Post subject: RF Shielding Posted: Sat Mar
17, 2007 12:14 am
Joined: Tue Feb 27,
2007 6:16 am
Hello. Can anyone direct me to a manufacturer
of RF shields that will supply free samples?
anyone direct me to where I can find some literature on RF shielding?
Im particularly interested in learning whats the best practice,
i.e can I shield my reference oscillator and PLL together or will
one intefer with the other.... how I can avoid the need to provide
Posted: Fri Mar 23, 2007 6:59 pm
Mon Jun 27, 2005 2:02 pm
You can find many manufacturers by running a Google Search.
Here is an example to one:
can't avoid shielding if you design Oscillators and other frequency
sources. Usually the reference oscillator and the PLL should be
placed as close as possible to each other. If you have forward and
reverse links on the same PCB then you should shield each of them
to avoid coupling between the two which can produce feedback and
lead to oscillations.
The purpose of shielding is to prevent
radiation from propogating and to prevent coupling between adjacent
Post subject: Posted:
Mon Mar 26, 2007 5:38 am
Feb 17, 2006 12:07 pm
Location: London UK
Engineering Director of a well-known company for which I once worked
(as a very young green-horn) often maintained that "the cheapest
development equipment is a hacksaw", by which he meant "cut the
lid off someone else's box and learn from what you see inside".
Whilst I would not dream of advocating plagiarism, or still less,
copyright infringement, you could learn more about screening by
looking into existing products that use PLL-VCO circuits than by
reading up the theory.
Screening theory is notoriously difficult
from which to formulate strict rules. Even simple analytical situations
of say a cylinder of metal enclosing an oscillator requires several
types of Bessel Functions to derive the leakage field outside the
can. Oisch, my brain hurts already, thinking of the pages full of