Microwave shielding - RF Cafe Forums

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Shafique
Post subject: Microwave shielding
Unread postPosted: Mon Apr 25, 2005 4:06 pm

Hi,

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?

Shafique

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TJ
Post subject:
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.

TJ

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Guest
Post subject:
Unread postPosted: Mon Apr 25, 2005 10:27 pm

Hello,

There 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.

Posted 11/12/2012