"At the end of the day, Apple should add an insulative coating to the stainless steel band, or subsidize bumper cases. It's that simple."
The iPhone 4 loses 24.6dB of signal strength when cupped at the bottom vs 17.7dB for the Nexus one. If Apple should be required to add an insulative coating to the stainless steel, then shouldn't Google also be required to make their phone thicker (or make other adjustments) until it reaches the 14.3dB reduction of the 3GS?
If Apple is required to subsidize a bumper case, to bring the signal reduction down to 7.2dB, then shouldn't Google also be required to subsidize a case (even with a case, Google's signal reduction would still be 7.7dB).
Also, the iPhone 4 can hold a call quite well at the absolute minimum signal level of -113dBm. If the Nexus One can't do this, then should we demand that Google recall the Nexus one until it can do so?
This whole issue and the hundreds of news stories around it are ridiculous. This is not a black-and-white issue of the antenna working or not. The phone has a weaker signal for some people, and a stronger signal for others, depending on how you hold it and where you are. Take that into consideration when choosing a phone. If it's not working out for you, then just return the phone and buy one you like.
Imagine someone talking to you in a load bar. That person can, by shouting at you, make themself understood - but just barely. Although the signal is high, the noise (bar music, other conversations etc) is also high, and the quality of the communication is much reduced. That same person talking in a library could use a tone just barely above a whisper, and still be more clearly understood because the noise floor is so much lower in a library.
Many people don't realise that noise is actually the limiting factor in communications - if a signal has been attenuated, we can always just amplify it back up, but amplification amplifies the noise as well as the signal. Eventually, once the signal and the noise reach roughly equal amplitudes, amplification just gives you the noisy bar situation, you can't ever get back to the quiet library...
Bringing this back to the iPhone's antenna, we same to be in the library case, rather than the bar case. The signal that is being received when the antenna is being held is much quieter than what we see in other phones, but when we look at the only metric that really counts - bandwidth - we see that the iPhone is achieving consistently high transfer speeds, even when the antenna spacing has been bridged by someone's hand.
If I had to guess, based on the anandtech data, what we are seeing is an antenna that performs extremely well at reducing noise from the environment. Alternatively, the calibration of the sensor giving the signal strength readings in the 4G might not be terribly good. Either way, the independent tests done so far have all indicated that the iPhone 4G is outperforming every other phone out there at the moment, when looking at signal throughput.
Apple has claimed not touching the black gap or using a case helps. Random people online seem to think that sticky tape or nail polish can fix the problem. Anand seems to think some thin layer of diamond would do the job too.
Are you saying it wouldn't work? And if not could you explain why not, and what would be needed?
Your finger and the metal of the antenna are essentially two conductors separated by a thin insulator, which forms a capacitor. A capacitor blocks DC current, but its impedance (resistance) goes down as the frequency of the signal increases. What tesseract is suggesting is that the frequencies in the antenna are so high that our capacitor's resistance is practically nil; the thin insulator essentially does nothing to fix the problem.
A possible way to fix this is by lowering the capacitance of our capacitor. The simplest way to do this is to simply increase the distance between the two conductors, i.e. move the finger farther from the antenna. If you look at Apple's bumper case, you'll notice that it is far thicker than any of the proposed insulating layers.
How exactly would that affect the signal is up for discussion. It depends on how conductive is your body, what's the thickness of the coating, what area would be needed to create a visible effect, etc. etc.