News Analysis: The iPhone 4 has a very good antenna design as long as you let it do its job. The antenna design demonstrates that the best antenna design from an engineering standpoint isn't necessarily the best design from a usability standpoint.
Imagine, if you will, a day when the term "wireless" had a lot to
do with Morse code. In those days if you wanted to transmit signals, you had to
get a license from your national regulatory authority, which in the United
States is the Federal Communications Commission.
One of the areas where you had to pass a rigorous test was in antenna design.
Since then, things have changed a lot.
Probably the thing that's changed the most is that people
are allowed to operate radio transmitters without a license, which means, among
other things, that you don't need to take and pass a test before you can use
your WiFi router or your cell phone. But it also means that most people don't
really understand how a radio antenna works, or for that matter, what it
iPhone 4: What's All the Hoopla About? Find Out Here
The reason I mention this is the current round of
complaints about poor reception with the iPhone 4. Apple's response is to not
hold the device so that your fingers cover that thin black band on the lower
left of the iPhone 4's outside edge. The reason this causes a reception problem
is that this thin black band (and a similar one on the other side of the
device) is actually the insulator that separates two antennas, one for the UHF
part of AT&T's voice band and the other the microwave 3G, WiFi and GPS
When you touch this thin black band, you provide an
electrical pathway between these two antennas. How much of a pathway you create
depends on your personal physiology and the conductivity of your hands. Your
hands can change these characteristics when they're wet, and especially if they're
sweaty, since perspiration contains salt, which aids in conduction.
It's part of the basic design
of the iPhone 4's
antenna that you can affect its reception in this way,
but that doesn't translate into saying that it's a bad design. Like the antenna
design in every other cell phone, the iPhone 4 design is a compromise. The
engineers who designed it had to choose between an efficient antenna that would
overcome some of the reception problems that had spurred earlier complaints and
some worse reception problems that currently plague other
In most wireless devices these days, the antenna is
printed on the main circuit board, or one that's situated next to it. It looks
like a copper zig-zag design, and it's usually under the keyboard or the
battery, although there are many places where the designers place them in the
interests of looks, convenience or sometimes efficiency.