Superconducting Simulations in HFSS

[Firkin]

Hi,

I was wondering if anybody has resources or examples of how to simulate superconducting circuits in HFSS. Anything specifically dealing with modeling of superconducting resonators would also be much appreciated.

Thanks for the continued support!

 

[Phytech]

Can you just use an ideal conductor for the simulation?

 

[Firkin]

I am using that that, but I am wondering if there is anything else. I should be getting an extremely high Q-factor for my simulations, but have not had any luck so far.

 

[Phytech]

I am using that that, but I am wondering if there is anything else. I should be getting an extremely high Q-factor for my simulations, but have not had any luck so far.

Superconductor also has loss at microwave frequency, which is represented by surface resistance. From this point of view, it is the same as ideal conductor. The only difference between a superconductor and an ideal conductor is related to magnetic field.

By the way, what kind of Q factor did you get?

 

[ferdows]

hi
u should find a superconductor formula or tables of these material and then design this material in hfss

 

[Firkin]

Thanks for the replies. The highest Q I have been able to simulate is around 330. I was expecting much, much larger values.

 

[Phytech]

Thanks for the replies. The highest Q I have been able to simulate is around 330. I was expecting much, much larger values.

How do you simulate the Q? Maybe the Q you obtained is only loaded Q, which is quite different from unloaded Q of the resonator. Without knowing how you obtained your Q, I cannot make further comments on your results.

 

[Firkin]

To calculate the Q, I am just dividing the resonant frequency over the bandwidth from the S21 parameters. According to some papers on the subject, it is possible to get a loaded Q of well over 10,000.

---------- Post added at 10:11 ---------- Previous post was at 10:02 ----------

hi
u should find a superconductor formula or tables of these material and then design this material in hfss

Thanks ferdows. Would you know of any literature that would contain this information?

 

[Phytech]

How much insertion loss you got for your resonant peak? It looks to me you are calculating the loaded Q of the resonator and you misunderstood this Q with the resonator unloaded Q.

 

[ferdows]

hi
pls see this i think u can find material structure and search it parameters and add to hfss
Superconductivity - Wikipedia, the free encyclopedia

 

[volker_muehlhaus]

Superconductor also has loss at microwave frequency, which is represented by surface resistance. From this point of view, it is the same as ideal conductor.

Don't forget the surface inductance of a superconductor. This has a different frequency dependence from normal conductors (skin depth δ vs. London penetration depth λ).

Sonnet is widely used for EM analysis of superconducting deviced. It does have a metal definition for superconductors.

http://www.alma.nrao.edu/memos/html-memos/alma245/memo245.pdf

 

[Firkin]

Don't forget the surface inductance of a superconductor. This has a different frequency dependence from normal conductors (skin depth δ vs. London penetration depth λ).

Sonnet is widely used for EM analysis of superconducting deviced. It does have a metal definition for superconductors.

http://www.alma.nrao.edu/memos/html-memos/alma245/memo245.pdf

Thank you very much for your reply volker. Does Sonnet also illustrate the vector field lines? That is one of the reasons I chose HFSS, but if it makes more sense to model this in Sonnet I would be willing to learn.

 

[Phytech]

Don't forget the surface inductance of a superconductor. This has a different frequency dependence from normal conductors (skin depth δ vs. London penetration depth λ).

Sonnet is widely used for EM analysis of superconducting deviced. It does have a metal definition for superconductors.

http://www.alma.nrao.edu/memos/html-memos/alma245/memo245.pdf

True. The dependence on frequency for an ideal conductor is square root, while for superconductor it is square.

 

[volker_muehlhaus]

Does Sonnet also illustrate the vector field lines?

Sonnet can visualize the surface current density, but not E/H fields.

 

[Firkin]

Alright, I will continue to try to get my model in HFSS working then. Thank you very much for your help.

 

[ferdows]

hi fir kin i suggest u forget HFSS for this work and better u define in matlab or FEMLAB i think FEMLAB is best for this work

 

[Firkin]

Thanks ferdows. I don't know if I have access to FEMLAB, but I will look into it.

 

[ferdows]

hi firkin
i usually advise other to use HFSS for simulation but hfss or CST and antenna software have problem with some conditions for this situation i suggested FEMLAB which a software of matlab with structure of FEM
i dont have vast knowledge in superconductors but when read some paper after your question i found this material related to heat too , so i HFSS u cant design heat but in femlab u can design code for them

 

[volker_muehlhaus]

cant design heat but in femlab u can

I have worked in that field. For superconducting filters, thermal analysis is not needed.

It would be nice if people who post here have at least some idea about the topic....

 

[ferdows]

hi
i said i have no knowledge in this field but i added that if need thermal solution its impossible in hfss and in femlab if u have knowledge pls give to if dont like give u science pls dont say u idea