impedance of circuit, specified as a real or complex vector of z-parameters in ohms.

    Example: Impedance=complex(75,30) specifies a complex impedance of 75+i30.

    Data Types: double
    Complex Number Support: Yes

    Frequency of operation of the lumped element, specified as a real vector in Hz. This operating frequency range must match with the operating frequency range of the antenna loaded by this lumped element.

    Example: Frequency=[10e6,20e6,30e6]

    Data Types: double

    Location of load, specified as by Cartesian coordinates. The default location of the lumped element is at the antenna feed.

    Example: Location=[0 0 0.5]

    Data Types: double

    Examples

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    Open Live Script

    Create a resistor with 50 Ohms of impedance. Any pure resistive load has a nonvariable impedance when the frequency changes.

    le = lumpedElement(Impedance=50);

    Create a dipole antenna. Calculate the impedance of the antenna without loading the antenna.

    d = dipole;
i1 = impedance(d,70e6)
    i1 = 
73.0370 - 0.4188i

    Load the antenna using a frequency-independent resistor. Calculate the impedance of the antenna.

    d.Load = le;
i1e1 = impedance(d,70e6)
    i1e1 = 
1.2304e+02 - 4.1883e-01i

    Change the frequency to 85 MHz and calculate the impedance of the antenna.

    ile2 = impedance(d,85e6)
    ile2 = 
2.2377e+02 + 1.1341e+02i
    Open Live Script

    Create a dipole antenna using one load at the antenna feed and one load at a location above the antenna feed.

    Create a dipole antenna.

    d = dipole;

    Create two lumped elements to load the dipole antenna.

    One lumped element of impedance, 50 Ohms, loads the antenna at the feed.

    l1 = lumpedElement(Impedance=complex(50,-20),Location="feed");

    The second lumped element of complex impedance, 50 + j*20 Ohms, loads the antenna at the top. Locate the load half distance from the feed.

    l2 = lumpedElement(Impedance=complex(50,-20),Location=[0 0 0.5]);

    Add the two loads to the dipole antenna.

     d.Load = [l1, l2];

    View the dipole antenna.

    show(d);

    Figure contains an axes object. The axes object with title dipole antenna element, xlabel x (m), ylabel y (m) contains 5 objects of type patch, surface. These objects represent PEC, feed, load.

    Version History

    Introduced in R2016b

    See Also

    Objects

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