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Experts Explain iPhone 4 Antenna Problem 427

CWmike writes "Reports of call and data signal strength problems in the new iPhone 4 have a basis in fact, a hardware expert said Thursday. Later in the day, Apple acknowledged that holding the iPhone 4 may result in a diminished signal that could make it difficult to make and maintain calls or retain a data connection. 'Gripping any phone will result in some attenuation of its antenna performance with certain places being worse than others depending on the placement of the antennas. This is a fact of life for every wireless phone,' Apple said in a statement issued to several media outlets, including PC Magazine, which had run tests earlier Thursday. 'If you ever experience this on your iPhone 4, avoid gripping it in the lower left corner in a way that covers both sides of the black strip in the metal band, or simply use one of many available cases.' Scores of new iPhone owners confirmed the reception problem in a string of more than 360 messages posted to a thread on Apple's iPhone 4 support forum." A blog post from an antenna design company explains that the reception problems are probably the direct result of phone design adapting to FCC requirements.
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Experts Explain iPhone 4 Antenna Problem

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  • Cases (Score:5, Interesting)

    by Peach Rings ( 1782482 ) on Friday June 25, 2010 @06:11PM (#32697304) Homepage

    How will wrapping the phone in a case and then holding it the same way as before fix the problem?

  • by 91degrees ( 207121 ) on Friday June 25, 2010 @06:24PM (#32697450) Journal
    The iPhone 4 has two symmetrical slots in the stainless frame. If you short these slots, or cover them with your hand, the antenna performance will suffer (see this video I found on YouTube). There is no way around this, it's a design compromise that is forced by the requirements of the FCC, AT&T, Apple's marketing department and Apple's industrial designers, to name a few.

    Possible solutions include:
    • having another small slot so the two antennae aren't right next to each other and you'd have to short both slots.
    • Cover with a non-conductive coating
    • Put the antennae actually inside the phone.

    I guess there are some extremely complex technical or aesthetic or regulatory reasons why each of these isn't going to work but I'd like to know what they are.

  • Re:Cue the fanbois (Score:5, Interesting)

    by PolygamousRanchKid ( 1290638 ) on Friday June 25, 2010 @06:29PM (#32697498)

    Next thing you know, holding a cell phone with the thumb and forefinger by the top right corner will become the fashionable way for any of the cognoscenti to hold their phones.

    So how come this problem was not identified during the system test of the device? Were all the testers instructed to hold it that way? Or maybe they identified it, but did not have the courage to report it?

  • by Namarrgon ( 105036 ) on Friday June 25, 2010 @06:41PM (#32697632) Homepage
    This guy is an expert in antenna design from Aalborg University, and predicted this [] two weeks ago.
  • It may have been (Score:4, Interesting)

    by Sycraft-fu ( 314770 ) on Friday June 25, 2010 @06:49PM (#32697724)

    And it may have been dismissed. Apple is very much about form over all else. The most important thing to them is how something looks. Features and function get subverted to that end. They've had other devices with problems due to their designs. Time Capsules are an example. They have a bad habit of failing after a year and a half or so, way more than you'd expect. Reason is the internal power adapter. It puts too much heat in the small case and causes failures. The smart thing would have been to have it external, but that would ruin the look.

    So Apple may have known this was a problem and said "Fuck it, people can just hold it as not to touch the antennas. We don't want to hurt the looks."

  • by Luckyo ( 1726890 ) on Friday June 25, 2010 @06:50PM (#32697734)

    Actually this was touted on iphone4 introduction speech as a "major new feature" by Jobs. It was kind of obvious for anyone who actually ever worked with antennas that it was trouble. But apparently it sounded fashionable to countless ears of apple clients.

    It's a feature among others, aimed to increase hype value of the device. It's pretty obvious why no one else did it, and hence probably seemed like a good marketing idea to apple. All it had to do was what it always did, present it as an awesome revolutionary new feature.

