Within the dark depths of AT&T’s network blackhole known as ‘South Austin’ – my iPhone 4 is working perfectly. Okay, it dropped one call – the same place it always does. Other than that, voice quality and reliability is much improved. Granted this is not a scientific study – but I suspect that my experience isn’t as isolated as the media and blogosphere would have you believe.
Besides being a elegant hand-held workhorse – the iPhone is also a radio. And all radios fall prey to certain constraints of electronics and wave propagation.
In the iPhone 4, the antenna is exposed in the bottom portion of the stainless steel band – no longer internal as was the case in previous models. The left segment serves Wi-Fi and Bluetooth frequencies, while the right segment is for the data and voice communication. Each segment is tuned to provide optimal coupling to the respective radios. Coupling is a fancy way of saying the most efficient way of transferring energy to and from the transmitter and receiver.
The AT&T cell towers have larger equivalent antennas coupled to much bigger radios. The mobile phone and each cell tower a phone touches, do a continual dance, adjusting transmitter power and receiver sensitivity to compensate for many things… including terrain, weather, and hands covering or touching a part of the mobile antenna.
When your hand touches the antenna, the ‘coupling’ efficiency of the antenna changes, which could in some cases affect reception or call quality. There are also carrier-side adjustments that can mitigate those effects.
I’d suspect that an update will be released soon so that the iPhone 4 can tolerate greater amounts of user attenuation and capacitance. Remember, when your hand touches that stainless steel band – you become part of the antenna. And FCC requirements require Apple and other mobile handset manufacturers to limit SAR, specific absorbed radiation – which why perhaps, Apple chose to be conservative in setting tolerances.
Apple holds several core patents for antenna design, including adaptive coupling. So you can be sure that help is on the way.
Please post a comment and let us know how your iPhone 4 is doing!