I have the same problem at my house, the router
is at the far end from the TV room where my laptop
usually is.
I tried this experiment, and
was surprised that it did little to improve the
WLAN signal strength!
I taped a 2.45 GHz
patch antenna to one of the three router antennas,
ran 75 ohm cable tv type coax the 200' to the TV
room, and had another patch antenna pointed at my
laptop, from 2' away.
It helped a little
bit, but not enough to make the installation permanent.
I was expecting a "excellent" signal, but it was
still "very weak".
Now, maybe if I got some
low loss foam dielectric 3 GHz cable, and if I actually
spliced into one of the router cables leading up
to the antenna, things would have been better. But
my conclusion, there is little I could do PASSIVELY
to make the signal much stronger.
There are
WLAN repeaters you can buy that actively intercept
the signals, boost them, and retransmit. Not all
routers will work well with such repeaters, so you
have to investigate. Also, if you have an external
antenna jack on your laptop, it would be an easy
thing to aim a high gain antenna in the "right"
direction to improve your signal.
It really
helps to move your wireless router around a little.
Perhaps moving it a couple feet from its current
position will have a big improvement.
Other
than that, good luck!!!
