Experts Explain iPhone 4 Antenna Problem

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.

Comments

Cue the fanbois

[plover]

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. Those of us who cradle them in the old fashioned way will be "not of the Body of Jobs", and mocked and ostracized.

Re:Cue the fanbois

[Anonymous Coward]

Sorry, but there is only one correct way to hold a phone

Re:Cue the fanbois

[Anonymous Coward]

Are you sure?

Re:Cue the fanbois

[PolygamousRanchKid]

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?

Re:Cue the fanbois

[LBArrettAnderson]

In a sane world there's no way that my theory can be right, but here it is:
 
The lab tests were done at Apple HQ, where AT&T has a tower in order to keep Steve Jobs happy -- plenty of signal even with the defect. The field tests were done with the rubber disguises on, so it didn't affect them.

Re:Cue the fanbois

[Hope Thelps]

It Just Works. As long as you hold it the way Steve Jobs instructs you to. Coming from the supposed experts on user interface this is a major let down. Users holding the phone the way that comes most naturally to them are not wrong - the product is wrong.

Re:Cue the fanbois

[Anonymous Coward]

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:Cue the fanbois

[Idbar]

Apple will also be releasing this new accessory.

Re:Cue the fanbois

[StikyPad]

Grounding, or effectively grounding (by say, shorting two ends of a dipole) an antenna will *always* result in loss of signal, even when starting values are ideal. But regardless of how it was missed, the fact that it was missed at all means one thing: inadequate testing.

Re:Cue the fanbois

[Pojut]

Grounding, or effectively grounding (by say, shorting two ends of a dipole) an antenna will *always* result in loss of signal, even when starting values are ideal.

I think the bigger problem is that with all of Apple's "expertise with hardware", they would design something with this kind of flaw.

Re:Cue the fanbois

[NotQuiteReal]

THEY FIRST told me I HAD to use iTunes, and AT&T,
and I didn't speak up because I wanted to be Cool.

THEN THEY told me I couldn't change the battery,
and I didn't speak up because I buy a new one every year.

THEN THEY told me I had to hold the phone with my pinkie extended,
and I didn't speak up because I don't mind looking gay.

THEN THEY CAME for more of my money
and by that time there was none left to buy more crap.

Apologies to Niemöller.

Re:Cue the fanbois

[Dahamma]

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:Cue the fanbois

[hobo sapiens]

That's not phone. Thats P H O N E, as in Please Hold On Narrow End.

Re:Cue the fanbois

[Guillermito]

Sorry, guys. This is the right way

Cases

[Peach Rings]

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

Re:Cases

[dingen]

Because the case is made out of rubber and runs around the phone, effectively isolating you from the antennas, avoiding the antennas to connect to each other through you.

Re:Cases

[Loomismeister]

The skin connects the front and back antennas through electrical conductivity. If there is a case blocking the connection the problem doesn't happen.

Re:Cases

[wramsdel]

It'll insulate the metallic ring that's "part of the antenna system", which might mean "the antenna" or might mean "some other element that helps the antenna do its work" (i.e. a resonant grounding piece). Antennas are tuned, resonant, structures...think of a tuning fork that needs to oscillate at a certain frequency. Bridging the gap between the two exposed elements changes the electrical characteristics of it such that the antenna becomes detuned and reception is impaired. By applying a case, your hand can no longer come in contact with the ring, so the antenna isn't as severely detuned and the cell phone signal isn't as attenuated. I say "as severely" because there will always be some impact when your hand is in reasonable proximity to the device, but it won't be of the magnitude that direct contact would be.

Re:Cases

[icebike]

Exactly.

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

[yakumo.unr]

So, what they're saying is, all phones suffer from this, apart from any phone that has the aerial behind an insulating layer, such as a plastic case.

Off topic, we're the only phone with the external metalwork acting as the aerial, isn't that awesome.

Don't forget all phones suffer this defect, so it's not a design defect, no really.

Re:Cases

[Gary W. Longsine]

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".

Re:Cases

[cybereal]

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.

Re:Cases

[slimjim8094]

Are you fucking serious?? I hope you don't seriously believe that touching an antenna on a device with few-watt or less output power is dangerous.

First of all, internal antennas are the new part. For the longest time, every cellphone had a telescoping, exposed antenna. You can even still get them, if you want.

Second of all, the phone transmits at an outside maximum of 2W - usually much less. You can literally suck on an antenna broadcasting at 2W and not feel a thing (I've done it)

Third of all, tons of other things that you use all the time transmit over exposed antennas: Old cordless phones, many walkie-talkies, baby monitors... etc. The reason you cover up an antenna has to do with protecting the antenna and, as it happens, protecting it from detuning.

