Gizmodo has a story that seems to confirm an issue with the iPhone4 antenna design.  If you hold the edge frame of the iPhone 4 with your bare hands, reception is dramatically slashed.  The image below shows this effect in full effect.

Image credit: Chris Sheehan and Gizmodo – Captions added by George Ou

When I first heard about this external antenna on the iPhone 4 on Apple’s promotional video, I thought it was the coolest thing.  I thought: finally we have a phone where the chassis doesn’t obstruct the antenna.  But if this was such a good idea, other phone makers would have done it long ago and now we see why.  It would also seem that Professor Gert Frølund Pedersen had already predicted this issue.

Apple already has a fix for this issue by selling an Apple “Bumper” case for the iPhone 4.  By putting some sort of insulating material like rubber around the sides of the iPhone 4 which act as the antenna, the adverse effects on the antenna can be mitigated.  The rubber case would likely be necessary to protect the front glass as well since it goes edge to edge and is completely exposed when dropped.  That glass might be a lot more scratch proof and bend proof, but it’s not shatter proof.

It would seem to me that if Apple should have put a thin insulating material over that metal side band to begin with instead of having a naked antenna that can’t avoid being touched, but then they wouldn’t be able to sell you a cool pink bumper.

Update – Some suspect that this is a software issue that is mainly a cosmetic problem with the signal meter, but the speedtest results above discounts that theory.  The fact that you can still make phone calls just means the phone is able to get the minimum connectivity.  Arstechnica has a much better explanation that it depends on where you hold the phone.  There are actually two antennas on the iPhone 4 and touching either one of them isn’t a problem.  But if you happen to touch both antennas with sweaty hands (more conductivity), you can bridge the two antennas and render them ineffective.

Update 2 – After seeing this report, we decided to try to repeat this test with my iPhone 4.  The test results are very interesting and fairly conclusive as you can see in the graphic below.  Speeds were cut from 1200 Kbps down to 3 Kbps and the issue was very reproducible.  George and I talk about the test results in more detail in our podcast this week, which will be posted on Friday you can find here.  – Nick

Update 3 – CNET is reporting that Apple has acknowledged the issue with the antenna. – Nick

Update 4 – Not surprisingly, Steve Jobs thinks you’re holding his phone all wrong.  Other Apple fanatics still think the problem hasn’t been proven yet they want you to put scotch tape on your beautiful new iPhone.  I’m not sure how good of an insulator that is; perhaps they should try some electrical tape.