for your light reading enjoyment...
an excellent collection of papers to have laying around for reference

"Transmission Line Design Handbook" by Brian C.
Wadell


OPAMP Technical Books
1033 North Sycamore Avenue
Los Angeles, CA 90038

Phone (213) 464-4322
      (800) 468-4322

It's cost US$70.00, with a Visa and about $5.00 extra it appears on
your door step in two days.

cheers,
dwight

At 11:56 AM 5/24/96, [log in to unmask] wrote:
>     Yahhhh. High Speed Digital. Some sort of parallel processor thing that
>     runs at a Ghz. He wants to do the isolated Coaxial thing without
>     coplanar waveguide. He wants to produce a ground via barrier that
>     separates digital from control. (Probably on advanced <cleaner than
>     normal> materials)
>     Groovster
>
>
>______________________________ Reply Separator
>_________________________________
>Subject: Re: FAB: RFI/EMI Vias
>Author:  [log in to unmask] at SMTPLINK-HADCO
>Date:    5/23/96 7:44 PM
>
>
>
>          Groove man,
>
>          I would first ask: Does the customer want controlled
>          impedences on the board?  (I'm assuming they do...)
>
>          Doug
>
>
>______________________________ Reply Separator
>_________________________________
>Subject: FAB: RFI/EMI Vias
>Author:  [log in to unmask] at internet-mail
>Date:    5/23/96 5:46 PM
>
>
>
>        I have a customer who has asked me if I know about shielding vias.
>     I don't know much about these. All I know is that the size of the PTH
>     and the distance apart are based, somehow, on what frequency the
>     logic (PCB) is operating at. (Yessss?)
>
>        Now I don't have IEEE text books anywhere near this facility.
>     I'm a simple fabricator. Can someone who's savvy with RF <or even
>     Microwave> design give me some pointers to what kind of formulas are
>     used to determine this shield via barrier technique.
>
>
>     Thanks in advance for any and all replies.
>
>     Groovy
>
>