  • by MichaelSmith ( 789609 ) on Friday June 25, 2010 @06:54PM (#32697774) Homepage Journal

    Maybe their validation staff have small fingers. More likely testing was done with the device flat on a bench with people checking boxes to verify correct display on the screen.

    I see this all the time in my work. Our system just isn't used in the same way it is tested.

  • Re:Cue the fanbois (Score:5, Interesting)

    by Anonymous Coward on Friday June 25, 2010 @06:58PM (#32697820)

    So how come this problem was not identified during the system test of the device?

    Because - you'll really love this - they put it in an iphone 3 case when they were supposed to be testing it so as to keep the super shiny design secret. Really. The product they were testing wasn't the product they were planning to launch. Bunch. Of. Cowboys.

  • Re:Cases (Score:5, Interesting)

    by icebike ( 68054 ) on Friday June 25, 2010 @07:02PM (#32697862)


    Its not that the antenna is at the bottom, its because it is external, and metal, and skin is conductive.

    This is a fundamental design flaw that I can't believe they let slip. Now they will probably have to offer discounts on "bumpers" to bring the phone back up to published specifications.

    Using external antennas that can be shorted by normal hand moisture! I'm not aware of any other phone that does this. Why was it necessary with a glass backed case? The antenna could have been at the bottom like prior iphones. []

    There is SO Much about this iPhone release (hardware and software) that has been problematic that I am starting to believe Apple's claims that the leak of the "lost" phone was indeed damaging to Apple. I think it forced their hand, and cornered them into releasing a phone that was not yet ready with software that still had a lot of problems.
    The fanboys will be here momentarily to mod this down. Sigh.

  • Re:Cases (Score:4, Interesting)

    by dangitman ( 862676 ) on Friday June 25, 2010 @07:06PM (#32697928)

    And the real question is why they made the bottom strip out of metal since it's not an antenna.

    Perhaps because it *is* an antenna? It doesn't have just one antenna, but multiple antennae circling the phone, for Wi-Fi, GSM and Bluetooth.

  • Geeks and Apple (Score:3, Interesting)

    by Gary W. Longsine ( 124661 ) on Friday June 25, 2010 @07:28PM (#32698172) Homepage Journal
    Oh, I guess that's funny in a Slashdot sorta way, but I'm not the first person to notice that conventions of programmers, like Java One, or BSDCon or various hacker and security geek conferences are seas of glowing Apple logos, the past few years. I know that among the programmers I know, it's actually the best programmers (the ones that I would recruit for any project on any platform with any language) who are nearly all on Mac OS X. Maintenance programmers tend to stick with the platform they work on during the day (usually Windows), but even some of those have switched to the Mac at home.
  • by tgibbs ( 83782 ) on Friday June 25, 2010 @08:12PM (#32698528)

    Agreed. The Magic Mouse is the best mouse I've ever used.

    But whether you like an Apple mouse depends heavily on your mousing style. Apple mice are designed for people who control their mouse with a light touch of their fingertips. People who like to rest their palm on the mouse tend to prefer a more "mounded" design, and find the flat, low-profile Apple mice uncomfortable.

  • Re:Cases (Score:5, Interesting)

    by Gary W. Longsine ( 124661 ) on Friday June 25, 2010 @08:37PM (#32698692) Homepage Journal
    I was initially skeptical that this might be software related, but recent rumors have a plausible software theory. The new iOS 4 has a new algorithm for picking the tower and channel that the phone uses, when it can see more than one. It appears that this mechanism may have a defect which is triggered by attenuating the signal (such as by bridging the two antennae with salty skin). This appears to cause the phone to decide to attempt switching channels. The speculation is that the timing is off, and the phone sometimes reports "no signal" rather than deciding to switch or stay put.

