Material Microwave Absorption in CST

[@jeannorman8162]

Finally, someone share how to simulate microwave absorption of material in CST. Big Thanks. 👍

[@LYSStuff]

Welcome

[@hamzaasifkhan8421]

can you please explain the s-parameters results of band stop and band pass filters, thanks

[@rimgo9208]

Hello, thank you for sharing. I am a student in China. My research field is also on absorbing materials. Thank you very much for sharing the CST simulation and thank you very much for sharing the video of absorbing material simulation. Can I repost your video on the Chinese "bilibili" video site? "bilibili" is a Chinese youtube

[@LYSStuff]

Hi, my pleasure. You are free to use my video as long as you give credit. :)

[@rimgo9208]

@@LYSStuff Thank you very much, your CST absorbing material video is of great help to me, and I would like to extend my high regards to you

[@attadaphanendrakumar8984]

How to make sure it's TE mode or TM mode. Please explain, how to get specially TE mode or TM mode

[@LYSStuff]

Hi, in CST --> 2D Results--> Port Modes --> ()for Example Port 2 --> click on e1 or h1, and then read mode type. Depend on your design and waveguide port (port mode) setting in CST. If you need more information, may refer to CST help file. For my case, is TEM mode. You can try to simulate rectangular waveguide and check on TE mode, default is TE01 as usual.

[@nirmalkumar.r5146]

Hi , hats off to you for the video..... I am just learning kid in this simulation,... I understood that template used here is MW & RF & OPTICAL | Antennas , but may i know which workflow is used in this video waveguide, planar,wire,phased array,reflector,dielectric resonator,RFID,5Gmmwave,Mobile device. could you please tell me...thank you

[@LYSStuff]

Hi, thanks. The workflow is use is Waveguide. unit in cm and frequency in GHz. Hope it helps. :)

[@muhammadfathullahry4123]

Hello Dr Lee.. can you show and teach how to design a multi layer RF absorber?

[@LYSStuff]

Hi, please refer to this Video "kzbin.info/www/bejne/i3zJgImaqtxkgK8". Hope it helps. :)

[@kabirshuvo104]

Hi, I have a query. How can I plot the abosrption vs temperature graph in CST? As thermal stability of material is depends on its temperature, so I think the absorption will change with respect to temperature. But how can I measure this?

[@LYSStuff]

Hi, yes. You are right, the absorption will change with respect to temperature. But in CST simulation, only able to set the temperature on the material. Because the temperature actually effects on permittivity, permeability and conductivity parameters of the material classes. Once the temperature changed for a material, it will change the values of material permittivity, permeability and conductivity properties over the frequency range. Example, the changed value of material permittivity will effect on the microwave absorption. The temperature dependency curve can be defined in the Temperature Dependent Materials. After definition the material table can be visualized as a 1D plot by selection in the Navigation Tree.

[@LYSStuff]

I not sure about the plot absorption VS temperature graph in CST. Because it will be specific at single frequency. I think we only able to set the thermal of the material value with variable. The parameter sweep the variable of material thermal value. And the graph still S11 vs Frequency with various of thermal sweeping value. Hope it helps. :)

[@fathzakaria1174]

Thank you sir, very clear explanation.. but how about if the material that i want to use didn't have in the "Material Library" ?

[@LYSStuff]

Hi Fath, you may define any New material in CST. For your reference, you may refer the link below: 1. How to Define New Material in CST kzbin.info/www/bejne/fJKVZKKEesqcr8k 2. How to Add New Material in CST Library kzbin.info/www/bejne/aqq8eZ9pftCUetE Hope it helps. :)

[@nirmalkumar.r5146]

hi , i just replicate what you did in this video...but when i start solver.... it shows this type of error Port number 2 and 3 have overlapping areas in mesh representation. Consider to decrease the port dimension or to refine the mesh distribution. may i know ,where to rectify this mistake

[@LYSStuff]

Hi, in my video, only using Port 1 and port 2.

[@sam-rh3jo]

Thank you, your video is very helpful for my study. If you are convenience, could you please tell me how to show the electric field changes in 3D.And how to observe surface electric field of shielding materials.

[@LYSStuff]

Hi, my pleasure. For E-field, u may refer to this video how the E-field and surface current flow kzbin.info/www/bejne/a3zEc2OOfr92oLc Hope it helps. :)

[@sam-rh3jo]

@@LYSStuff thank you very much!

[@rimgo9208]

Hello, for this simulation case, what project template should I choose? Should we choose EMC/EMI Radiated Emission or Radiated Susceptibility? Or something else?

[@LYSStuff]

Hi, I'm using Microwave & RF Template--> Antenna. The simulated results are convincing.

[@rimgo9208]

@@LYSStuff thank you very much

[@scottishprofessor-h9l]

It is a nice presentation. However, you are using a "lossy metal" material type for aluminum. Lossy metal in CST is opaque (it has a surface impedance with NO EM fields within it) to electromagnetic fields and is not the best material choice for this.

[@LYSStuff]

Thank you, but we should choose lossy material for the simulation because Lossy medium:- It is the medium, where the EM wave loses its power. And it aalso defined the conductivity value for the aluminium. Lossless medium:- It is the medium, where the EM wave does not lose power. Most of the material is not ideal material as perfect conductor.

