Apple iPhone 4 Reception Problems a Lesson in Antenna Design
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 does.
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 signals.