[SI-LIST] Re: plane RLGC Debye model
- From: "Istvan Nagy" <buenos@xxxxxxxxxxx>
- To: <shlepnev@xxxxxxxxxxxxx>, "'steve weir'" <weirsi@xxxxxxxxxx>
- Date: Sat, 15 Nov 2008 22:12:23 -0000
hi
thanks, this answers my question, but opens a new one.
"fit it with 3-4 real poles evenly distributed over you frequency band to
get rational approximation form"
-probably this would be the most difficoult part for me, i think. at least i
have no idea how to do it (theory, c program).
but probably its not a signal/power integrity problem already, but
mathematics.
on chapter 7, you mean chapter 4.2.1.6, figure 4.6d ? ok, it doesnt matter.
regards,
Istvan
----- Original Message -----
From: "Yuriy Shlepnev" <shlepnev@xxxxxxxxxxxxx>
To: "'Istvan Nagy'" <buenos@xxxxxxxxxxx>; "'steve weir'" <weirsi@xxxxxxxxxx>
Cc: <si-list@xxxxxxxxxxxxx>
Sent: Saturday, November 15, 2008 7:48 PM
Subject: RE: [SI-LIST] Re: plane RLGC Debye model
> Istvan,
>
> If you have dielectric constant value at 1 MHz, dielectric constant at 20
> GHz may be about 10% smaller for a composite PCB material (as observed in
> multiple experiments). It may be not important for practical PDN design as
> Steve mentioned and simple 1-frequency approximation for G and C may work
> just fine. The same is valid for R and L. Though, in case of very closely
> spaces planes (with less than 5 mils distance), the effect of internal
> inductance of the metal planes in combination with the dielectric
> dispersion
> can cause significant shifts of resonances even at lower frequencies
> important for PDN design.
> If you want to build the lattice-type equivalent circuit model valid over
> 3-4 decades in frequency and accounting for frequency variations of
> dielectric constant and internal plane inductance, it can be done with the
> broadband transmission plane model (see my paper "Transmission plane
> models
> for parallel-plane power distribution system and signal integrity
> analysis"
> in proceedings of 22-nd ACES symposium, 2006, p. 382-389, also available
> at
> http://www.shlepnev.com/Publications/ACES2006c.pdf). The model is
> validated
> with experiments in I. Novak, J. Miller Frequency-domain characterization
> of
> power distribution networks - Artech House, 2007, chapter 7 and in J.
> Miller, G. Blando, B. Williams, I. Novak "Impact of PCB Laminate
> Parameters
> on Suppressing Modal Resonances" - DesignCon2008.
>
> Here are possible steps to build broad-band SPICE model for PDN:
> 1) Use equation (3) from the cited ACES paper for frequency-dependent
> admittance per square Ys and fit it with 3-4 real poles evenly distributed
> over you frequency band to get rational approximation form (9)
> 2) Use equation (11) for sheet impedance of the plane pair Zs and fit it
> with 3-4 real poles to get the rational approximation form (12)
> 3) Define cell size dx and dy for your equivalent lattice model
> 4) Compute admittance of one sell as Ys*dx*dy - the rational approximation
> from step 1 immediately gives you the second Foster form of GC or RC
> network
> for the cell node
> 5) Compute impedance of one sell as Zs*dx/dy for x-axis and as Zs*dy/dx
> for
> y-axis - the rational approximation from step 2 immediately gives you the
> second Foster form of RL network for the x and y branches of your cell
> 6) Combine cells into a 2D equivalent circuit of the plane pair
>
> Note that the final 2D model is similar to a lumped broad-band model for a
> transmission line.
>
> Best regards,
> Yuriy Shlepnev
> www.simberian.com
>
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> On
> Behalf Of Istvan Nagy
> Sent: Saturday, November 15, 2008 4:45 AM
> To: steve weir
> Cc: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] Re: plane RLGC Debye model
>
> hi
>
> the only thing what i have is the dielectric thickness, and Er@1MHz, as
> usual. i normally dont haave measurement data.
> the simple RLGC models dont take the frequency-dependeny of the Er into
> account, skin effect,...
> these can be described by simple equations, but how to kame a lumped model
> based on equations containing E^x... and similar things.
> at least these 2 effects should be included.
> Er(f)=Er(f0)*(jf/f0)^(-0.006366) this gives a frequency dependency for C
> and G
> R is dependent on f because of the skin effect.
> somehow L is also dependent on frequency?
>
> because it is for a unit-cell model, it shouldnt need more then very few
> parameters, like dielectric thickness, Er(f0), f, cell size.
>
> Istvan
>
> ----- Original Message -----
> From: "steve weir" <weirsi@xxxxxxxxxx>
> To: "Istvan Nagy" <buenos@xxxxxxxxxxx>
> Cc: <si-list@xxxxxxxxxxxxx>
> Sent: Saturday, November 15, 2008 12:29 PM
> Subject: [SI-LIST] Re: plane RLGC Debye model
>
>
>> Istvan what data do you have? Do you have measurements from material
>> samples?
>>
>> For most power work, it is sufficient to use a single value for tangent
>> loss. If you get the other parameters correct, then the models will
>> tend to show slightly higher peak impedances at the modal resonances
>> than measurements out above 1GHz, but the difference is typically not
>> great.
>>
>> Steve.
>> Istvan Nagy wrote:
>>> hi
>>> how can i calculate the Ri, Li, Gi, Ci parameters for a frequency
>>> dependent unit-cell Debye RLGC model for a power/gnd plane pair? 1st
>>> order or up to 3rd order Debye model would be good.
>>> are there any equations?
>>> (Debye models introduce additional RL and GC elements into the 4 element
>>> original RLGC model to reflect the frequency-dependency, and with
>>> staying
>
>>> with basic circuit elements, suitable for spice)
>>>
>>> i would like to make frequency dependednt spice 3f5 models (not
>>> w-element
>
>>> model, since its not compatible with most of the spices) from arbitrary
>>> power planes, with lumped-element grid.
>>> I found application notes where in the examples they just shown the
>>> calculated values, without describing the calculation.
>>>
>>> regards,
>>> Istvan Nagy
>>> ------------------------------------------------------------------
>>> 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 technical documents are available at:
>>> http://www.si-list.net
>>>
>>> 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
>>>
>>>
>>>
>>>
>>
>>
>> --
>> Steve Weir
>> Teraspeed Consulting Group LLC
>> 121 North River Drive
>> Narragansett, RI 02882
>>
>> California office
>> (866) 675-4630 Business
>> (707) 780-1951 Fax
>>
>> Main office
>> (401) 284-1827 Business
>> (401) 284-1840 Fax
>>
>> Oregon office
>> (503) 430-1065 Business
>> (503) 430-1285 Fax
>>
>> http://www.teraspeed.com
>> This e-mail contains proprietary and confidential intellectual property
>> of
>
>> Teraspeed Consulting Group LLC
>>
> ----------------------------------------------------------------------------
> --------------------------
>> Teraspeed(R) is the registered service mark of Teraspeed Consulting Group
>> LLC
>>
>> ------------------------------------------------------------------
>> 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 technical documents are available at:
>> http://www.si-list.net
>>
>> 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 technical documents are available at:
> http://www.si-list.net
>
> 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 technical documents are available at:
http://www.si-list.net
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:
