Shielding on 2.4GHz

Hi everyone,

 I am using FLEX2400 d'boards to transmit and receive 802.11b 

packets
with codes from bbn and gnuradio_example/python/digital. The problem is
the
d’board is always interferenced by some CISCO access pointed and other
wireless cards located right outside of my lab.

 I connect the usrp to my pc with a cable (-30db attenuator 

applied). I
hope it receives nothing but packets from my pc. But the d’board can
still
get packets from other wireless card. Then I put the m’b and d’b into
the
black enclosure. Packets still come in. And finally, I put everything
(m’b,
d’b, black box, attenuator) in my metal drower. Most packets are
shielded
out. Some still can be caputured and demodulated.%-|

 why is the d'b able to hear others even when I connect attenuators 

and
cable to its antenna?

 -DX


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DiX wrote:

black enclosure. Packets still come in. And finally, I put everything (m’b,
d’b, black box, attenuator) in my metal drower. Most packets are shielded
out. Some still can be caputured and demodulated.%-|

 why is the d'b able to hear others even when I connect attenuators and

cable to its antenna?

 -DX

It might pick it up on the 6V power cable.
You could try putting ferrite beads around the power cable to reduce
this.

greetings,
Martin

Martin D. wrote:

It might pick it up on the 6V power cable.
You could try putting ferrite beads around the power cable to reduce this.

greetings,
Martin

Thanks for your suggestion. I removed a ferrite bead from my USB cable
and
put it on the power cable. Tested it again. The interference was still
there.

I suspect the interference goes to the d’b directly, becasue when I use
the
enclosure and metal box to cover the d’b, the interference decreases
dramatically. But those cannot reduce the interference low enough for
our
test. Maybe we just need a M1A1 tank.

Best

-DX


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