Science topic

# Metamaterials - Science topic

Metamaterials are artificial materials engineered to have properties that may not be found in nature.

Questions related to Metamaterials

I am working on lattice structures. I saw in some papers that they used nTopolgy software to achieve the structures' stiffness matrix. unfortunately, I do not have access to this software.

You may guide me from which software or what solution I can get this matrix.

I look forward to your kind reply.
Sincerely yours

Metasurfaces have been presenting themselves in recent years as promising materials for holography, control of intensity and phase of optical waves, among others; and, in various applications in optics, such as metalens, optical manipulation, 3D image, optical communications and others. What are the advantages (and disadvantages) of holographic metasurfaces in relation to other potential holographic recording medium, such as photorefractive crystals and other photosensitive materials (glasses and polymers)?

I have designed the equivalent circuit of a metamaterial absorber which consists of L, C. S parameter, I got from CST software. Now I want to find out the lumped parameter values. So kindly help me how to find out these parameters value using ADS circuit simulation software?

I am confused about calculating the absorbability of the metamaterial absorber in between the two formulas below.

A=1-R-T ...............(1)

A=1-R ...............(2)

A=Absorbability

R=Reflection

T=Transmission

calculate the absorbability by equation 1 is mostly published metamaterial absorber paper. But nowadays, other authors comment on these papers.

I also want to design a metamaterial absorber. But which is the formula I use to calculate the absorbability of metamaterial absorbers.

Hi,

I have designed a metamaterial structure in HFSS software. I am getting S11 below -10db for certain frequency range, but confused with real and imaginary plot of permitivity,permeability and refcractive index. I am sharing the image of structure and plots. Can anyone help me understand if this structure is behaving metamaterial or not.

Thanks in advance.

Please let me know how to draw a color plot of PHP propagation of nanomaterials using mathematical tools. Actually, I am unable to draw phonons propagation using COMSOL. Is it possible to find out the plot using Matlab or other tools?

I want to simulate the developed metamaterial in CST Studio. However, simulation in the Period Structures template does not give me any results. The main aim is to find the permittivity and permeability values from the simulation results. Can someone please tell me what kind of template is appropriate to use and what the settings are?

We want to simulate a metamaterial Antenna in HFSS.

Hi !!

During simulation of space coiling up acoustic metamaterial in comsol acoustic-solid structure frequency domain to retrieve the transmission coefficent ,how could we apply floquet boundary condition for a plane wave.

Can someone show me using some numbers or related simulation file ? for better illustration please see the attached file.

Thanks

Please see attachment, here two terms appeared in the inhomogeneous Helmholtz equation.
What is the use of these two terms for a propagating wave in a particular direction.

Imagine the long-term and almost periodical interaction of gravitation waves with existing distribution of atoms (mostly hydrogen) in deep space. Billions of years of interaction can form a repetitive structure of atoms in huge volume (in 3-Dimesions), with some statistical deviations which can be caused by irregularities of gravitation waves.

Can this repetitive structure (in absence of near source of gravitation) represent some properties of Metamaterials?

Hello.

I try to design metamaterials consisting of a split-ring resonator (SRR) to manipulate its polarization.

To estimate polarization control of the metamaterials for any given incident waves, Jones matrix needs to be obtained, which is a matrix related to input/output electric fields in X and Y axis.

Using HFSS, I designed a SRR where two Floquet ports are located at top and bottom of the SRR and master/slave boundaries surround the SRR.

After running the simulation, I can plot S-parameters for several combinations of ports and excitation modes (TE and TM modes).

But, I couldn't find the ratio of transmitted and incident electric fields in X and Y axis which is necessary to identify the polarization states.

Please, let me know how to simulate E-field transmission coefficient of metamaterials using HFSS.

which is efficient model to generate band gaps for acoustic meta materials

Hi all,

Looking at the wikipedia page for photonic crystals, there is a section that reads:

"One-dimensional photonic crystals can include layers of non-linear optical materials in which the non-linear behaviour is accentuated due to field enhancement at wavelengths near a so-called degenerate band edge. This field enhancement (in terms of intensity) can reach N^2 where

*N*is the total number of layers"Can anybody explain this effect? Is there a field enhancement if a 1D photonic crystal is made of two materials with arbitrary permittivities, eps1 and eps2?

Does the enhancement happen without the non-linear permittivity? All materials will exhibit some natural non-linearity, if you drive them hard enough, right?

Or is the magic due to something with this 'degenerate band edge'? Can someone expand on degenerate band edge?

Hi,

I am trying to plot the dispersion diagram for a transmission line metamaterial IFA antenna, consisting of a capacitor in series and an inductor in parallel to the antenna.

As far as I know, the dispersion diagram is the plot of frequency vs. phase of S

_{21}, as phase (theta) is beta*length.But how to plot the dispersion diagram of an antenna which has only one port?

