Artificial Magnetic Conductor (AMC): Reflection Phase, Unit Cell Design & Floquet Port in HFSS

[@mohranger5256]

Hi Before i didn't know how to simulate antenna but with your great video i improve my skill in hfss and cst now i can simulate any paper about antenna also design antenna .if you get free time please upload more video with CST & HFSS Thank you sir you help me a lot

[@tensorbundle]

You are welcome

[@jaziaibrahim2431]

Thank you for this beautiful video from I get this research paper I will work on a report on it

[@tdf-ng2bj]

This is great and informative❤

[@aartibansal6671]

Hi, its a very informative video..I request you to kindy explain AMC designing in cst studio software too..

[@engineerx7180]

Dear Sir, if possible Please make a similar video in CST as well. Thanks

[@tensorbundle]

Thank you. I will try my best

[@YAHYAMOHAMMEDSINJABTMB]

@@tensorbundle yes please, we really need it asap

[@SayedAbbasShah-hx3cc]

Hi sir, you explain every very clearly and efficiently but one thing I don't know that how can we calculate the parameters or dimension for our desire AMC.

[@sadhanamh4576]

In which frequency the AMC will be operated Thanking you

[@yyyyhhhh396]

Very good 👌

[@范得倫]

It's clear. Thank you!

[@tensorbundle]

You're welcome!

[@shalikramrajpoot5588]

[error] Port 'FloquetPort1': The exterior boundary of the faces for a Floquet Port must consist of pairs of parallel and equal length segments, displaced from each other by an integer linear combination of the lattice vectors. (2:55:10 PM Jan 22, 2025) why i am facing this error in my project.

[@hemantprajapati7066]

Thanks for nice webinar

[@tensorbundle]

most welcome

[@sciencelearning2326]

I hope you will do the same simulation in CST as you promised us

[@Mezo-gamerYT]

Thank you.... can i know why S11 and S22 are not identical? and what port 1 and port 2 means? Also, i want to know how i can measure the far field pattern to obtain the phase shift of the mainlobe in the case of varactor based RIS?

[@sciencelearning2326]

When you will make a video on how to simulate AMC in CST as promised before?

[@Swamyperspect]

thank you for valuable content

[@tensorbundle]

My pleasure

[@alkayadav6001]

Thanku Sir... Is there any video which can explain the design of antenna using array of AMC...

[@hodarezaei]

thank you, sir. how can define the number of amc arrays in hfss in this method

[@mahfuzurrahmantalukder6210]

Thank you for this great webinar.

[@tensorbundle]

thank you

[@shabnamara2160]

Sir is there is any formula to calculate the dimension of unit cell, as i know that max dimension is lambda by 10.of unit cell.i am regularly listen your video very informative lecture.

[@benammarabdelkader4013]

for the Analytical 1 how we assigne the wave port?

[@mullasajeed381]

You have set the height of the box to lambda/4 (80mm), but for a design frequency of 5GHZ, the lambda/4 = 15mm.

[@tensorbundle]

taking larger box does not matter. If it was smaller, then would have mattered

[@tensorbundle]

Lambda/4 is the minimum distance. We can take larger distance than that. No harm in it.

[@jane3598777]

Hello! Sir, what if AMC metal has thickness, what is the distance of the de-embedded would be? is box height minus the substrate thickness and metal thckness ? or only minus substrate thickness? thank you !

[@beaughosh1739]

Sir, What will be the dimension of substrate during single unit cell analysis using floquet port ? Is there any specific formula for substrate size during single unit cell analysis ? Please suggest me.

[@lajpaal]

Very informative video, Hassan. Why distance of the floquet port is kept at 80mm? Shouldn't it be lamdba/4 at lower frequency of sweep?

[@tensorbundle]

Lambda/4 is the minimum distance. We can take larger distance than that. No harm in it.

[@sciencelearning2326]

Thanks a lot, Mr.Hasan for this video, could you Make a video for the same thing "Artificial Magnetic Conductor (AMC): Reflection Phase, Unit Cell Design & Floquet Port " in CST

[@tensorbundle]

thank you. I will keep it in mind.

