HFSS response in Terahertz range
Are the responses of HFSS simulations in Terahertz region valid or not?
Thanks
Regards
Hi
Actually According to my Simulations of Different Antenna (Broadband and Resonant Antennas) ,For Broadband Antenna i have not faced any problems but for Resonant Antennas i encounter Some Problem when i want to work Frequencies upper than 700GHz ...
After all , i Suggest you if you want simulate Resonant Antenna in THz Band , specially Frequencies more than 1THz ,CST Microwave is Best of all and Suitable for THz Antennas ...
HFSS is a full-wave solver that solves maxwell's equations with FEM techniques. Maxwell's equations are valid for all frequencies. What HFSS will not solve are quantum effects.
Hello PlanarMetamaterials
We are talking about HFSS capability in THz Region Not Validation of Maxwell's Equetion in All Frequencies...
Because HFSS Solve Electromagnetic Waves in Frequency Domain.it is difficult to get result frequencies upper than 1THz...
CST Microwave is Best of All...
In the last issue of IEEE Transactions on Terahertz Science and Technology, there was an extensive paper on the use of HFSS and CST MWS at THz frequencies, and the related issues and limitations. I am not working in this field myself, but the paper looked really useful and should answer your questions (how to model material properties at these frequencies etc.)
September 2012, Volume 2, Issue 5:
Defining Material Parameters in Commercial EM Solvers for Arbitrary Metal-based THz Structures
Elpida Episkopou, Stergios Papantonis, William J. Otter and Stepan Lucyszyn
Thank you, volker. That paper was very insightful.
Dear all
I think PlanarMetamaterials Idea is true, CST solves the problem in Time-Domain by using Finite Integration Technique but HFSS solves the problems in Frequency domain by Finite Element technique.
I should be noted that CST has added a frequency domain solver based on FEM and HFSS uses the TD-DGM to solve the time domain problem.
solving the dispersion media by frequency domain solver is easer than time domain solver. I think both of HFSS and CST can be used in THz regime.
Salam Agha Hamid
Hello Dear Hamid
I agree with you but these Much of things that you mentioned is completely True , I simulated Dual Dipole Antenna in Different Frequencies in THz Region with Both HFSS and CST Microwave and compared the results of these two EM Software but as Frequency goes up Dispersions as you said influence to Result in HFSS specially when i did simulation with HFSS Frequencies upper than 1THz and i mean two output parameters "return Loss" and also "Z11" but i didn't faced such these problems in CST Microwave...
You should not generalize your experience/experiment too much. Accuray with these EM tools heavily depends on the user's experience with the tool.
I didn't understand what you mean mr.Volker from Germany ...
I am not just posting in my Experience , i am posting according to the information from the papers which worked in THz Technology ...
But if you see the newest Papers i mean Transactions in IEEE # Springer & Elsevier ... you will see that most of the Simulations in THz Region are done based on CST Microwave EM Solver and their Result from Simulations are Validated by lots of Professors and Masters and referees ...
By the way , Thanks for the Transaction paper you introduced in above posts , it confirmed the better abilities of CST Vs. HFSS in Higher Frequencies.
HFSS works with THz-frequencies. As PlanarMetamaterials already said, it solves Maxwell's equations, which are valid here.
However, you have to consider (at least) two critical aspects:
The materials in HFSS are usually defined for 10GHz. If you do simulations with gold, silicon, etc. you have to add new materials to the materials database. From my experience, retrieving material properties is the most challenging part in setting up a THz-simulation.
The other point which may lead to simulation problems is the "model unit". The basis unit, used by HFSS, can be chosen from Modeler->Units. Try setting it to "um" or "nm".
We successfully simulated FSS around 300GHz, 1THz and 222THz and propagation in dielectrics up to 2.5THz. The simulation agreed with experiments quite nice.
To cd79,
I am simulating a gold SRR under 1.1 thz frequency using silicon substrate in HFSS, so I was wondering if you know the properties of gold and silicon we should use for the simulation since under thz frequency the properties change.
Thanks,
Chao
You can calculate the complex permittivity by the Drude Model. See formulas and references in my doc-thesis (in English): http://dokumentix.ub.uni-siegen.de/o.../pdf/debus.pdf