Kindly help me!

With Regards,

Suhas D

I have a metamaterial absorber structure consisting of several metal-dielectric-metal layers, I have drawn the electric and magnetic field distribution between every two layers.

I want to get the value of the electric and magnetic fields, to calculate the amount of power entering each layer. Note that I am using the Lumerical program (FDTD).

Is there a code or a script for an E, H, and power calculation?

Thanks.

I plotted the field strengths of the metamaterial absorber layers, and these values are shown to me on the right of the figure. What do these values represent? If it represents the strength of the field, isn't this value too large?

The values that are shown on the right of the graph, what represent?

what do you mean? What is its unit?

I can not extract the material properties of a structure from the CST studio suite. Whenever I set the effective thickness of the material to the Substrate thickness, I get a template-based post-processing error (

*See the attached Screenshot*). What is the reason for it?**What does it mean by**"**effective thickness of the material**"**?**Does it mean the substrate thickness? Please help me extract the material properties with CST. Any suggestions will be gladly appreciated.Metamaterials can have exotic material properties. I have come across some metamaterial papers in which the effective permeability or permittivity can be negative. Is it possible to possess positive effective permeability or permittivity by any metamaterial design?

i am doing work in acoustic metamaterial and i have no idea how to do simulation . thats why i want to know simulation of a sonic crystal in brifely

Hello all,

I am working on metramaterial these days,, and I got confused about Negative phase velocity and positive group velocity in metamaterials. I know how to obtain the equations but I can't understand how a wave can have Negative phase velocity (the direction of the wave), but the power propagates in the opposite direction. How would it be possible?

There are so many papers where they select different materials for forming metamaterial also use different substrates as well as liquids that evaporate. What interests me most is which materials show the best result to form metamaterials that can be used for nanoantennas. Thus I want to know what to select for forming metamaterials.

I found on comsol database one online webinar/workshop where a terahertz metamaterial was modeled and there, input "(px*py/4/2/Z0_const)*E0^2" this equation is used. I need to know why is this used?

There are so many papers where they select different methods for forming metamaterial. In some papers, they used AC sources in others DNA origami and so on. What interests me most is which exact equations show the result to form metamaterials. Thus I want to know what to select for forming metamaterials.

Any reflective surface of the dielectric material increases the gain of patch antenna, but when metamaterial is used as a superstrate layer on the patch antenna why the gain is improved more? What is the difference between any reflective surface and metasurface in the case of patch antenna?

In the comsol simulation of the elastic wave metasurface, what module is used? How is the incident field of a periodic unit set (boundary load/specified displacement)?

And for example, when the longitudinal wave is incident, how to integrate the amplitude (p0, p1, p-1, s0, s1, s-1) of each diffraction order of the longitudinal wave/transverse wave?

Greetings to everyone,

Can anyone please tell me which parameters settings are used in a simulation of metamaterial and metasurface unit cells in CST? (Background, boundaries, global properties, etc. )

for a Perfect metamaterial absorber how we can find Absorptivity with different angles of ring rotations in HFSS software?

I want to simulate this using the Acoustic structure interaction module.

For ease this can be done by taking a single unit.

How can I do this in comsol?

Is there any open source code (C, C++, Python or Matlab) for discrete dipole approximation for scattering problems in a complex dielectric medium ?

I am looking for the latest approaches to find the band-gap of Phononic / Periodic materials. In this regard, if anyone knows a reference (in detail) for Finite Difference Time Domain (FDTD) theory along with the Bloch method, please share.

I really appreciate any help you can provide.

Does the wavelength the unique criteria to choose the size of unit cells in metamaterial regime ? particularly for microwave applications.

I have designed an antenna whose gain I want to increase,pls suggest how to see which metamaterial will fit in

I see professional advice to help to attenuate a highly directional interference.

We have a large (~3m) satellite dish antenna for collecting earth observation data. This antenna rotates to scan the sky and works in an 8 GHz band. Unfortunately, a point to point wireless link interferes with the reception during certain hours, and we cannot shut them down due to difficult legal processes.

We have built a metallic wire mesh screen, but it seems to have only a low effect (maybe because of mesh cell size or overall size ... but we are unfortunately limited due to the wind load).

We are considering using frequency selecting structures (FSS) or metamaterials/metasurface to create "negative gain" and thus attenuate the waves coming from the specific direction of the interferer.

**Would you mind suggesting some good references to assist with designing such a low-wind-load structure, or perhaps better ideas?**

With thanks,

Albert Lysko

Dear all,

I recently meet a problem when I use RCWA codes.

In the same structure, it tooks fewer time when using the FDTD solution.

I need set a lot of orders to calcuate the structure which can reach the similar result.

So I have a question that how can I judge the accuracy of the simulation when I use RCWA codes? and How to judge the orders I need?

