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iPhone 4 antenna woes contextualized by dude in the know
It's the ultimate of ironies that Apple's externalized antenna array in the iPhone 4 -- hoped (and hyped up) to finally give us a phone every bit as good the rest of the device -- has become the cause of most rancor in the immediate aftermath of the handset's release. This morning you'll be rubbing both sleep and disbelief out of your eyes as you read that Apple's response to some people's reception problems with the 4 is to hold it differently. But, before we start ostracizing Apple as the singular offender here, let's hear from a man in the know. Spencer Webb runs AntennaSys, a company that designs tailormade RF solutions, and has himself worked on making quad-band transceivers for AT&T. As he tells it, almost all phone makers have now transitioned to locating their antennae at the bottom of the phones. This has been in order to move radio wave emissions away from the head (a shortcoming that a top-mounted aerial would incur), which the FCC has been quite demanding about with its SAR standards -- The iPhone 4, however, moved the antenna action from the back of the phone to the sides. This probably improves the isotropy of the radiation pattern, but only when the phone is suspended magically in air. Another great point made here is that testing done both by the Federales and mobile carriers might include the head, but never accounts for the presence of the person's hand. Thus, although a phone's antenna could test very well, it might suffer from such issues as those experienced with the iPhone 4. Mind you, this still seems like an assembly (rather than design) problem to us, since most of our editors haven't had any reception worries and we in fact saw improved performance on that front while conducting our review testing. Spencer himself has decided to buy the phone knowing full well about this potential limitation, and concludes on the note that "sometimes an antenna that's not great, but good enough, is good enough."
The science behind the iPhone 4's antennas
The iPhone 4's outer ring of antennas has been earning some grief lately as some owners have found that reception can change even based on where your hand is placed. Even Steve has weighed in on this issue via his itchy email finger. Spencer Webb of AntennaSys (an "antenna design" firm) knows the science, though, and he's shared a little outsider wisdom on how the iPhone's metal actually works. Webb starts by talking about the design of cell phone antennas in general. He says that most antenna placement these days is based on FCC rules about how much energy a device can send into a user's head; that's the reason most antennas are at the bottom of phones nowadays. Unfortunately, our hands are usually on the bottom of the phone, and the FCC doesn't test energy absorption through the hands, only through the head. What's the ideal way of holding your phone? You should hold it by the top, as if it were hanging in midair. Where does the iPhone 4 fit in all of this? Webb says the antennas in the new iPhone are on the sides of the phone, which means that, yes, there's potential for your hands to block energy. But there's always the potential for that, and Webb says that if you put your phone somewhere away from you and use a Bluetooth headset, none of it really matters anyway. What's the final verdict? Webb himself preordered an iPhone 4 to replace his original iPhone. Sure, the antennas might not be perfect, but given the quality of the phone (not to mention the experience), "good enough, is good enough."
