Post subject: Microwave shielding
Mon Apr 25, 2005 4:06 pm
If I'm not concerned
about interference or EMI, should I conceal my Microwave circuit,
(operating at 2.4GHz) in a metal box that's grounded? The circuits
are MMIC based VCOs and amplifiers. What would be the disadvantage
of not doing so?
Unread postPosted: Mon Apr 25, 2005 4:30 pm
The only reason you might want to do a shield in your case
is if your circuit might interfere with something else in the area.
Of course, there is the FCC Part 15 unintentional radiator thing
wou'll have to worry about if you plan to commercialize the design.
postPosted: Mon Apr 25, 2005 10:27 pm
is no disadvantage of shielding your circuits. This is a very common
practice in RF design and PCB layout. I am using a double shielding
option, namely shielding cans for the first prototype (There are
customes sizes of shielding cans) and you can design the size of
each module in your PCB to match to the size of the can. And for
the final revision that will go to production there are holes that
will be used to tighten a cover with screws around the PCB layout.
This cover will have spaces inside that surround each module and
isolate it from the others. This method gives at least 70dB of isolation
between the different parts of the PCB. Of course that for better
isolation you can use gasket of shielding material as often done
to seal possible scratches.