Thanks

I am trying to simulate THz metamaterials in CST Microwave studio where the transmission needs to be studied with varied amplitude of the excitation signal and the field confinement in my structure in each case. Would highly appreciate your suggestions on this...

TIA.

I am currently trying to simulate a THz metastructure in CST studio using the frequency domain solver. I would like to know if it possible to change the field strength of the incident radiation. TIA.

**1.**How to assign waveport when top conductive pattern (patch) is smaller than the substrate size? Any reference from where the details can be seen ?

**2.**Master/slave boundary and waveport excitation are not compatible either in this scenario. Without assigning master/slave boundary conditions, can we get accurate dispersion diagram?

**3. Unit cell analysis of a linear array (extending only in one dimension)**is required. I have found "Unit cell analysis of a Two-D array (for instance, EBG structure)" but in that case port assignment is a totally different scenario.

I don't want to assign Floquet Port on top/bottom of the air box.

Unable to understand the slide number 3 mentioned in the picture.

Thanks for any help!

Greetings to all!

How does metamaterial affect antenna Gain and Bandwidth? What are the physics behind them.

I have designed a split ring resonator with a metal ground so my S21 is zero. How can I plot the permittivity and permeability and impedance in HFSS?

Since I have used metal ground I also can't find the phase of S21.

Hi,

I'm trying to simulate a split ring metamaterial from this paper ' - μ Compact magnetic metamaterial lens for 0.35-T MRI' by Hassan Ali et al 2017 in CST Microwave Studio but I'm unable to achieve any resonance in the expected frequency of around 14.88 MHz. I'm unable to get any resonant behaviour in the megahertz range at all. Could anyone check to see if I'm setting up my simulation correctly?

Hi Community!

I want a detailed answer or document in which I got to know how you can design a unit cell of metamaterial for a particular frequency and how to bring periodicity to the structure. I have searched a lot but couldn't find an appropriate answer. If someone has the document related to it or had experience in it then kindly help me out.

Thank you!

I have already simulated the design and of course I get absorption rate as 99.91%. how can i calculate the impedance vs frequency for absorber in cst?

If in the antenna design only one SRR structure is used, so can it be also called as Metamaterial based antenna, any literature suggestions for such type of antenna structures.

Dear Sir/ ma'am

When I am doing a simulation of a unit cell of metamaterial in CST, I am getting a warning "mesh adaption termination because of maximum passes is reached". What is it and how much it affects the simulation and to avoid it. I reduced the frequency range from 4 GHz to 1GHz but still, I am getting the same warning. Below I have attached the image of the warning.

What's the application of metamaterial with respect to acoustic propagation in engineering?

My design contains three parts.

A silicon rubber membrane is placed between upper and lower part.

I want to calculate sound transmission loss by using comsol Multiphysic.

There are lots of module inside Acoustic section.

Which module will be suitable for this??

Hello Dear Researchers,

Is there any guidelines or mathematical formulas (or any reference) on how to calculate the dimensions of the unit cell for metamaterials, metasurfaces or Artificial Magnetic Conductor applied to Antennas or Filters ?

Thank you in advance for your assistance...

I designed a 3x3 metamaterial resonating at 28GHz, the return loss is fine but the gain is negative. How can I improve it and also are there any applications of negative gain?

Dear sir/ma'am

I have designed a metamaterial absorber(MA) with a bandwidth of 2GHz w.r.t. 50% i.e. at the full width of half maximum in X-band. My question is whether the bandwidth of a MA is accepted at this value now?

Absorption vs Wavelength Plot w.r.to Temperature.

All artificial metamaterials have a periodic arrangement of cells or pieces of metamaterial with a period or several periods that are small compared to the wavelength.

Can there be metamaterials with a non-periodic structure?

**1)**

**Series capacitance and shunt inductance provide left hand (LH) behavior.**Two mushroom patches gap-coupled with each other, to realize a CRLH TL zeroth order resonator. A single patch is unable to provide series capacitance so Number of unit cells (N) is not equal to 1. Am I right? In this case

**what would be the correct "Number of unit cells"?**

According to my understand N = 1.5, because one patch antenna contributes whereas the series capacitance is shared with the second patch, so can we consider it as 1.5 cells?

**2)**How can I obtain dispersion graph of such a structure?

**Periodic boundary conditions**(PBC) are applied on a single element (unit cell) and infinite elements are taken into account to get dispersion graph, or bloch impedance etc. When I considered a single mushroom patch, and apply periodic boundary conditions (PBC) in HFSS, the resonance frequency values on dispersion diagram (beta vs frequency) are not correct. As expected, considering a single patch means we are ignoring the series capacitance which otherwise exists between two patches.

**How can we apply periodic boundary conditions (PBC) on two gap-coupled patches?**

**3)**What is the

**fundamental part/phenomenon of circuit which gives rise to multiple modes in a mushroom structure?**I am talking about non-zeroth order modes.

