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lumpedElement

Lumped element circuit to load antenna

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Syntax

le = lumpedElement
le = lumpedElement(Name,Value)

Description

le = lumpedElement creates a lumped element circuit. The default value is an empty lumpedElement object.

When you load an antenna using a lumped resistor, capacitor, or inductor, the electrical properties of the antennas changes. 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.

example

le = lumpedElement(Name,Value) returns the lumped element circuit based on the properties specified by one or more Name,Value pair arguments.

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 = 73.2580 - 0.6797i

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

d.Load = le;
i1e1 = impedance(d,70e6)
i1e1 = 1.2326e+02 - 6.7973e-01i

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

ile2 = impedance(d,85e6)
ile2 = 2.3009e+02 + 1.1005e+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 contains 5 objects of type patch, surface. These objects represent PEC, feed, load.

Input Arguments
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Name-Value Arguments
Specify optional pairs of arguments as
      Name1=Value1,...,NameN=ValueN, where Name is
      the argument name and Value is the corresponding value.
      Name-value arguments must appear after other arguments, but the order of the
      pairs does not matter.
    

      Before R2021a, use commas to separate each name and value, and enclose 
      Name in quotes.
    
Example: 'Frequency',2e9


Complex impedance of circuit, specified as the comma-separated
pair consisting of 'Impedance' and 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


Frequency of operation, specified as the comma-separated pair
consisting of 'Frequency' and a real vector in
Hz.


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


Data Types: double


Location of load, specified as the comma-separated pair consisting of
                                'Location' and Cartesian coordinates.


Example: 'Location',[0 0 0.5]


Data Types: double
Output Arguments
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Lumped element, returned as a lumpedElement object.
The real part of the complex number indicates the resistance. The
imaginary part of the complex number indicates the reactance.


Version History
Introduced in R2016b
See Also