Not that I have an iPhone 4 (yet) but its interesting reading the various reports on the loss of signal strength (and inevitable dropped calls) that seems to be caused by holding the phone in the left hand.
It does seem obvious to me that as the skin is electrically conductive, that if you bridge the gap between the 3G antenna and the WiFi antenna that make up the edge of the iPhone 4 case, you are potentially going to affect received or transmitted signal strength. You might even be slightly altering the frequency of transmission, as the antenna construction will no doubt be tuned to the wavelengths being used. It probably makes a difference how sweaty the user is as well, as that will affect the conductivity of the skin.
Notice in the image that there is a gap at the top of the phone case as well, but who holds their phone upside down (as the mic would be in the wrong place) but you can guarantee that the effect is the same.
The problems are alleviated by holding the phone in such a way as to avoid bridging the gap with your skin, or by putting the phone into one of Apple’s bumper cases that effectively covers the steel parts. Apple obviously decided that shiny steel was more alluring than rubber as part of the original design, and using the case edge as part of the antenna system is inspired thinking.
But why didn’t Apple notice this in testing? Simply, its Apple’s own draconian measures on product secrecy that would have led to this. Any device leaving the Apple facility would have definitely had to be placed into a case to protect its identity, and the chances are that even in the facility devices are shrouded in some way to prevent employees taking photos of the device and spoiling the launch event for Steve. As a result, you can bet that very few people were touching the steel antenna with their bare hands during testing, and if your testing largely in metropolitan/urban areas a dip in strength would go unnoticed when the phone is next to the head, whereas a dropped call might be (and even then, by the time you’ve moved the phone from your ear, adjusted hand position etc, the strength might come back and you’d be hard pressed to understand why the call dropped). Most complaints of this sort of problem with earlier iPhones have tended to blame the cell provider, mostly AT&T, who may be entirely innocent.
I think these reports are a great shame for Apple, as its bound to tarnish the image of the product in terms of quality and reliability. Whilst the bumper case is a reasonable solution, and practical for most people anyway as its any protective case), I can’t help thinking that Apple will be updating the design quite quickly to include some sort of plastic laminate coating to the steel Antenna, so that the aesthetics are not diminished, but the signal quality is restored.