**Do the higher order modes (1st, 2nd, -1st, -2nd etc) always exist**unless otherwise suppressed by applying some techniques?

Is it just a matter of representation that we select/show only a small portion of frequency spectrum (owing to desired frequency band/area of interest)?

Thanks in advance!

Dear sir/ ma'am

I am designing a metamaterial absorber based on a split ring resonator. Now I want to design its equivalent circuit in terms of R, L, C and want to calculate its R, L, C value. Can anyone suggest the books, or NPTL video or any lecture videos, or paper,s, etc. to get the fundamental idea about equivalent circuits?

How to convert solar energy to electrical in solar cells for Metamaterials nanostructure? what is the principle of operation? How we connect wires to the cells to output the energy?

I have been trying to model elastic metamaterials in COMSOL with periodic condition (& floquet theory). While I have been successful with the 2D case, in 3D model of the same structure, I just don't get a bandgap. I have applied the same boundary condition on the same opposing faces (edges in 2D & surface in 3D) in the x-axis. I have attached the 2D & 3D models with their respective Dispersion plots.

I don't understand as to what the issue is here.

I am using copper plate at the back side of my design. And I vary the length of air box (which is used to assign master/slave boundaries and for incidence of wave through floquet port) at the back side of absorber. Because of the copper plate at the back side, absorptivity should not vary even though length of air box at the back side had been changed. But it is varying, why?

I am also attaching the HFSS files, go through it

Can anyone help me? Thanks in Advance.

I need details description about metamaterials simulation On CST MWS.

Also please refer some fundamental books regarding metamaterials absorber.

Is there any specific website for getting permission to use images and contents of paper of journal, for writing a review paper?

im working now on TPV solar cells and metamaterials and i realy need our help in CST microwave i have a tpv cell simulation and i want to extract particullarly the absorbtion of only the active layer ( cell composed of multiple layers) how i can do that; and also i want to know how to extract the short current density of the cell based on optical properties (basically same question)
thanks in advance

Can I please ask for good articles/papers/ thesis on Flat Lens Antenna to study? Is it metamaterial or antenna having a metamaterial at the back?

I am looking at this:

Trying to understand what is this?

Thank you

How to calculate the input impedance of patch antenna? How it can be solved in an easy way without using bessel function?

I am having trouble setting up this problem in HFSS or FEKO. In HFSS, I've tried both FEM and FEBI-IE solvers. With FEKO, I've tried it's MoM solver and default settings. I am would like model model two horn antennas, one in transmit mode and other in receive mode, with a dielectric slab of material in between them. After running the simulations, I'd like to export the s-parameters to apply a material retrieval algorithm like Nicolson-Ross-Weir (NRW) or Newton Raphson to get the permittivity & permeability properties of the dielectric slab.

Link to a paper describing what I'm trying to achieve is below but it was done using CST:

Conference Paper Free Space Measurement Technique on Dielectric Properties of...

Dear all,

Now I'm selecting FEM for design of metamaterials on NIR~VIS frequencies, and keeping 3 software: ANSYS HFSS, COMSOL with wave optics module, and CST STUDIO SUITE.

Could you give me your ideas for these softwares?

I don't mind the price of them.

Sincerely,

Yuta Imade

Is it possible to get S11 parameter greater than 0 dB in case of metamaterials?

In order to enhance the antenna parameters, meta-material unit cells are added but where to load them is more advantageous either at ground plane or at the patch side, also is it necessary to add them in array or single unit cell can help. The target frequency band is UWB.

a unit cell of metamaterial has to be analyzed in simulation using hfss. The solution frequency is 10 GHz and range is from 5 to 15 GHz with sweep and interpolating linear step method.

Number of passes are 6 but i am getting these errors -

Discrete solution,process hf3d error:Failure in solving matrix

Solution setup 'setup1',Sweep 'Sweep':Interpolating sweep did not converge.

Simulation completed with execution error on server: Local Machine

Dear all,

I'm looking for theoretical or analytical method to design meta-atom, metasurface, and metamaterials. I only know transmission-line theory.

Would you tell me the good keywords to advance my study?

Sincerely,

Yuta

Hi all,

I hope everyone is doing well and is in good health.

I want to simulate a Honeycomb Core Geometry Sandwich Panel Metamaterial with COMSOL Multiphysics for sound transmission study. It is needed to use

**beam elements of quadratic geometry order**to create the geometry of unit cell. In 2D I do not know how to do that! Do you have any idea about it?I appreciate your time and consideration.

Hello.

I'm working on transmission metasurface at 60GHz for focusing wave, but I can't simulate full structure by Frequency Domain solver because the error in my system '' is not enough memory'', can you guide me that how to simulate by high accuracy in CST?

my system has 4 core and 32 GB RAM

Thanks, Best Regards.