Neato. I've seen permeable flex sheets and stuff before, but usually with lower mu, only useful into the gigs. It's not obvious, from the data they provide, how much attenuation you'd get at <100MHz in a given situation; despite the moderate permeability and permittivity, the thickness is quite low, so it's quite easy for stuff to get through. As far as near fields go, it probably works better on higher impedance (electrostatic) signals, due to the conductive layer and higher permittivity, and not so well on low impedance (electromagnetic) signals, which will tend to penetrate, or even saturate the material (if we're talking power conversion level fields). So regarding applications, you'd probably be looking for this sort of stuff around sensitive analog, digital, wideband and RF circuitry, and maybe to help take a few dB off a not-quite-compliant product (of any sort: power, computing, mobile, RF, etc.). It's probably quite handy inside molded plastic cases, which you'd have to weigh against other coatings or options (conductive paint, metallization).
If you need that sort of shielding for *powerful* magnetic fields, ferrite slabs are the way to go. FYI, you can get plates used for planar cores, and plates or disks used for spot shielding (I think the largest and thinnest such product I've seen is 2 x 2 x 0.1" from.. Laird?).
I've had situations where -- the EMI isn't even the biggest concern, the cabinet itself is actually getting too hot! Fields this intense can't even be stopped by solid copper shielding: it still gets too hot. Let alone EMI gasketing or spring stock, which get *really* hot. But, put some ferrite around the offending coil and it stays ice cold.
Tim
Home
Help
Search
Login
Register
