CST tutorial: Frequency Selective Surface (FSS) design - unit cell design & array full simulation

[@killerr106]

Great tutorial! simple and direct, there's no more resource available out here so thank you for your time. I'm working in reflectarray and would love to see you doing on about it

[@aekBenammar]

Hello,Why in the Begining you did not take periodique structures instead of Planar antennas?

[@Mr.BhupendraSharma]

Thanks for your video. As you have described the reflection of incoming waves. I want to ask about how we can get simultaneous reflection and transmission using the FSS structure?

[@abhishekkarwa3674]

can it be done in hfss,,,,put a video of that.....how the dimensions of ring and substrate are decided. please help me out

[@MassiveMimo-rn3we]

Can you help me in designing SRR array and CST-MATLAB API please?

[@johnatkinson3218]

As always very interesting - thank you!

[@wilfridrm9679]

Hello Mr., your tutorial is very instructive. I have a question, how do you determine the different radius so that the structure resonates at the resonance frequency? I have a fused ring resonator and I'm having trouble finding the exact radius so that my structure resonates at my frequency (knowing that R=c/(4*pi*f0*sqrt(Epsi_eff))).

[@Nadu_remanesc]

Hello! Thanks for the video, really interesting. I have a question, you mentioned that the surface is reflective but based on the radiation diagram, approximately the same amount of power that goes through the estructure is reflected (you have two lobes instead of one), why is that happening?

[@CityLifeVoyager]

Thank you for informative tutorial!

[@nitikyadav7069]

Thank you for such a wonderful explanation.......can you please make a video on how to calculate dimensions for a particular frequency?

[@antonyjudice4417]

Very useful videos. If possible, post any wearable antenna design with SAR analysis . Thank you so much

[@puzzlesgames485]

How to simulate diode using S2P file for ON OFF purpose in CST using Schematic

[@abdullahmadni5192]

How can we check that the FSS is acting as an absorber ?

[@jacobrandall4891]

He mentions this device is either transmission or reflection so I'm guessing this specific design doesn't absorb

[@mdsazid3221]

I have a ques Should we need to design ground in metasurface? If anyone know please answer it

[@shilpajangid6974]

sir, if I placed metamaterial array over the patch return loss is giving good result but gain will be decreased, why?

[@saadhassankiani4827]

Dear Nazmul Hassan, Please make a video on Substrate Integrated Waveguide (SIW) Antenna both in CST and HFSS

[@FahmidaLisa-nn4xw]

how to maximum transmission in cst unit cell design and array full simulation

[@GurmeetKaur-w6i]

Can you pls make a unit cell & array design for Reconfigurable intelligent surfaces It will really help alot

[@gazinafisrafi3418]

I designed a 6X6 for 0-5THz frequency It's taking 18 hours but still no result, how can I fix it? my PC has an i7 processor

[@hamzaasifkhan8421]

Hello Sir. Could you please guide me that how can we simulate an array using floquet port to get S11 and S21. As in this simulation you had used a plane wave which doesn't give us S-parameters. It's urgent as i need to submit paper. Your guidance will be highly appreciated. Thanks

[@tensorbundle]

Normally, S-parameters are useful for unit cell analysis. For array simulation, the analysis is done in terms for beam-pattern, power pattern e.g. the array indicates the collective performance of all the unit cells. That's why when we rather are interested in radiated field pattern/ power pattern/ beam pattern of the array not the s-parameters. The array works based on the assumption that free space wave hits the array surface and then something happens, and so we use plane wave engine to simulate the array. On the contrary, s-parameters assume that there is a waveguide port which is the point of entering the energy into the system. This s-parameters approach is more practical and suitable for unit cell analysis because during measurement of unit cell, we actually use a waveguide and put the unit cell at one end and then launch wave from the other end of waveguide and capture the S11, S21 etc.

[@saadhassankiani4827]

Could you tell about its phase? What phase shows

[@tensorbundle]

Please simulate the unit cell as show in the video and then you can click on "phase" plot in CST to check its phase. I did not show it in video because I was discussing about how much incident power was reflected. So I showed the reflection coefficient magnitude plot instead of phase.

[@AndriusKamarauskas]

CST benefits from GPU acceleration (With QUADRO GPU) in the time domain, but all periodic materials are modeled in the frequency domain 😐

[@MassiveMimo-rn3we]

For the unit cell gain is showing -200dB, am I wrong in the design please?

[@shilpajangid6974]

sir, if I placed metamaterial array over the patch return loss is giving good result but gain will be decreased, why

[@jacobrandall4891]

Good video thanks. Still not entirely clear why it acts like a PEC at the design frequency. The substrate is so electrically small thickness yet the copper ring can reflect. It would be helpful if you plotted the current distribution at 60 GHz to see whats happening

[@tensorbundle]

The metal ring introduces self-inductance due to the flow of charge within its circular loop, along with mutual inductance arising from its interaction with neighboring current loops. Additionally, the distribution of charge between adjacent rings induces additional capacitance. The successive capacitance and inductance configurations creates a low impedance surface at its resonant frequency. This leads to the formation of a stop band region, where the transmission of plane waves through the array surface is impeded, and the incident wave is reflected as though interacting with a metallic sheet.

[@jacobrandall4891]

@tensorbundle that makes sense, but we see it working just as good with the single element as a reflector which would have the minimum mutual capacitance/inductance. Characterizing the impedance can be very difficult without a ground plane. Typically when you have a substrate material backed by a conductor, a majority of the fields (when excited by some source) stay inside the material with the higher permittivity, and attenuate drastically as the wave propagates past the substrate. This energy isn't absorbed as heat necessarily, but rather would be reflected, hence the substrate may be behaving like a PMC as well where the substrate meets free space on the backside of the FSS. This could then be reflected. This reflection would be strongly dependent on the thickness of the substrate, which would be interesting to see what happens if the thickness becomes a significant electrical length. Just food for thought.. :)

[@MassiveMimo-rn3we]

@@jacobrandall4891 How does the circular ring fed? In the figure no physical feed is shown? I beg your sincerest response please?

[@MassiveMimo-rn3we]

@@tensorbundle How does the circular ring fed? In the figure no physical feed is shown? I beg your sincerest response please?

[@jacobrandall4891]

@MassiveMimo-rn3we there's a way to stimulate plane wave excitation. Not sure how I don't usually do it, but there's probably info elsewhere online

[@cihanderinoz]

How do I do it for 2.4 Ghz

[@tensorbundle]

you can scale the structure. For 2.4 GHz you need to increase the unit cell dimension (bigger cell). This also will increase your simulation time.

[@cihanderinoz]

@@tensorbundle thank you sir

[@amirb715]

your far field pattern is symmetric above and below the FSS so something is not right.

[@tensorbundle]

It is because the theta value was set to -180 to +180 which caused that symmetric field pattern up and below while the practical theta value should be set to -90 to +90

[@Kareem_iot]

very good , thank so much

[@Safhhf-tr6zn]

reflectarray

[@benedickfarley8072]

'Promosm' 😣

[@fouadomari1239]

thank you brother for your effort can plz give me your gmail for a collaboration , i visited your web site but i didnt know how to contact you . thank you a gain

[@jane3598777]

Sir, How to define the ring dimensions?