[@sciencelearning2326]

@@tensorbundle I hope that, Thanks

[@engineerx7180]

Great and explanatory Video, Thank You, Sir. Dear Sir, Please make a video in CST as well.

[@ABUHENAMURSHED]

@@tensorbundle Sir I m highly looking for your video for the same thing using cst, hope it will be available soon.

[@pallaviait5791]

Thank you for this webinar. Very informative. Sir, I have designed a rectangular patch antenna with the coaxial probe, and the resultant gain is around 2.5dB. Is it possible to maximize the gain using AMC for 1.06GHz? Is it possible to place AMC unit cells on the designed patch?

[@tensorbundle]

yes possible. There are some research papers reported where they used AMC as superstrate on top of antenna to increase gain

[@pallaviait5791]

@@tensorbundle sir, how to calculate the dimensions of unit cells? Is there any formulas? Once we design the unit cells, then how to place that structure on the designed patch?

[@pallaviait5791]

I have designed an antenna for 1GHz, and I am getting 2.5db gain. I have to improve the gain of the designed antenna using metamaterials.

[@tensorbundle]

@@pallaviait5791 Please check the following research papers: 1.Prakash, P., Abegaonkar, M. P., Basu, A., & Koul, S. K. (2013). Gain enhancement of a CPW-fed monopole antenna using polarization-insensitive AMC structure. IEEE Antennas and Wireless Propagation Letters, 12, 1315-1318. 2.Feresidis, A. P., Goussetis, G., Wang, S., & Vardaxoglou, J. C. (2005). Artificial magnetic conductor surfaces and their application to low profile high-gain planar antennas. IEEE Transactions on Antennas and Propagation, 53, 209-215.

[@pallaviait5791]

@@tensorbundleThank you sir.

[@daibinjing598]

Hello sir, if patch antenna and AMC using the same size， Can the antenna increase gain？

[@basemaqlan2296]

Thank you, Im wondering why you avoid to do that in CST software

[@tensorbundle]

No reason! The principles are also same in CST. Being an American company, HFSS has more dominance and uses in academia in all over US/Canadian universities compared to European-owned CST. Perhaps that's the reason.

[@小松猫]

Dear Sir I am trying to design a Circularly Polarization reflective metasurface. I want to know, how to get the accurate circularly polarized reflection parameters when I try to illuminate the unit cell with a circularly polarized excitation wave. I set one Floquet port having two modes, 90 degree out of phase from each other. After simulation, I am able to plot the (FloquetPort1:1,FloquetPort1:1); S(FloquetPort1:2,FloquetPort1:2); S(FloquetPort1:2,FloquetPort1:1); S(FloquetPort1:1,FloquetPort1:2); But they both seem to represent the linear polarizations. How to get the circular polarization, like S(RHCP,LHCP);S(LHCP,LHCP). Is there any formula to calculate it? Thank you.

[@黃子宸-l8w]

What is the principle of floiquet port? Why should we use it to get the result of the changing of phase?

[@tensorbundle]

Please kindly refer to CST or HFSS help documentation. They wrote in details about Floquet port in the documentation. It is difficult to convey details in limited space of comment section

[@edu_related8371]

Thanks for the video sir, Which one is better Floquet port or Wave port. Kindly clarify sir...

[@tensorbundle]

Floquet has certain advantages such as it can model inclined incidence wave. Waveport cannot consider inclined incidence wave- it can only model normal incidence wave to unit cell

[@edu_related8371]

@@tensorbundle Thanks for the reply, you are very helpful. keep doing it.

[@MMbass420]

Thanks for the video! Is there any case in which you'd assign a radiation boundary in addition to the floquet port? Thanks

[@tensorbundle]

no, floquet modes require periodic boundary condition (PBC), hence side walls are always modelled as PEC and PMC boundaries

[@MMbass420]

@@tensorbundle Thanks for that. Does this imply that there should not be a Rad_BC at the Floquet port? Also, What if there is a transmission line below the GND plane. Should there be a rad_BC at the bottom of the unit cell?

