Friday, June 25, 2010

The origin of the iPhone 4's signal problems?

Fans of government intervention and regulation believe that it is possible to create complex guidelines for businesses which give us only benefits and no detriments. But the reality is that every government regulation has an unintended consequence and one antenna designer is suggesting an FCC regulation is behind the reported iPhone 4 antenna issues. It may explain several other mysterious decisions behind Apple's designs in previous generations.

Just about every cell phone in current production has the antenna located at the bottom. This insures that the radiating portion of the antenna is furthest from the head. Apple was not the first to locate the antenna on the bottom, and certainly won't be the last. The problem is that humans have their hands below their ears, so the most natural position for the hand is covering the antenna. This can't be a good design decision, can it? How can we be stuck with this conundrum? It's the FCC's fault.

You see, when the FCC tests are run, the head is required to be in the vicinity of the phone. But, the hand is not!! And the FCC's tests are not the only tests that must be passed by a candidate product. AT&T has their own requirements for devices put on their network, and antenna efficiency is one of them. I know because I have designed quad-band GSM antennas for the AT&T network. The AT&T test similarly does not require the hand to be on the phone.

So, naturally, the design evolved to meet requirements - and efficient transmission and reception while being held by a human hand are simply not design requirements!
I can confirm that I have seen this issue with my iPhone, and it now appears Apple has acknowledged the issue. But it is interesting to see how it came about, and the pressures that may have justified it. In the meantime, many users are looking into cases to alleviate the issue.

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