Simply ...

[randyzoch]

1) Stand on one leg, preferably facing the cell tower. 2) Use your other leg to form a crude counterpoise for the iPhone4's various antennas. Also, experiments in dry/low-humidity regions which lead to dry/chapped hands may also contribute to your success making and holding a call. What other company could get away with producing a product like this and succeed?

Uh... Huh...

[MightyMartian]

"For best results, levitate one inch from your ears."

So its really the iPod4?

[phonewebcam]

Worse reception than the iPhone3 - check.
Still tied to the worst US carrier - check.

But hey, facetime is so awesome it overcomes all this...

Realtime video calls which exceed the definition of the human retina? - cheC&&^& >>>>>CARRIER LOST

form over function

[nobodyman]

Of course, apple could have easily designed the phone with with a some plastic along the side, but this would go against their aesthetic "vision". Anyone who has used an Apple mouse (*any* Apple mouse) knows that ergonomics takes a back-seat to physical appearance. Always.

Re:form over function

[dingen]

The reason the case is part of the antenna system is actually to improve reception, because it makes the surface operating as an antenna larger.

When isolated it works pretty well I suppose. But it fails when a user touches all antennas at once, effectively short circuiting the entire system.

Re:form over function

[Luckyo]

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.

Re:form over function

[MichaelSmith]

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:Another person

[hawguy]

I can hold my Android phone any way I want to and I don't see any loss of signal strength, so apparently it *is* possible to design a working phone within current SAR limits...

I wasn't aware that government regulation forced BP to cut corners and undertake a risky well closure strategy, ignoring evidence that the BOP was damaged. Which regulation was that?

"Just avoid holding it that way"

[Chad Birch]

Saw a great post on reddit earlier today where a user goes through a bunch of Apple's own advertising to see how they've shown the phone being held.

Re:"Just avoid holding it that way"

[asdf7890]

Another reddit poster showed the true way to hold an iPhone: http://i.imgur.com/h9UDd.png

Danish professor predicted this

[Namarrgon]

This guy is an expert in antenna design from Aalborg University, and predicted this two weeks ago.

Coating is best idea

[SuperKendall]

They already had the phone inside the case in previous generations, the external antenna does improve the signal. No need to throw the baby out with the bathwater. A light non-conductive coating would work perfectly well.

Re:in addition

[Hurricane78]

Geeks generally don’t buy Apple products. They buy a Linux phone from an obscure company that is also barely usable as a phone, but at least completely hackable.
Hipsters and valley girls buy Apple products. Oh, and those people that drive Priuses. ^^

Presperation triggered

[SuperKendall]

I think the reason they may not have found this in testing, is because it seems that you have to have slightly sweaty hands to trigger the problem. Just after running through an airport I was able to replicate the speed drop, but sitting on the plane a little later I could not see a network speed drop no matter how tightly I gripped the edges.

The tested mostly in winter, now it's summer - leading more people to have this problem.

Re:Presperation triggered

[xs650]

It is a disgrace that it even got to testing, anyone with a clue about RF design would have predicted the dismal performance.

Re:The cure is in the case

[cynyr]

1) buy some broccolii from the store
2) remove and dry off the rubber band
3) place rubberband on iPhone
4) ???
5) PROFIT!(and save like $27, and get some iron)

Re:The media need to call Apple out.

[Jarik C-Bol]

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:Missed? Seriously?

[symbolic]

I don't think this was missed at all. It's like any of the other "defects" that have showed up in Apple products. I'm tempted to believe that Apple knew quite well about this, but decided to go with it anyway because a) fixing it would involve removing some of the "sleek" factor and b) they knew that there would be such mass hysteria over acquiring the new product that it wouldn't matter - at first. It's all about taking calculated risks.

That having been said, it's precisely this attitude that destroyed my fan loyalty several years ago- I simply got tired of being bent over by Apple's marketing prowess. I still buy an Apple product every now and then, but the days of drooling all over myself at the mere mention of a new Apple product are LONG gone.

Re:It may have been

[hobo sapiens]

"
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:The only 'fanbois' I see are mindless droids...

[catmistake]

Please tell me where I can touch my Nexus One (with a single finger, mind you) that will cause it to drop a call. Calling this a nonissue is moronic.

shows you in the manual

see page 6, moron

Re:Missed? Seriously?

[sqrt(2)]

I'm pretty sure that's why they designed the bumper accessories to be the way they are. They turned a product defect into a way to sell an overpriced accessory to fix their devices shortcomings - and it's working! The Jobsian management style never ceases to amaze me with its outcomes.