[@tensorbundle]

@@MMbass420 1. Yes no rad_BC at floquet port 2. If you have a full ground plane in the unit cell, the ground plane itself acts as a PEC boundary, hence no need to separately define any rad_BC even if there is any transmission line below ground. Anything below ground does not impact reflection coefficient condition due to ground's inherent PEC boundary condition,

[@MMbass420]

@@tensorbundle Great! Thank you

[@abhirammondem8036]

Thank you so much sir, but are there any design equations for the dimensions for an unit cell ? As they form an array the dimensions really matters!

[@tensorbundle]

These unit cells are mostly modelled by lumped RLC circuits and an initial design is started with some known basic structure such as a rectangular patch, ring etc. Then more complicated response can be optimized using trial and error

[@som_media]

I don't know why I can't click the Floquet port. Someone help me, please.

[@khanhlinh286]

Sir, I want to simulate an 3x3 reflectarray to get reflection coefficient and reflection phase. How should I set the boundaries for an array? Thank you.

[@tensorbundle]

You can apply Radiation boundary. Alternatively, using FEBI and PML boundaries also yield similar results

[@عرفانگلابدار]

good

[@bidhandas6418]

please make a video for designing it in CST Microwave studio.

[@tensorbundle]

okay thanks for suggestion. I have thought of it before to make. But time does not allow me to make it

[@dilsediltak4ever]

Please make video in this topic in cst studio software.

[@tensorbundle]

I will try. thanks

[@shabnamara2160]

Thank you sir for this webinar. i want to ask one question in hfss you put height of unit cell is lambda by 4 .at 5 ghz is height is 15 mm but you put 80mm.how?? plese clear this

[@tensorbundle]

Have you listened to the audio while playing the video? If you watch the video again, you will hear I said "at least" quarter-wave length. "At least" means "minimum" in English. If something is "at least X quantity", mathematically this translates to "greater than or equal" to X.

[@shabnamara2160]

Thank you sir

[@shivangidixit3615]

Please can you help me to do the same in CST software

[@SalahAli-h2g]

Hello Sir,what is the name of designing program at time12:49?

[@sciencelearning2326]

and if I have transmit FSS unit cell what I should put for floquet port for get S21 and what will happen to the reflection phase in this case FSS unit cell?

[@tensorbundle]

you need to define two floquet ports (up and down) for transmittance phase

[@srabontysoily5185]

Sir, what about wave port and pec/pmc boundary in hfss? Can you please make one tutorial on that?

[@tensorbundle]

Considering the unit cell being embedded into a box that has six planes in total. The wave port is defined at the top plane and must be de-embedded to the surface to the Unit cell. The PMC and PEC are to be defined on the four side planes with co-planar configuration. If the unit cell has a ground beneath, no need to assign any boundary at the bottom plane since ground plane overrides it.

[@srabontysoily5185]

@@tensorbundle thank you sir, it would be helpful if you made one video with wave port creation in the unit cell in HFSS

[@anettantony7252]

Sir, can u do a video on finite array FSS using HFSS

[@tensorbundle]

I will try. thanks

[@bismaarif3878]

Sir how make 4 by 4 array

[@prabhakarkumar932]

can we optimise this design for broader bandwidth in hfss?

[@tensorbundle]

Yeah, you can use thicker substrate unit cell to increase the BW

[@MEKANAVEENAPHD]

what about array sir

[@johnatkinson3218]

I sent you an email regarding floquet ports.. thanks!

[@arulmurugan7336]

In Reflection Phase degree - why -90° to 90° consider as bandgap sir.. why not 45° sir??

[@tensorbundle]

Actually both conventions are used. -90° to 90 convention was introduced by prof. Sievenpiper and 45° was introduced by prof. Rahmat-Samii's research group.

[@antennaresearchgroup5972]

Radiation Box height should be more than 15 mm but you have taken 80mm???

[@tensorbundle]

taking larger box does not matter. If it was smaller, then would have mattered. Lambda/4 is the minimum distance. We can take larger distance than that. No harm in it.

[@double_u_oong1517]

I am not good at listening English. Are there any related papers or documents?

[@tensorbundle]

I am sorry. I do not have written document.