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Design >> RF Design >> ground plane partial inductance
https://designers-guide.org/forum/YaBB.pl?num=1350399845

Message started by aaron_do on Oct 16^th, 2012, 8:04am

Title: ground plane partial inductance
Post by aaron_do on Oct 16^th, 2012, 8:04am

Hi all,

does anybody have a ball-park estimate of the partial inductance between two points on a ground plane?

thanks,
Aaron

Title: Re: ground plane partial inductance
Post by raja.cedt on Oct 16^th, 2012, 10:42am

hello,
it is very difficult to ans up to me, it is strongly depends on which is ground plane and how far those two points.

Thanks,
Raj.

Title: Re: ground plane partial inductance
Post by aaron_do on Oct 16^th, 2012, 8:29pm

I figure it depends on the size of the ground plane and the distance between the points. So there is no rule of thumb?

thanks,
Aaron

Title: Re: ground plane partial inductance
Post by RFICDUDE on Oct 17^th, 2012, 3:38am

One paper says the inductance from one point to another on a perfect conductor is

Lg = ( μ × l ) / ( 2π )

where μ is the permeability.

I'm not sure how or if this changes when there are multiple points.

Usually I'm dependent on looking at quasi-static EM solutions that produce LRC results or try to analyze S-parameter results of EM solutions to extract the distributed inductance between multiple points (grounds). But I've never looked for a trend or compared analytical solutions like the one above.

Title: Re: ground plane partial inductance
Post by aaron_do on Oct 17^th, 2012, 4:23am

Thanks, but what is 'n' in the equation? I guess I will try using an EM simulation.

regards,
Aaron

Title: Re: ground plane partial inductance
Post by RFICDUDE on Oct 17^th, 2012, 6:23am

It is PI.

This might be a good problem for FastHenry.
There is a freeware PC version from FastFieldSolvers.