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.

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

[antibryce]

the problem comes about when your hand shorts the two metal bits together. Put a case on them and you won't short them.

Re:The cure is in the case

[Anonymous Coward]

You forgot to mention it's a $29 rubber band.

"Just avoid holding it that way"

[Chad Birch]

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

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

[nobodyman]

Another believable theory I've heard is that the "fake 3gs" cases that they used to disguise the prototype units meant that this problem wasn't caught during field testing.

Re:Nothing to see here

[bbahner]

If the phone has signal issues in real world use your point is valid. I haven't seen real world issues with mine yet - but we shall see. I suspect if this is really a problem Apple will do something about it - they're certainly profitable enough to do a replacement program. It would certainly be less expensive than the fallout of a yearlong debacle with their primary product. It is telling that in this thread someone marked my prior comment as a troll (really??) Seems to me there is plenty in this stream that is quite a bit more inflammatory than that. Slashdot certainly has a 'point of view' ..

Re:Coating is best idea

[m2shariy]

A light non-conductive coating would work perfectly well.

May I suggest duct tape? There is nothing duct tape cannot fix!

Re:If it affects "every wireless phone"...

[dingen]

Because it's bullshit. No other phone has a conductive casing with the antennas attached to it. Now we know why.

Re:Cue the fanbois

[Gazoogleheimer]

At the RF frequencies involved, you're a lot more conductive than at, say, low-voltage DC.

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.

Re:Cue the fanbois

[isilrion]

Actually, that's L from the movie [wikipedia.org].

Re:Cue the fanbois

[Guillermito]

Sorry, guys. This is the right way [boston.com]

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 [htc.com]

see page 6, moron

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

[CrazyChinaman]

Putting your finger there may attenuate the signal. But it won't short the antenna. My antenna is internal. I can't even take the backplate off and short it. Once I get home, I'll do some speed tests for ya if you like, but right now, I'm in a huge concrete box. BTW, that's an Incredible...he did ask for an N1 death-point ;)

Re:Cue the fanbois

[IICV]

It's okay, he's just cosplaying a douchebag.

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

[catmistake]

but right now, I'm in a huge concrete box

You mean there are places where you don't get ideal reception? Huh. Sucks for you I guess. And everyone with a cell phone. Yes, newsflash, in poor cell areas you. may loose calls. Try finding that death touch when you're sitting under a tower. This is such utter garbage it's ridiculous... in the face of SCIENCE telling you there is nothing wrong... the multitudes that still believe ... incredible

Re:This is 100% Apples fault

[IrrepressibleMonkey]

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.

That's not being universally reported. Did you read all of the articles? Read through the PCMag (second link) - that's not what is being reported there. Yes, the problem could be affecting all iPhone 4 handsets, but it's certainly not affecting all iPhone 4 users. Theories are flying around about hand sweat, local signal strength and even GSM bandwidth as contributing to the size of the problem.

All of the YouTube fault demonstrations I have seen have shown users holding the phone unusually firmly, with the ball of the hand coming right around to the front of the phone (even to the point of partially obstructing the screen). This isn't how most people hold their phone - although I accept that some might. Ars Technica http://arstechnica.com/apple/news/2010/06/new-iphone-4-antenna-causing-potential-reception-issues.ars [arstechnica.com] posted some preliminary investigation claiming no issues when holding the phone "normally", but proving the issue when dampening their hand and adopting the "death grip".

So yes, there is an issue, but your mileage may vary. It may not require the level of hysteria that has been reached in certain media outlets.

Interestingly, this may actually be a combination of issues as the same symptoms have been demonstrated on the 3G and 3GS in the "death grip" and neither has an external antenna. Similar issues have been reported on the Nexus 1 and Palm Pre - you can find some links off this article: http://arstechnica.com/apple/news/2010/06/jobs-on-iphone-4-antenna-avoid-holding-it-in-this-way.ars [arstechnica.com]

I don't want to dismiss anyone's fears. I'm still uncertain as to whether I'll purchase an iPhone 4 myself, but I doubt the scenario that you describe is being experienced by the majority of IPhone 4 users.