Jim Lux Inscribed thus:

Baron wrote:
Richard Clark Inscribed thus:

On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote:

On 7/12/2010 9:46 PM, Richard Clark wrote:
The only thing that remains a mystery, for me if for no one else
here,
is the literal specification of the antenna. Google (gasp) fails
me.

73's
Richard Clark, KB7QHC
And that does seem to be the crux of the matter. What is the
antenna? And what does it interact with that's not, be it part of
the phone or part of the user?
Hi Tom,

The antenna is reported as being the metal trim that surrounds the
perimeter of the phone. As that is much too large for the
frequencies involved to be taken literally, there is more to the
story that
remains clouded. Maybe I'm wrong....

I think you're right. "Design Flaw" Someone messed up testing big
time.

If the loop (or dipole) is suitably matched, it doesn't give much
polarization diversity. Perhaps no phone does anyway.

Aren't cell stations vertically polarised. The one near me is, and
one of the IF's is smack on 144.005 Mhz.

Insofar as being "part of the user," we well know the EM of HTs and
the hand/body contribution. If such were the case, then this would
be an agnostic problem that users of all mobile phones would
complain of
(which mildly refutes what the gadget blogs dismissed). On the
other hand, the über-hip, whose complaints are more vocal for their
"pain," would be outraged at the notion of their simply enjoying the
identical
experience of techno-trash. Amazing what a 10 fold cost
differential brings to your perception of quality of service.

73's
Richard Clark, KB7QHC

From a casual look at the phone the metal band seems to be a
continuous loop. Its unlikely that there is a physical coupling
between it and the RX/TX, so any tuner or coupling is going to be
affected by the hand
grasping it. Since suggestions have been made to hold the phone in a
different place, I would guess that the coupling method is suseptible
to adsorbtion effects and that the hot parts are near the base of the
phone.

FWIW Every mobile phone I've played with has the antenna and coupling
circuitry near the top behind the display.


Not any more.. recent phones (last several years) put the antenna at
the bottom to reduce the SAR number, since the top of the phone is
next to
your head, and the bottom isn't. There's a really good explanation
from a guy who does, oddly, wireless device antenna design
consulting.. http://www.antennasys.com/
specifically

http://www.antennasys.com/antennasys...-antennas.html


http://www.anandtech.com/show/3794/t...one-4-review/2 has some
information

Jim. Thanks for the above links. The Youtube vid was most interesting.
I certainly wasn't aware of the gaps in the metal banding nor of the SAR
requirements.

73s
--
Best Regards:
Baron.