    Death Grip hysteria may end Monday with iOS 4.01 []

    The issue described is plausible, and fits some of the observations.
    • Some folk can reproduce this problem, basically at will (one of the magazine review sites).
    • Other folk are unable to reproduce this problem, at all (another reviewer at the NYT).
    • At least some folk who can reproduce this issue are doing so in areas where reception was previously known to be marginal (including one of my developers at his house).
    • The problem may have been harder to diagnose during Apple's testing, due to pre-release testing taking place inside insulated cases, thus the problem would be triggered less often, and not in associate with anything special that the user would notice (holding the phone in a certain way). The frequency of dropped calls might have been within the "normal" range for the AT&T network, given the small sample size of a few hundred test users. (Apple's off site testing includes hundreds of people, but that's actually a pretty small sample size, compared to the 600,000 people using the phone today.)

    It will be interesting to see if a software patch emerges within a few days or even weeks, and cures this issue. If it does, I'll think back to several cell phones I had previously, which had problems that I could and did reproduce, and reported clearly to the vendors (both network and cell maker) and for which no patches were forthcoming, ever, during the life of the phone. Regular software updates for iPhone are a damn sight better than the old way, where the answer to any problem was "buy the new version of the phone you just bought a month ago".

  • by jjb3rd ( 1138577 ) on Friday June 25, 2010 @08:42PM (#32698732)
    I think this is a load of crap myself. I bought the iPhone 4 at launch with the bumper. That said, I immediately looked for yellow spots on the screen and tested this reception problem sans bumper. There are no yellow spots, no sparkles, and no reception problems, even when intentionally holding the way described. I am not experiencing any problems. It is a beautiful device, it is VERY VERY fast...the kind of noticeable speed difference there was going from a 386 to a pentium. Also, the screen is so nice. I literally cannot see pixels on it no matter how close I get to it. I can't wait until this is the norm for TV's and monitors...Frankly, the only thing that ticks me off is that my brand new Macbook Pro doesn't have the same screen...mmm, that would be nice. On a side note, Slashdot has really gotten a tad snooty with this walled garden bullshit. Some people like to sunbathe naked in their walled gardens. Some of us think it's a bit tacky to sunbathe naked in public gardens. Really really good shit happens inside of walled gardens, and you serfs on the outside will always bitch. Noone here likes to point out Apple's open source contributions anymore (Darwin and Webkit), nor do they like to point out that Apple pushes open standards (HTML5, WebDAV, CalDAV, etc). PLUS, Mac is UNIX...real UNIX, and a really good implementation of it at that, yet all I hear on this site is some snooty attitude like Android is better because it's more open...meh, I've got two words for all you haters out there: FaceTime PhoneSex.
  • Re:Cue the fanbois (Score:5, Interesting)

    by Dahamma ( 304068 ) on Friday June 25, 2010 @08:51PM (#32698792)

    Luckily the human body is a pretty poor conductor, as long as you are not standing in the shower (which I believe would be a bad place to talk on the phone anyway).

    I can say from first hand testing that the initial quality of the signal has a lot to do with the attenuation caused by this issue - if you already have a good signal it doesn't seem to cause any problems.

    Anyway, as you said, the fact that this was missed is pretty amazingly bad testing, especially considering how Jobs actually described in the keynote that the reason the metal on the outer rim had a visible break was because it acted as an antenna. Wouldn't you think the *first* question one would ask as a tester (or an engineer!) is "hmm, these are not connected for a reason - I wonder what happens when I connect them with various common household objects, like, say - my HAND?"

  • Re:Cases (Score:4, Interesting)

    by icebike ( 68054 ) on Friday June 25, 2010 @08:54PM (#32698814)

    For this theory to be believable, the phone would have to be failing one other key feature of cell tower hopping, namely keeping track of the relative signal strength of multiple towers at all times.

    Attenuation would affect all towers in the same band roughly evenly. It might not affect different bands the same, and the phone might be dropping to EDGE of something like that.

    But I still don't see how this gets out of the lab and thru field testing.

