On Mon, 10 Nov 2003 23:08:49 +0000 (UTC), "Reg Edwards"
wrote:



A polarisation error of 45 degrees of a dipole results in only 3 dB smaller
signal. This is not noticed in areas of good signal strength where most
people live. Polarisation doesn't seem to bother mobile phone users very
much either.

It is necessary only that interfering signals and echos, if there are any,
are minimised. And that depends more on the direction from which waves are
received.
----
Reg.

Reg-

In the mobile radio world, where you do not generally have line of
sight propagation the polarization is best described as random, as it
arrives via multiple paths that change as the user moves or the
surroundings change. Hence, there is no preferred polarization
orientation for the mobile handset.

In fact, you'll find polarization diversity receiving antennas at base
stations, with either switched receivers or maximal ratio combining,
using two receivers, one fed with a vertically polarized antenna and
one with a co-located horizontally polarized antenna. Usually this
works pretty well, just a bit inferior to space diversity, but it's
quite a bit cheaper for the operator, as the V and H antennas can be
put into the same radome, thereby saving antenna rental space.

And, yes, I know polarization diversity goes way back in history and
has been used in HF diversity reception, but it has come back into
widespread use in cellular and PCS base stations.

Jack K8ZOA