RF circuit cases and box
Is there any case design files in AUtoCAD?
What is the material of RF cases?
Aluminium! And most of the time the design is custom-made and adopted from the RF print layout.
Aluminum in air will oxside and its surface prevent good conductivity.
For applications where case is grounded and should be connected to RF circuit pcb ground and there are N-type connectors at input/output and must be grounded at case,how we can use this metal?
Can we use IRON?
which is better? Aluminum or Iron?
Bets regards
http://chemandy.com/products/page1/f...e-prod01-1.asp
I don't think the aluminum oxide thickness is a big problem in a normal environment. Even at 100 GHz the sking depth is 0.26 um, while aluminum oxide thickness is maybe 0.05 um. Now in a salty environment it could be a big problem. Most mmw waveguide is gold plated but standard uw waveguide is not. Now if you want to make good electrical contact to aluminum you can alodine.
You can gold plate the aluminum but you need a nickel barrier, which means getting the gold thick enough to prevent the RF current from flowing in the nickle.
i think tungstun can be used for RF cases.
what about IRON?
Can we use IRON in RF cases?
(up to 3GHZ)
madengr:
what is alodine? can you explain more?
Can we anodize aluminum ? Is anodized aluminum ok for RF cases?
Well, with the proper coating iron could be used. The problem is corrosion. If you mount a microstrip circuit to the floor of an iron housing, and you have coaxial connectors going out of the side, you need the iron housing to make excellent contact to the bottom of the microstrip in the vicinity of the connector, and to the underside of the connector too. Otherwise, you would not have a good ground connection between the connector and the microstrip backside.
Something like nickle plate over iron/steel would work. Steel is preferrable to iron, since you will want to drill and tap small holes.
Is steel drilling hard?(for 2.5mm holes)
Can I use normal aluminum for (f <= 3GHZ) RF cases with panel mounted N ,SMA connectors?Is there probelm with AL oxside surface in normal environment?
Sources for boxes include Digikey and Mouser. Shielded boxes with higher isolation (more expensive) are available from Laird Technologise and Leader Tech. There are others.
Is this kit too expensive?
http://www.fotofab.com/pdf/Proto_Kit.pdf
thanks to all,ready cases are not good for may needs ,I want to design and make my own cases.
please send the answers to my last Q.