[SI-LIST] Re: EMI simulation tools at PCB level

  • From: "Charles Grasso" <cgrassosprint1@xxxxxxxxxxxxx>
  • To: <Chris.Cheng@xxxxxxxxxxxx>, <zhang_kun@xxxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
  • Date: Thu, 2 Dec 2004 22:31:01 -0800

Chris - It would be *much* easier for you to contact some experienced EMC
engineers - the phenomena you describe are understandabe and explainable.

-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Chris Cheng
Sent: Thursday, December 02, 2004 5:13 PM
To: 'zhang_kun@xxxxxxxxxx'; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: EMI simulation tools at PCB level


I am sure the consumer product guys will laugh at my stupidity but I can
never design a PCB that will pass FCC B without a large metal cage chassis.
I've always wanted to simulate why if I tighten the screw by one more turn
on my door and my EMI gaskets compressed a little harder and the signature
changed by 10 db.  Or if I hang the cable this way or that way the signature
changed by a few db. What I am trying to say is while EMI from PCB may be
the source, the enclosure/environment the PCB is in seems to have a bigger
impact on whether you are passing FCC than the PCB itself. Granted this is
just from an incompetent designer like me who cannot ship an absolute clean
PCB that can be wrapped in a plastic bag and passing FCC. Any simulation
tools that can help me ?

ps Is there any way I can receive messages from the list from outside the US
without these =2 =22 ? I know the US or English language is not the center
of the Universe so I appolgize in advanced.

-----Original Message-----
From: zhangkun 29902 [mailto:zhang_kun@xxxxxxxxxx]
Sent: Thursday, December 02, 2004 4:20 PM
To: si-list@xxxxxxxxxxxxx; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] EMI simulation tools at PCB level


Dear all

How about the development about EMC simulation at PCB level=3F As to my e=
xperience=2C there is the following development=2E It is my understand ab=
out the development of EMI at PCB level=2E If there is anything wrong=2C =
please give me some advice=2E

1=2EPaul proposed that common mode current is the main source of far fiel=
d EMI in =22A Comparison of the Contribution of Common-Mode and Different=
ial-Mode Currents in Radiated Emissions=22=2E

Here the source of EMI is defined=2E


2=2EHorck et=2E proposed the transform between DM and CM by means of tran=
smission line in =22Common-Mode Currents Generated by Circuits on a PCB--=
Measurements and Transmission-Line Calculation=22=2E

Here transform between DM and CM is partly explained=2E


3=2ELeone proposed the radiation from the PCB edge in =22The Radiation of=
 a Rectangular Power-Bus Structure at Multiple Cavity-Mode Resonances=22=2E=


Here the radiation from the PCB edge because of CM current is solved=2E


4=2EGerman=2C et=2E proposed the effect of image plane in =22Effect of an=
 Image Plane on Printed Circuit Board Radiation=22=2E In the next year=2C=
 Hsu gave more explaination in =22The Validity of Image Plane Theory to P=
redict Printed Circuit Board Radiation=22=2E

Here the effect of image plane is solved=2E


5=2EHejase=2C et=2E proposed the radiataion effect of pigtail in =22Shiel=
ding Effectiveness of Pigtail Connections=22=2E Goenen also proposed =22A=
lthough the actual path of the cable determines its effectiveness to radi=
ate=2C an average
radiation resistance of the order of 100 to 150 ohm has been measured =5B=
13=5D over the frequency range 150 kHz=961 GHz=2E=22 in =22EMC workbench=3A=
 Testing methodology=2C module level testing and standardization=22=2E

Here the radiation effect of cable is solved=2E


6=2ESignal integrity simulation has been solved in 90=27s=2E Power gound =
plane pair modeling has been solved well=2E
I have proposed method based on transmission line to solve problem combin=
ed of SI and PI=2E The return current=2C common mode current=2C could be =
exactly solved in the method=2E

Here the source of EMI=2C SI and PI=2C is solved=2E


There are a lot of other good paper which are not present here=2E In one =
word=3A
   1=2EThe source of EMI=2C common mode current=2C is caught out=2E
   2=2EThree kinds of radiation structure are solved=2C power ground plan=
e and cable=2E I think another is the trace on external layer=2E
   3=2EThe original source of EMI=2C SI and PI=2C has been modeled well=2E=

Therefore=2C I think the EMC simulation could be applied=2E

All above is my understand about EMI simulation at PCB level=2E If there =
is anything wrong=2C please give me some advice=2E

Best Regards

Zhangkun
2004=2E12=2E3

------------------------------------------------------------------
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 FAQ wiki page is located at:
                http://si-list.org/wiki/wiki.pl?Si-List_FAQ

List technical documents are available at:
                http://www.si-list.org

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 FAQ wiki page is located at:
                http://si-list.org/wiki/wiki.pl?Si-List_FAQ

List technical documents are available at:
                http://www.si-list.org

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 FAQ wiki page is located at:
                http://si-list.org/wiki/wiki.pl?Si-List_FAQ

List technical documents are available at:
                http://www.si-list.org

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: