RF Absorption / Refraction for Fibreglass - the hard material (well, a smoke curtain)

[marketdrayton]

Q1 for me here 🙂

Something I have never come across before, but a query I need to look at.

I have designed a wireless solution at height and the antennas in a specific location are blocked from LOS by what is a ceiling mounted smoke curtain approx 2m long, at a height of 8-10m A.F.L. Below the curtain is open space. The curtain is weighted down with a steel rod.

The curtain is made from flexible sheet fibreglass I am advised, but there are no propagation values for this material that I can see. Only rockwool / foil backed insulation materials typically used in domestic properties and commercial offices.

Anyone like to put a figure on this, or even by the very name, confirm it refracts the signal. The solution is for RTLS.

Thanks. Look fwd to the responses.

[Bruce]

I’ve never come across such a curtain in a building before, but a quick Google revealed this, https://www.strongwell.com/wp-content/uploads/2013/10/why-fiberglass-flyer.pdf, which suggests it’s RF transparent.

I’d suggest that it’s going to have very little impact based on this, but to be sure you’d want to do some testing. Obviously that’s going to be a tough one given the environment/location.

[marketdrayton]

@Bruce good suggestion. We obviously use GRP (Glass Reinforced Polyester - IIRC) as IP rated enclosures, and although most times we would attach a designated antennas, many times it is a cheaper way of converting an internal AP to external.

These have little to no impact, so I think your observation may well be accurate. This material is a heavy material, so may / may not include different construction but this has made me more confident of it certainly allowing the RF to propagate, whereas 10 mins or so ago I was more leaning toward the opposite.

Thank you.

[jmoake]

We have also used GRP and plastic boxes for indoor APs to be used outdoors and not seen any problems with signal strength.  tested with the door open and closed without a difference in signal strength. 

if your curtain is large and heavy,  there may be a metal mesh inside the layers for strength that you may have to consider.  if it is there, depending on the mesh size, it may or may not have an effect.  You know, just to muddy the waters