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Impedance mismatch in quasistatic

Jean-Philippe Turmaud

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Hello everybody!

I need the help of people familiar with AC/DC and RF module. I am working with a 3D structure consisting of 2 pads, 100um*200um*0.2um, separated by a 1um slot line. The pad are shorted at one end (5-20um wide strip) and connected by 25um diameter cylinders from the top on the other end where I want to put my terminal and ground.

I am working at 10 GHz so, because the electrical size of my system is around 1/100, i used the AC DC module, magnetic and electrical field. this pattern is laid on top of a 0.5 SiO2 layer and 100um Si layer.

My question:
Does Comsol in these conditions take into account the reflection due to impedance mismatches when calculating the current and the fields in the slotline?

I am not so sure what i should expect here because the system is small and the usual calculation of slotline impedance say that it depends on the width of the slotline, and here the admittance yielded does not depends much on it.

What do you think?

Thanks for your help!

2 Replies Last Post 19 avr. 2013, 07:56 UTC−4
Edgar J. Kaiser Certified Consultant

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Posted: 1 decade ago 19 avr. 2013, 07:39 UTC−4
Jean-Philippe,

in the AC/DC approximation everything happens instantaneously in your structure. So you won't see any transmission line effects. If you want to see that you must use RF.
But as you stated your structure is small enough for AC/DC.

Cheers
Edgar

--
Edgar J. Kaiser
www.emphys.com
Jean-Philippe, in the AC/DC approximation everything happens instantaneously in your structure. So you won't see any transmission line effects. If you want to see that you must use RF. But as you stated your structure is small enough for AC/DC. Cheers Edgar -- Edgar J. Kaiser http://www.emphys.com

Jean-Philippe Turmaud

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Posted: 1 decade ago 19 avr. 2013, 07:56 UTC−4
Edgar,

Ok I see thanks! I will try to investigate more in the RF module, and come back if I have more questions.
So great that you answered so quickly!
Edgar, Ok I see thanks! I will try to investigate more in the RF module, and come back if I have more questions. So great that you answered so quickly!

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