In article ,
tom wrote:

From what I've heard there are repeatable problems, but I've heard no
coherent explanation of what might be occurring.

The thing that seems to be consistent is that left handed users have
more reported problems than right handed users.

A drawing of the iPhone 4 I saw recently (I think it was in a recent
SJ Mercury News) indicates that there is a deliberate gap in the metal
rim of the iPhone 4 - the rim that serves as the antenna. This gap is
located near the lower left corner of the phone.

If I understand correctly, the iPhone 4 has a tendency to drop calls
if it's held in a way which allows the user's hand to bridge across
this gap... presumably "short-circuiting" the antenna in some way.
A left-handed grip on the phone would put the user's palm right across
the gap - this may be the worst-case situation.

Applying an insulation of some sort to the area of this gap (an iPhone
case, or duct tape), or holding it in a way which doesn't cause the
hand to bridge the gap, reduces or eliminates the problem.

It sounds as if this iPhone has some sort of dipole or loop antenna
design, which requires that a high RF impedance be maintained at this
point. The low RF impedance of human skin is apparently enough to
de-tune or load the antenna in some way which disrupts its function.

Has anyone run across a web site showing a "tear-down" of the iPhone
4, which might clarify its antenna design?

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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