We tried to replicate the problem with our own iPhone 4 models, fresh from the Apple Store this morning. At first we didn’t notice any issues with signal strength. After some effort (and help from a video so that we could perfect our technique) we were able to reproduce the problem—if your palms aren’t sweaty, we discovered it actually helps to lick them.
It’s unfortunate that Apple appears to have overlooked such an important detail—after all, attention to detail is something that Apple generally prides itself on. Given the methods that Apple used to attempt to keep iPhone 4 prototypes under wraps, though, it’s possible that wireless engineers may not have caught this issue during testing. Since those carrying prototypes had them disguised in a plastic case made to resemble an iPhone 3GS, the antenna bridging problem could have been mitigated by plastic covering the bezel.
It’s also possible that those doing the testing never held the phone in the specific way necessary to trigger the problem. Those of us on staff found that our natural grips didn’t automatically cause this issue, but cupping the iPhone 4 tightly in the palm would.
If you are left-handed or predominantly use the phone in your left hand, you may want to be aware of the problem. The known workarounds for now include holding the phone without cupping it, holding it higher up on the bezel, holding it in your right hand, or using a protective case. We certainly hope that Apple didn’t design its iPhone 4 Bumpers just to mitigate this problem.