Lumped element circuit to load antenna
creates a lumped
element circuit. The default value is an empty
le = lumpedElement
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.
Antenna Using Frequency Independent Load
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 = 72.9851 - 0.4727i
Load the antenna using a frequency-independent resistor. Calculate the impedance of the antenna.
d.Load = le; i1e1 = impedance(d,70e6)
i1e1 = 1.2299e+02 - 4.7272e-01i
Change the frequency to 85 MHz and calculate the impedance of the antenna.
ile2 = impedance(d,85e6)
ile2 = 2.2370e+02 + 1.1331e+02i
Antenna with Two Loads at Arbitrary Locations
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.
Specify optional pairs of arguments as
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.
Impedance — Complex impedance of circuit
real or complex vector of Z-parameters in ohms
Complex impedance of circuit, specified as a real or complex vector of z-parameters in ohms.
Impedance=complex(75,30) specifies a
complex impedance of
Frequency — Frequency of operation
real vector in Hz
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.
Location — Location of load
[0 0 0] (default) |
"feed" | Cartesian coordinates
Location of load, specified by Cartesian coordinates. The default location of the lumped element is at the antenna feed (x=0, y=0, z=0).
Location=[0 0 0.5]
le — Lumped element
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.
Introduced in R2016b