On Tue, 15 Sep 1998, Gary Boccoleri wrote:
> Can anyone help me with information on guard banding. I'm talking about
> shielding a trace by circling it with a ground trace. This has come up
> as a way to solve all of our EMI problems. I'm of the opinion that the
> additional spacing it requires is what helps to prevent crosstalk and
> the ground traces just take up space.
>
> If anyone has any opinions on this (pro or con) or can point me at some
> resources on the subject I would appreciate it.

>
> ##############################################################
> Gary Boccoleri                  Lucent Technologies
> 510-737-2195                            Remote Access Business Unit
> 510-737-2110 FAX                        4464 Willow Road
> [log in to unmask]                    Pleasanton,  CA 94588-8519
> ##############################################################
>

Gary,

You may wish to have a look at the book "Printed Circuit Board Design
Techniques for EMC Compliance" by Mark I. Montrose, IEEE press 1996. He
has 5 & a half pages on "guard/shunt traces" (Section 4.11, pg 94). He
essentially says that they are useful in 2 layer boards & essentially it
is the extra space that helps you in microstripline or stripline boards.
He says "Guard traces perform best on one- and two-layer boards (i.e.
those without a power or ground plane)."


--
Dom Bragge    (VK2YAK)      ___  _____  JNA Telecommunications Limited
Senior PWB Designer(R&D)__ / / |/ / _ | 16 Smith St  Chatswood  NSW 2067
Tel: (+61 2) 9935 5792 / // /    / __ | AUSTRALIA    [log in to unmask]
Fax: (+61 2) 9417 3862 \___/_/|_/_/ |_|    E-:-I   http://www.jna.com.au

       "In the process of being swallowed up by Lucent"

################################################################
DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE DesignerCouncil <your full name>
To unsubscribe:   SIGNOFF DesignerCouncil 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################