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Other CAD Tools >> Physical Verification, Extraction and Analysis >> Simulating a high Q MKID in Sonnet
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Message started by lefebre on Dec 12^th, 2016, 7:11pm

Title: Simulating a high Q MKID in Sonnet
Post by lefebre on Dec 12^th, 2016, 7:11pm

Hello,

So I need some help. I am currently designing superconducting MKID resonators in Sonnet but I cannot get a high Q.
Ideally the MKID should resonant at 400MHz and have a Q greater than 10^6. I can get a half wave resonator to resonate at 400 MHz but the Q is always smaller than 1000.
Can anyone that is familiar with this kind of thing help me out?
I have set all losses (resistance, tangent loss) to zero and am using a surface inductance of 50 pH/Sq to simulate TiN.
The MKID is coupled to a two port feedline. I am using the graph of S21 to calculate Q by dividing the resonant frequency by the bandwidth. No matter what I do it seems like I cannot get a bandwidth smaller than .5 MHz.
Anyone have any tips or advice?

Thanks

Title: Re: Simulating a high Q MKID in Sonnet
Post by Maks on Apr 14^th, 2017, 4:59pm

Well, superconductors is not the kind of system that the developers of EM simulation tools have in mind, usually.

It may well be the case that the simulation tool will fail if resistivity of some layers is set to zero. To avoid numerical problems, the tool may add some small resistivity value, that would not affect any results for realistic metals (say Cu or Al at room temperature or so), but would be absolutely detrimental for the simulation accuracy of very low resistive (such as superconductive) systems.

Check with the documentation or with Sonnet support.

Max