How to use lumpedElement with a non-constant impedance (loading with capacitor)

The Matlab Reference describes lumpedElement like this :

"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. le = lumpedElement(Name,Value) returns the lumped element circuit based on the properties specified by one or more Name,Value pair arguments. lumpedElement 5-1"

But nowhere have I been able to find any description how actually to add a "simulated" capacitor load so having a non-constant impedance with ftequency.

I expect it is a simple question of knowing the correct name, but can not find any description anywhere.

Please help !!

Answer 1

[Shashank Kulkarni]

lumpedElement has a property called Impedance and frequency. Both of these values can be vectors to describe a frequency dependent impedance. I hope this answers the question.

[Gigi]

Sounds logical, but it produces error:

>> f1=linspace(300e6,330e6, 20);

>> le=lumpedElement.empty;

>> for i = [1:1:20]

le(i)=lumpedElement('Impedance',complex(6.6,a(i)),'Frequency',f1(i));

end

>> bow=bowtieRounded(Length=0.08,Load=le);

>> bow.impedance(f1);

>> bow.vswr(f1,7.5);

Error using em.EmStructures/loadingedge

Interpolated/Extrapolated value of load impedance is NaN

Error in em.EmStructures/momsolver

Error in em.EmStructures/analyze

Error in em.PortAnalysis/impedance (line 189)

status = analyze(obj,freq);

Error in em.PortAnalysis/vswr (line 83)

Z = impedance(obj,freq);