Apple's iPhone 4: Thoroughly Reviewed - AnandTech :: Your Source for Hardware Analysis and News
Page two goes into a thorough analysis of the antenna. It finally explains how it works and why some can get the bars to disappear and some cannot by holding it.
If you do not want to read it all. A summary is that if you are close enough to the cell tower, your hands are not enough to block the signal no matter how you hold it. But, you can still have 5 bars and be far enough from the cell tower that holding it in the death grip will knock it down to 0 bars. The iPhone essentially shows 5 bars until it has a very low signal then it drops off rapidly.
It is interesting that the bumper case fixes most of it, but there is till more signal attenuation than the 3Gs. But, it appears that the antenna design is much better and the electronics more sensitive that it does appear to hold a call with a lot less signal.
Page two goes into a thorough analysis of the antenna. It finally explains how it works and why some can get the bars to disappear and some cannot by holding it.
If you do not want to read it all. A summary is that if you are close enough to the cell tower, your hands are not enough to block the signal no matter how you hold it. But, you can still have 5 bars and be far enough from the cell tower that holding it in the death grip will knock it down to 0 bars. The iPhone essentially shows 5 bars until it has a very low signal then it drops off rapidly.
It is interesting that the bumper case fixes most of it, but there is till more signal attenuation than the 3Gs. But, it appears that the antenna design is much better and the electronics more sensitive that it does appear to hold a call with a lot less signal.