[@Razorex3]

Hi, love your videos... May i know is there any references behind the theoretical parts that u hv shown in the videos? Tq

[@LYSStuff]

Hi, Thanks. For references, you may refer to 1. www.frontiersin.org/articles/10.3389/fmats.2021.633079/full 2. www.jpier.org/PIER/pier140/44.13042407.pdf 3. link.springer.com/article/10.1007%2Fs00339-018-1564-y 4. www.researchgate.net/publication/341910876_Microwave_absorption_study_of_dried_banana_leaves-based_single-layer_microwave_absorber Hope it helps. :)

[@hoangthinhle4311]

may I ask why you set you boundary condition like that (Et=0 in X axis and Ht = 0 in Y axis). Thank you

[@LYSStuff]

Hi, this is to create a TEM waveguide and the plane containing the "WaveGuide port". Due to my design is symmetry, I can set (Et=0 in X axis and Ht = 0 in Y axis) or (Ht=0 in X axis and Et = 0 in Y axis), It will get same result. You also can set the boundaries condition to symmetry plane. CST Microwave Studio has a symmetry setting located in at Simulation->Boundaries->Symmetry Planes. You may refer to this Note: throberts.blogspot.com/2016/08/notes-on-symmetry-using-cst-microwave.html Hope it helps. :)

[@hoangthinhle4311]

@@LYSStuff can you show me how to set boundary condition if my design is not symmetry?

[@LYSStuff]

Hi, you can set this (Ht=0 in X axis, Et = 0 in Y axis,Open in Z axis, then set distance at "background option" ). The setting is same at my video just change the Ht=0 in X axis, Et = 0 in Y axis.

[@hoangthinhle4311]

@@LYSStuff can I use open (add space) in all coordinates instead?

[@LYSStuff]

Yes you can, if your simulation is an antenna design with waveguide port (sma). If you plan to simulate like this enclosure direct to the same, then the boundary condition should be as previous mentioned setting.

[@cemalaka5812]

Could you please help me about calculation of reflection loss in excel or origin?

[@LYSStuff]

Here is the calculation of reflection loss, you may refer to this video kzbin.info/www/bejne/famvZWmYp9ujaLM

[@cemalaka5812]

@@LYSStuff thank you for help but ıt doesn't help me because complex numbers are given error somewhere so I can't fix it. Thank you for attention.

[@LYSStuff]

@@cemalaka5812i see, RL(magnitude) =sqrt((real) ^2+(imag)^2)

[@cemalaka5812]

@@LYSStuff actually main problem in Zin calculation

[@LYSStuff]

@@cemalaka5812 for Zin, you may refer to this video kzbin.info/www/bejne/qJichJuaZ7eigpY

[@mohammedkhamess8882]

hello . please could you show the effective the distance between ports and MUT

[@LYSStuff]

Hi, at 05:33, you may found the setting for the distance. With the boundary condition setting, the distance of port doesn't affect much on the absorption. Because the wave is guided.

[@mohammedkhamess8882]

@@LYSStuff thank you. please could you help me to measure the electric permivivity by CST program

[@LYSStuff]

@@mohammedkhamess8882 Hi, We can measure permittivity using CST. We only can extract permitivity and permeability of Metamatarial using CST you may refer to video below 1. kzbin.info/www/bejne/i32mnI18rbeKapY 2. kzbin.info/www/bejne/bqm8fayMZZlrns0 If you wanna to define permittivity material by ourselves. you may refer to this. kzbin.info/www/bejne/fJKVZKKEesqcr8k Hope it helps. :)

[@matteofouquer8976]

Can uyou help to make a measurement of shielding effectiveness on simple sheet ?

[@LYSStuff]

Good idea. Meanwhile, You may refer to this paper 1st. www.researchgate.net/publication/322507892_EMI_shielding_based_on_MWCNTspolyester_composites

[@The_expanding_Universe]

Hello any youtube Channel or course anyone knows about to learn the CST for EMI shielding applications. Please let me know, i'll be thankful

[@LYSStuff]

Hi, I only have these related to shielding application kzbin.info/www/bejne/famvZWmYp9ujaLM kzbin.info/www/bejne/rX3SZHuZjJ6rZ8k I didnt found any useful CST EMI shielding video or course in youtube. But you may refer to ETS lindgren, R&S or Keysight for EMI shielding application

[@johnatkinson2410]

I seem to get diff results - with exact same settings for first part.. at 4 GHz my S21 is -1.12 dB

[@LYSStuff]

Hi, this is rare. Maybe can check on the material part. Used same material as well?

[@johnatkinson2410]

@@LYSStuff I seem to have same CST version - yes wood, same distance, same symmetry, freq, mesh etc

[@johnatkinson2410]

@@LYSStuff I have 2022 version CT as well, wood params look the same as yours..

[@LYSStuff]

Hmm... If everything is the same, I also no idea why different results. Sorry.

[@muhdhamizie530]

may i know project template? MW & RF > ANTENNA > unit cell or what ?

[@LYSStuff]

Hi, is Transient solver. You may refer to 02:41, the "setup solver" is "T". Hope it helps. :)

[@muhdhamizie530]

@@LYSStuff if i need to design microwave lens/ unit cell , can you suggest me project template or any related video?

[@LYSStuff]

Len design usually is single Len. Therefore no need to use unit cell. Antenna template is fine.

[@matteofouquer8976]

HI ! Can i use your setup to make a shielding effectivness measurement ?

[@LYSStuff]

Hi, yes. Is the same setup. Just Shielding effectiveness mainly focus S21 with SE material and without SE material.

[@matteofouquer8976]

@@LYSStuff OK ! But how S21 can be bigger with wood sheet than an aluminium sheet ;-(

[@matteofouquer8976]

@@LYSStuff Is that possible to get your email adresse to talk ?

[@LYSStuff]

For sure aluminium sheet, S21 has lower power receive compare to wood sheet.

[@matteofouquer8976]

@@LYSStuff do you have a formula to convert S21 and S11 to SE