metamaterial design in HFSS
I would like to know do i have change Cooper properties (permittivity) and ferrite (permeability)?
Or they have resonant mode themselves?
Hi Mamase,
You can artificially define a metamaterial by applying the reported relative dielectric permittivity and magnetic permeability to a material used in your design.
On the other hand, you can simulate a metamaterial resonator (e.g. Spiral o SRR) in a periodic unit cell, and try to retrieve its effective material properties from the S-parameters.
Regards,
Pere
Thank you very much
i have one more question,What is the formula for obtaining the structural parameters such as permittivity and permeability I use?
Hi,
If you have a metamaterial resonator inside a periodic unit cell, you can easily retrieve the effective parameters (eps and mu) from the s-parameters, by applying one of this methods:
-Nicholson-Ross-Weir (NRW), explained by Ziolkowski here: "Design, fabrication, and testing of double negative metamaterials" TAP 2003.
-Li, "Determination of the effective constitutive parameters of bianisotropic metamaterials from reflection and transmission coefficients" PRE 2009. Article
Regards,
Pere
thanks, but I working on "how to make meta-materials by using ferrite and an array of wiers in gigahertz interval of frequency" by using the HFSS program.
As it is known ferrite cause negative permibility and an array of wiers cause ( in some situations) negative epsilon.
I wanted to know that for using the ferrite in HFSS is it necessary to insert the behavior of the ferrite from the menu of edit material and set frequency dependence? or after applying a magnetic field to ferrite , the program creates the suitable resonance behavior?( for example in gigahertz interval)
I will be waiting for your answers
Sincerely yours
I wrote this code
Is that right?
clc
% extracted values of frequency %
f=[30.0 , 30.625, 31.25, 31.875,32.500,33.125,33.750,34.375,35.000,35.625,3 6.2500,36.8750,37.5000,38.1250,38.750,39.3750,40.0 000,40.6250,41.2500,41.8750,42.5000,43.12500,43.75 000,44.37500,45.00000,45.6250,46.2500,46.8750,47.5 000,48.1250,48.7500,49.3750,50.0000]
% s11 parameter %
s11=[-1.56 ,-1.80 ,-2.05,-2.33,-2.6504,-3.0252,-3.4710,-4.0084,-4.6659,-5.4769,-6.4890,-7.7728,-9.434,-11.6765,-14.7990,-19.919,-33.7676,-24.888,-17.720,-14.089,-11.767,-10.1313,-8.92165,-8.00691,-7.3044,-6.766008,-6.3570,-6.05145,-5.83227,-5.6948,-5.6225,-5.6197,-5.6727]
%extracted s21 parameter from simulation%
s21=[-5.19,-4.70,-4.25,-3.82,-3.411,-3.003,-2.601,-2.207,-1.822,-1.454,-1.110,-0.8003,-0.5318,-0.3126,-0.1526,-0.0508,-0.0078,-0.0208,-0.08314,-0.17887,-0.30498,-0.44897,-0.60147,-0.75405,-0.8998,-1.0334,-1.1489,-1.2454,-1.3220,-1.3707,-1.3972,-1.3981,-1.3782]
% formula from IEEE paper %
n=(acos((1./(2.*s21)).*(1-(s11).^2-(s21).^2)))./1.6; % Index %
z=sqrt(((1+s11).^2)-(s21).^2)./(((1-s11).^2)-(s21).^2); % Impedence %
plot(f, real(n), 'blue', f, imag(n), 'r');
title('index');
how i can draw phase or magnitude(Separately) of s parameter in HFSS?
Hi,
There are two issues in your code:
- Number of frequency points is 37, whereas the number of s-parameters points is 33. So the code does not work as it; I just used f=linspace(30,50,33) instead.
- Your s-parameters are in dB, but you need real-imaginary parts to compute the effective parameters. You can plot the real and imaginary parts of s11 or s21 in HFSS, then you export the results to a file, and then in Matlab, you build the complex s-parameters as s11="real(s11)"+j*"imag(s11)", where "real(s11)" or "imag(s11)" refer to the data columns in the results data file (from HFSS).
In case of persistent doubts, send me a private message.
Regards,
Pere
hi
why with Increasing the size of the vacuum chamber my Results are changed?
(the size of the vacuum chamber id more than 10*lambda)