  • by alvinrod ( 889928 ) on Friday June 25, 2010 @09:16PM (#32698970)
    Funny thing is that it's not the first time. Some reproduced the issue with an old Nokia candy-bar style phone [] and put a video of it up on youtube. I don't have the link handy, but some site pointed out a Nexus One discussion thread from several months ago that discussed a the same issue. Just for fun I just took my own phone out of my pocket and observed the different in signal strength when it's just sitting on my desk and when I hold it. It loses a bar, but I've never noticed before because I've never thought to look at it, most likely due to the fact that I generally good good reception on Verizon and wouldn't think to look at it that closely. The only reason so many people are experiencing it for the first time are because the people who buy Apple products have a greater tendency to obsess over shit like this and post about it on the internet. Then the internet denizens, who collectively get hardons over all things Apple, endless talk about it. If it weren't for Apple, this would almost be a non-event that ends of being drowned out by all the other noise.
  • Re:Cue the fanbois (Score:2, Interesting)

    by Anonymous Coward on Friday June 25, 2010 @09:17PM (#32698976)

    Don't forget Apple's motto: form before function.

  • by Anonymous Coward on Friday June 25, 2010 @09:33PM (#32699080)

    The problem was duplicated in a 3GS after the upgrade to iOS4, meaning the problem appears to be software related, not hardware related. A rumored 4.0.1 updates is being forcast for Monday that will supposedly address the issue. That said, I haven't noticed any dropped calls, or any 'no service', but I have seen signal drop by 1-2 bars. Putting any case on it also resolves it.

  • Re:Cases (Score:5, Interesting)

    by cybereal ( 621599 ) on Friday June 25, 2010 @09:43PM (#32699144) Homepage

    The effect of attentuation drops off exponentially as you remove the attenuating obstruction from the antenna. However, there is reason to believe that there is a different problem besides attenuation affecting a very small number of handsets. Personally I suspect some kind of ground fault in the casing leading to a magnetic field interfering with the radio itself. This wouldn't demonstrate itself as the loss of a couple bars, it would be complete or nearly complete loss of signal.

    That said, I have an iPhone 4 and cannot reproduce any of the reported problems at all no matter what I do. I have to put my phone in what almost amounts to a faraday cage (a steel lock box) just to see any signal degradation. But a friend of mine has seen the problem occur with nothing but the tip of his finger placed over the antenna on the left side, specifically when touching the metal. The metal plates are not the antenna, the black lines are, so what this tells me is that there is some issue with grounding of the body in that phone. But until I can have him try his "magic finger" on my own iPhone, I wouldn't jump to any real conclusions. None of the reports so far have been remotely scientific. There are numerous variables and without any cross checking it's all guesses for now. Attenuation will definitely occur but it's usually not so dramatic as to go from five bars to "Searching..." like this friend of mine is seeing.

  • by Jarik C-Bol ( 894741 ) on Friday June 25, 2010 @10:55PM (#32699516)
    I enjoy many apple products. However, they do not shit rainbows and butterflies. I am aware that they, like every other company on the face of the planet, from time to time, produce an inferior product. Your welcome to your personal shit-fest about apple, but really, if your that butt hurt about the existence of the company, then go cry in a corner you emo prick.

    I want you to consider how shitty the home computing world would be if Microsoft never had ANY market competition. Imagine for a second how shit-tacular whatever OS we would be using would be if there were no competition between Apple and Microsoft. They are polar opposites in many ways, and wether they admit it or not, they strive to out do one another in the OS department. Without competition, the OS world would be a disgusting wasteland.

    Apple is damn sure not a golden god on a unicorn with butterfly wings like some idiots make them out to be, but your fanatical 'anti apple' stance is just as moronic. /rant goodbye karma....
  • Re:It may have been (Score:5, Interesting)

    by hobo sapiens ( 893427 ) <TEA minus caffeine> on Saturday June 26, 2010 @12:25AM (#32699944) Journal

    And they would have been correct - they will sell more from looks and the Apple fans will not only hold it different or purchase the rubber pads but will sing the praises of having to do so.

    I use a Macbook Pro as my development machine. I love that computer. It runs like a champ, is fast, battery life is great, and the trackpad is just about my favorite piece of computer hardware ever. It's great...except for the PERFECT right angle along the perimeter of the thing. A perfect right angle + solid aluminum construction = sore wrists for me.

