The facts about shielding Tents
As well as being a commercial supplier we also like to share our knowledge for people who want to know. We have put together unbiased fact sheets for each of the products we supply.
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An unbiased data sheet
The basis for the shielded walls is normally flexible conductive fabric.
The flexible shielded enclosure has sheets of conductive fabric stitched (sewn) together via normal or strengthened stitching methods, there are some double stitching machines that make stronger joins (seams)
Where the conductive fabric has to interface with a solid surface (floor/door/filter/panel) the normal method of causing electrical continuity is to press/ drive/trap the conductive fabric onto the mating conductive surface by clamping into position causing minimal DC resistance
There are a number of different flexible shielded enclosure types:
The shielding performance of the fabric claimed by the fabric manufacturer can be high, but, there is a great deal of difference between a small test jig (which they use) and a larger tent with doors, filters, panels etc
In terms of a finished flexible enclosure it would be optimistic to expect more than -60dB (or even as much as -60dB) and -50~55dB might be more realistic (depending on the system and manufacturer the finished enclosure could be lower than -50dB)
Some systems that use ordinary (non-conductive) Zips or Velcro are very low in performance as there is almost no RF continuity across such a joint and so act as slot antennas, remember, the laws of Faraday cage engineering principals always apply for any electromagnetic shielded enclosure.
