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Design >> RF Design >> a layout question about the inductor
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Message started by baohulu on Aug 25^th, 2017, 3:17am

Title: a layout question about the inductor
Post by baohulu on Aug 25^th, 2017, 3:17am

hi, all
I have seen a inductor, its layout is in the attachment.
why the width of the inductor is narrower inside ? is there any benifit for this type ?

thanks

Title: Re: a layout question about the inductor
Post by cheap_salary on Aug 26^th, 2017, 3:33am

To keep area where magnetic flux is crossed.

Title: Re: a layout question about the inductor
Post by baohulu on Aug 27^th, 2017, 11:07pm

you say the outside has both the input and output influx, thus need large area, thus wider metal width ?
is there any paper describe this ?

thanks

Title: Re: a layout question about the inductor
Post by cheap_salary on Aug 28^th, 2017, 1:27am

baohulu wrote on Aug 27^th, 2017, 11:07pm:

you say the outside has both the input and output influx

What do you mean by input and output influx ?
Describe using correct terminologies.

Title: Re: a layout question about the inductor
Post by baohulu on Aug 28^th, 2017, 4:10am

what does the "magnetic flux cross" means ?
if we see the screen as a plane, the magnetic lines of flux inside the inductor has two direction, one is towards the screen, and the other is leaving the screen, you said "cross" means both the two direction magnetic flux exist ?

Title: Re: a layout question about the inductor
Post by cheap_salary on Aug 28^th, 2017, 5:31am

baohulu wrote on Aug 28^th, 2017, 4:10am:

what does the "magnetic flux cross" means ?

Consider simple solenoidal coil.
Expression of "magnetic flux cross" is used commonly there.

There is no input and output regarding flux.

baohulu wrote on Aug 27^th, 2017, 11:07pm:

is there any paper describe this ?

Too easy.
Simply consider situation if inner width is not narrow with keeping outer diameter.

Title: Re: a layout question about the inductor
Post by baohulu on Aug 28^th, 2017, 8:39pm

in the plane vertical to the inductor ring , the magnetic line can be described as "in" and "out" two direction , though the magnetic line is continuous all the time.

if the width of the inductor is opposite, the inside inductor ring width is wider than the outside ring width, the inductor can also hold the same area, or say, the same outer diameter, do you think the two type inductors have the same performance ?