[SI-LIST] Re: Finding Er (Permitivity)
- From: Tim Hochberg <tim.hochberg@xxxxxxxx>
- To: cclewell@xxxxxxxxxxxxxx,"'Peterson, James F (FL51)'" <james.f.peterson@xxxxxxxxxxxxx>,si-list@xxxxxxxxxxxxx
- Date: Fri, 18 Jul 2003 07:05:49 -0700
Another issue is that, for microstrip, this is going to give you the
effective dielectric constant, not the actual dielectric constant. If
you can use stripline instead, this won't be a problem, otherewise your
going to need to try to recover the dielectric constant from the
effective dielectric constant. This will be a little bit approximate
since the effective dielectric constant is frequency dependant. However,
the dependence is week, and there are effective dielectric calculators
floating around on the web, so you should be OK.
Regards,
Tim
Clewell, Craig wrote:
>Jim,
>
>I've got a big bat <grin>.
>
>You are correct...sorry about that.
>
>Thanks for the clarification.
>
>Craig
>
>-----Original Message-----
>From: Peterson, James F (FL51) [mailto:james.f.peterson@xxxxxxxxxxxxx]
>Sent: Friday, July 18, 2003 9:25 AM
>To: cclewell@xxxxxxxxxxxxxx; 'kamal_elx@xxxxxxxxxxx'
>Cc: si-list@xxxxxxxxxxxxx
>Subject: RE: [SI-LIST] Re: Finding Er (Permitivity)
>
>
>craig,
>
>it might be a pretty big ballpark!!
>you would have to square the equation to get Er.
>
>Vp(m/s)= 3e8(m/s)/sqrt(Er)
>so
>Er = (3e8(m/s)/Vp(m/s))^2
>
>regards,
>Jim
>
>-----Original Message-----
>From: Clewell, Craig [ mailto:cclewell@xxxxxxxxxxxxxx
><mailto:cclewell@xxxxxxxxxxxxxx> ]
>Sent: Friday, July 18, 2003 8:40 AM
>To: 'kamal_elx@xxxxxxxxxxx'
>Cc: si-list@xxxxxxxxxxxxx
>Subject: [SI-LIST] Re: Finding Er (Permitivity)
>
>
>Venu,
>
>If the board is a Microstrip you can do a quick measurement of the delay and
>
>use this value to calculate the E'r.
>
>Use E'r = 3e8(m/s) / vp(m/s)
>
>where vp = propagation velocity = inverse of the delay. This should get you
>
>in the ballpark
>
>Regards,
>
>Craig
>
>-----Original Message-----
>From: Kamal EC [ mailto:kamal_elx@xxxxxxxxxxx <mailto:kamal_elx@xxxxxxxxxxx>
>]
>Sent: Friday, July 18, 2003 7:25 AM
>To: si-list@xxxxxxxxxxxxx
>Subject: [SI-LIST] Finding Er (Permitivity)
>
>
>Hello Everybody,
>
>I am having a PCB Board for which I want to calculate the Permitivity. I
>don't know what material is used for the pcb.
>I don't have any details of the board, except the fabricated board.
>
>Is there any method by which i can calculate.
>
>Regards,
>Venu
>
>_________________________________________________________________
>It's new, it's here! It's full of fun!
>http://server1.msn.co.in/sp03/messengerpromo/index.asp
><http://server1.msn.co.in/sp03/messengerpromo/index.asp> MSN Messenger V6.0
>
>
>------------------------------------------------------------------
>To unsubscribe from si-list:
>si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
>or to administer your membership from a web page, go to:
>//www.freelists.org/webpage/si-list
><//www.freelists.org/webpage/si-list>
>
>For help:
>si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>List archives are viewable at:
> //www.freelists.org/archives/si-list
><//www.freelists.org/archives/si-list>
>or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
><http://groups.yahoo.com/group/si-list/messages>
>Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu <http://www.qsl.net/wb6tpu>
>
>------------------------------------------------------------------
>To unsubscribe from si-list:
>si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
>or to administer your membership from a web page, go to:
>//www.freelists.org/webpage/si-list
><//www.freelists.org/webpage/si-list>
>
>For help:
>si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>List archives are viewable at:
> //www.freelists.org/archives/si-list
><//www.freelists.org/archives/si-list>
>or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
><http://groups.yahoo.com/group/si-list/messages>
>Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu <http://www.qsl.net/wb6tpu>
>
>
>
>
>------------------------------------------------------------------
>To unsubscribe from si-list:
>si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
>or to administer your membership from a web page, go to:
>//www.freelists.org/webpage/si-list
>
>For help:
>si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>List archives are viewable at:
> //www.freelists.org/archives/si-list
>or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
>Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
>
>
>
>
>
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
