Hi Frank!

Thank-you very much for taking the time to explain things for me, makes
things more understandable now...not easier to deal with (GRIN), but more
understandable.

-Steve Gregory-


> Steve,
> Bear with me while I try this.
>         First of all there is an issue in RF design that has priority over
> just about everything, that is the "return path". As a signal is sent down a
> RF pathway (components, transmission lines, etc.) there is an equivalent
> signal traveling the return path. If the return path is of a different
> length than the signal path then there is a degradation of the signal (this
> is a bad thing). So as RF goes the closer I get ground (my return path of
> choice) the better integrity I have for my RF signal.
>         Secondly, there is the issue of RF ground as a part of the RF magic
> (I think it is mostly the return path issue) having an effect on the
> electromagnetic fields surrounding the RF signal path. Any disruption in
> this field can cause integrity issues and performance failures.
>         Thirdly, there is the need to develop and market product rapidly in
> todays world that tends to make the extra XXX hours needed to refine a
> circuit enough to pull vias back impossible to get.
>         Lastly there is the RF factor. This is the fact that even the top RF
> guys will admit to "it's magic" sometimes.
> Even though as designers we hate to make the boards harder for you to
> assemble, we must make the circuit work. This means vias near lands, poor
> thermal relief around components (poor hell, usually none), and extremely
> tight component placements are all caused by the driving need to maintain
> the signal's integrity (so you can hear that cell call, static and all).
> Though as a designer I feel bad for what we do to guys like you, know you
> are appreciated for making us look good when the customer has a product that
> achieves spec.
> Hope it helps,
> FNK
>
> Frank N Kimmey, C.I.D.+
> Senior PCB Designer
> Powerwave Technologies
> PH. 916-941-3159
> Fax 916-941-3195
>