    I googled it to find out if I am alone in disliking the sharp edge along the perimeter of the thing. There were not just a few people touting this as A Good Thing, because after all everyone uses a computer in the same way and you are NOT supposed to rest your wrists on the mighty macbook after all, so Apple was just helping me to learn how to properly use a computer. An obvious design flaw justified away by so many people. I like my iPhone, I like my macbook, so I guess that makes me an Apple fan. But to justify design flaws, as though Apple were incapable of such a thing is inexcusable.

  • Re:Cases (Score:1, Interesting)

    by Anonymous Coward on Saturday June 26, 2010 @12:29AM (#32699964)

    You can literally suck on an antenna broadcasting at 2W and not feel a thing (I've done it)

    ...... Why? Wait, I don't want to know.

  • Re:No, even then (Score:3, Interesting)

    by thegarbz ( 1787294 ) on Saturday June 26, 2010 @12:36AM (#32699988)
    Not required. Proximity would have enough of an effect on the system. Remember we have a device here which passes power despite having two completely open ends. Putting a resistor across the terminals (your hand) would have an effect even if it wasn't directly touching the device.

    To that effect, a case that that provides a 1-5mm buffer between the antenna and your hand will have a much larger effect than a semi-conductive coating (because at 2.4GHz frankly a lot of things are semiconductors) 1micron thick applied by wiping on the inner thigh of a Swedish virgin*. *I think only Steve's iPhone is constructed this way. The rest of the world gets some Chinese hag with syphilis.
  • Re:It may have been (Score:3, Interesting)

    by PapayaSF ( 721268 ) on Saturday June 26, 2010 @12:42AM (#32700014) Journal

    I had the same issue with my MacBook, but the plastic case meant it was easy to get some fine sandpaper and take the edges down a bit.

    Yes, Jobs does stumble sometimes with his design sense. The notorious round mouse of 1998-2000 [] is another prime example.

  • Re:Cue the fanbois (Score:4, Interesting)

    by FreonTrip ( 694097 ) <freontrip@ g m a> on Saturday June 26, 2010 @07:12AM (#32701422)
    Why would you quibble about such a beautiful thing?
  • by catmistake ( 814204 ) on Saturday June 26, 2010 @05:04PM (#32704654) Journal

    By now you’ve all heard reports that the iPhone 4 has a “terrible design flaw” that makes it useless for calls once you pick it up. Well, ok, I’m exaggerating a bit but you’d be forgiven for thinking that with the way this story has spread like wild fire. Now, I don’t doubt that some people are having an issue with this, but I’m amazed at the way this story was reported and the way it was picked up by the mainstream news media. First of all, Gizmodo were pushing this big time on Thursday, along with any other story they could find to paint the iPhone in a bad light (including, surprise surprise, you drop it and it breaks). Big surprise. From there other blogs started picking up on it and then it reached the mainstream media. What amazes me about this is that, first of all, most of the people reviewing the phone never noticed an issue with it and that most reviewers had noticed improved reception.

    Secondly, as has already been pointed out, the same thing happens to existing phones. When Apple said this in their email they were set upon by bloggers for being dismissive of the “fatal design flaw” but they’re telling the truth. I tried it with my iPhone 3G and it does the exact same thing. Hold it in the bottom left corner and the signal drops. I’ve had my phone for over 2 years and I never noticed this issue until someone pointed it out and I tried to replicate it. But what I find really telling about the reporting on this is that virtually none of the mainstream media reports into this did any research or looked even remotely into the issue. They just reported on the Gizmodo story coupled with a few anecdotes from viewers or readers who were having reception issues. I’m not trying to down play the problems of those who are having problems, what I’m annoyed about is the complete and utter lack of perspective. For a start, a little bit of research would have found out that the Nexus one had the exact same issue when it was launched. But where was the outrage there? Where was the massive controversy about the Nexus being “flawed”? Why wasn’t this pushed as the main story by Gizmodo for several days? It certainly never reached the mainstream media, and yet according to the people experiencing the issue, it’s pretty much the same.

