Consumer Reports has recently just released a report which somehow “proved” that the iPhone 4 does have a signal drop issue when a person hold the phone or touch the phone at the particular (bottom left) area.
But an EMC engineer disagree with the report, saying that CR (short for Consumer Reports) didn’t used a controlled environment for the tests, thus, the results are not to be taken as valid.
While I may not be an EMC, EME, RF or an antenna engineer, I do know my way around the lab, the equipments and RF testing. Working right next to all 3 EME, EMC and RF labs does give me enough experience to comment on this.
First of all, controlled tests are always good to reproduce accurate and repeatable results to measure the performance of the device. This is important as to show that the device complies with regulations and does not interfere with other signals. For example, SAR tests performed by EME labs measures the rate at which energy is absorbed by the body when exposed to a radio frequency (RF) electromagnetic field. Too much, and it’s considered dangerous for humans. EMC tests on the other hand, will test the radiation pattern and power of the device in a controlled room where RF noise are shielded and reflections absorbed. Humans aren’t supposed to be inside and even the attached measuring instruments outside the room are shielded.
The problem with all these very expensive, accurate and exhaustive testing is, although they try to reproduce real world issues as much as possible, it’s still a controlled test up to a certain degree of acceptance. They can never be able to capture a full range of problems which can happen in real world environment. There are too many things which can happen outside the lab and there are always reasons why all these electronic devices have updated hardware revisions.
New tests are always developed to reproduce those reported issues to try to determine the cause and action needed. If the problem is hard to reproduced in the controlled environment, then it’s further escalated to R&D to capture the problem on the board level.
What Apple is doing on the other hand, is trying to blame others for their problem. Are Apple’s engineers really working on a fix is anyone’s guess but everyone should always take those Consumer reports with a pinch of salt. It’s not a controlled test. But every “Professionals” should also never ignore the public opinion even when the problem is not done through controlled environment. A problem is still a problem and an engineer’s job is to provide solutions to a problem. Not to provide excuses!