    The problem is now that regardless of the extent of the reception issue, it will forever be seen as the “design flaw” of the iPhone. Anyone who tries to point out that other phones do in fact experience this are immediately branded as fanboys. It’s amazing how people are so eager to buy any controversy that involves Apple that they loose all sense of reason or balance. It’s gotten so bad lately that I’ve almost given up blogging about Apple and the mac, two subjects close to my heart. It seems that people are only interested in expressing phoney outrage at some inconsequential thing Apple does and creating giant controversies out of insignificant issues (I’m not talking about the iPhone 4 reception issue here before people start giving out about that I’m saying it’s an insignificant issue – although for many people apparently it is). It’s amazing to me how there has developed this complete disconnect between the impression you get about Apple from reading technology sites and publications, and the reality on the ground. The tech press (particularly tech blogs*) has lately been overwhelmingly negative about the Cupertino company, and yet contrast that with hundreds of thousands of people queuing for an iPhone 4. We’re given the impression that the iPhone is a terrible platform for developers and that its atrocious policies mean developers are abandoning it in droves for Android, and yet contrast that with WWDC selling out in 8 days.

    I think the root of the problem, or at least part of it is the way a story spreads. It often starts on a blog when someone publishes their opinion on something

  • by Loomismeister ( 1589505 ) on Saturday June 26, 2010 @06:24PM (#32705212)

    Actually, this design flaw affects 100% of the phones. If you have an iPhone and hold it in your left hand, bridging the millimeter gap in the metal band that goes around the perimeter of the phone, then it will lose it's connection. 100% of the time this will happen.

  • Re:Cue the fanbois (Score:3, Interesting)

    by Lars T. ( 470328 ) <> on Sunday June 27, 2010 @05:41AM (#32707954) Journal

    Next thing you know, holding a cell phone with the thumb and forefinger by the top right corner will become the fashionable way for any of the cognoscenti to hold their phones.

    So how come this problem was not identified during the system test of the device? Were all the testers instructed to hold it that way? Or maybe they identified it, but did not have the courage to report it?

    Or maybe it doesn't happen on all iPhones. []

    One iPhone 4 demonstrated the issue everytime it was held in our left hand (...) Our second UK-purchased iPhone 4 was fine, showing none of these handling symptoms. (...) P.P.S. Since some of you are asking, our review unit showed none of these issues.

  • Re:It may have been (Score:3, Interesting)

    by Dixie_Flatline ( 5077 ) <vincent DOT jan DOT goh AT gmail DOT com> on Monday June 28, 2010 @11:13AM (#32716848) Homepage

    I feel like you're only half right.

    Apple's belief has always been that function FOLLOWS form. The user interface guidelines that they publish dictate form because it results in better function from a user perspective.

    This still holds true for the iPhone 4; getting Facetime to work is function, getting it to work without a bunch of tedious setup is form. Because they required it to work without a bunch of tedious setup, we're only now seeing it in generation 4 of the phone; before pure function is allowed out the door, the form must be acceptable.

    Apple's very good at marketing, and we all remember CmdrTaco's famous comments on the original iPod, another device that seemingly put form first. But that form dictated the function, and it brought MP3 players into the mainstream. This is why Apple's products STILL make them so much money.

    In this case, it would have been better for them to do a bit more form->function->form revision, I guess, but sometimes things work just good enough to get out the door, no matter what company you're talking about. And this is a limited problem (not everyone can reproduce it) with a few easy fixes. In the video games industry this would be classified as a 'KS' bug: 'Known Shippable'. And they did. :)

  • Re:Cue the fanbois (Score:3, Interesting)

    by xtal ( 49134 ) on Saturday July 03, 2010 @05:05PM (#32788100)

    DC resistance of your skin is not the only effect here.

    The admittance change from your finger adding capacitance and changing the inductive value of the antenna changes the antenna's tuning and ability to effectively radiate. This adds up to the antenna being much less effective.

Who goeth a-borrowing goeth a-sorrowing. -- Thomas Tusser