Technical explanation on iPhone 4 Antenna issue

[Mliii]

Nobody seems to recall the first TiBook in 2004. Similar story there. Only it was the titanium case shielding the WiFi signal.
Apple got out of this one without exchanging any of these laptops.

Not only do I remember that, I still use that laptop. The antenna is taped to the Titanium body of the bottom frame of the computer. As time went by, the antenna tape disconnected from the Titanium body making a bad signal situation worse. There was NEVER a formal fix, but I do remember Steve gleefully announcing the "FIX" when the next generation was delivered by sanctimoniously announcing that the antenna was moved to the top of the newly designed case "where it always should have been!" 😉 Hilarious given his interventionist personality and a model for what we can expect when the next iPhone comes out!
Oh, and I don't lose *much* signal but won't go so far as to say I don't have a problem with it.🙂

 

[zephxiii]

Just got my iP4 today. I haven't really done enough testing yet, but I think reception is probably better than previous models.....IF you aren't touching the antenna. So far my only test has been down in my living room where signal is pretty weak. The iP4 has lost 3G and bounced to 850mhz GSM 3 times now while holding it (not intentionally) in a way that degrades RF performance.

The problem is though......that my 3GS has NEVER done that there, it always held onto 3g with no problems.

Note: When I say bounced to 850mhz GSM, this is completely losing signal, searching, then picking up the other GSM network that has not been integrated into native AT&T network yet. So it's pretty much completely losing signal and roaming onto former Centennial. My 3GS has never done this since the 850mhz 3g overlay was launched.

 

[zephxiii]

Well I bought a case for it, just some nice cheap little silicon case at best buy. I can tell you that it has made reception down in my living room better and it hasn't lost 3G connection yet with it. Seems to be on average about a bar better than before.

"Brilliant" antenna design lol....when you have a case installed lol.

 

[tivoboy]

no question

There is NO question, the reception on the iphone 4 is better than the iphone 3,

unless one touches the side, then it is worse.

but, it gets signal in areas where the others couldn't, holds them better and I THINK has been consistency (not necessarily sound quality) than the 3 or 3gs.

Just cover that bottom left area, or use a case. Otherwise, it is pretty poor IMHO. Drops calls a lot

 

[shandyman]

The defining factor with this issue will heavily rely on demographics. If you live in a major city, with a relatively new tower infrastructure, the effects of the antenna may be negligible enough as to not compromise communication. But if you are living in a smaller demograph, with older infrastructure, this issue may be significant enough to cause periodic (if not complete) disruption in communication.

For the record I am not trying to bash the iPhone, I own one. I am just dumbfounded as to how they could allow an antenna design such as this to pass a design review. I was anxiously anticipating an iPhone 4 upgrade myself, but this recent influx of issues has put me on the sideline.

I hope they are able to effectively resolve this issue in a timely fashion.

if it's a flaw with all of the iPhone 4's, how come when testing mine and my neighbours iPhone 4's at the same time in the same spot in about 4 or 5 different spots did my iPhone never lose any signal but his dropped a couple of bars? both running the same firmware and everything. That just shows it's a flaw with SOME iPhone 4's, not all.....

 

[zephxiii]

if it's a flaw with all of the iPhone 4's, how come when testing mine and my neighbours iPhone 4's at the same time in the same spot in about 4 or 5 different spots did my iPhone never lose any signal but his dropped a couple of bars? both running the same firmware and everything. That just shows it's a flaw with SOME iPhone 4's, not all.....

IT IS a flaw, and it's by design, which affects ALL iphone 4s. Your friend's phone could have been on a different cell/sector that was weaker, or whatever the variable. The best way to test it is when you are around 1-2 bars on 4.0.1 and higher.

To deny that it affects all phones because it is by design, is well silly. I just know that if you want your antenna to work the best, you need a case to keep you from touching it. It has definitely helped on my brand new iphone4.

 

[shandyman]

IT IS a flaw, and it's by design, which affects ALL iphone 4s. Your friend's phone could have been on a different cell/sector that was weaker, or whatever the variable. The best way to test it is when you are around 1-2 bars on 4.0.1 and higher.

To deny that it affects all phones because it is by design, is well silly. I just know that if you want your antenna to work the best, you need a case to keep you from touching it. It has definitely helped on my brand new iphone4.

they were in the exact same position, on the same mobile phone network, a matter of a minute between each test, so really would be small variable. we tested it in various areas, some with full signal, some with 1 or 2 bars, no bumpers in use. his dropped bars, mine did not. ergo, it's a falt that does not affect all phones, just some.

so you're either in denial or just ignorant....

 

[zephxiii]

they were in the exact same position, on the same mobile phone network, a matter of a minute between each test, so really would be small variable. we tested it in various areas, some with full signal, some with 1 or 2 bars, no bumpers in use. his dropped bars, mine did not. ergo, it's a falt that does not affect all phones, just some.

so you're either in denial or just ignorant....

No, you just don't get it, or you are doing it wrong and don't understand wireless. I don't get how you don't understand that an antenna designed into the exposed metal band will attenuate when touched which is a problem by design and is something any RF engineer will tell you and will affect all phones. Ignoring that reality is plain dumb.

http://www.anandtech.com/show/3794/the-iphone-4-review/2

Of course, the caveat is that as with all external antennas, the potential for both unintended attenuation and detuning is much, much greater. When I first saw the iPhone 4's design spelled out watching the keynote online, I immediately assumed that Apple was going to apply an insulative coating atop the stainless steel. Perhaps even use diamond vapor deposition (like they did with the glass screen atop the iPhone 3GS) to insulate the stainless steel from users. We now know rather definitively that this isn't the case. Of course, the result is that anything conductive which bridges the gap in the bottom left couples the antennas together, detuning the precisely engineered antennas. It's a problem of impedance matching with the body as an antenna, and the additional antenna that becomes part of the equation when you touch the bottom left.

The fact of the matter is that cupping the bottom left corner and making skin contact between the two antennas does result in a measurable difference in cellular reception. But as we'll show, RF is a strange beast.

 

[caige]

I live in the Chicago area and although I have not really had a problem with dropping calls even with only one bar showing, I have noticed that if I turn off 3G my signal strength improves dramatically. Even without the bumper I get as many as 4 bars. With the bumper I get all 5 bars. I don't know what is the significance of turning off 3G but it works for me. 3G in not really needed for making and receiving calls. Maybe some of you who are more knowledge in this area have an explanation for this phenomena.

 

[shandyman]

No, you just don't get it, or you are doing it wrong and don't understand wireless. I don't get how you don't understand that an antenna designed into the exposed metal band will attenuate when touched which is a problem by design and is something any RF engineer will tell you and will affect all phones. Ignoring that reality is plain dumb.

http://www.anandtech.com/show/3794/the-iphone-4-review/2

lol so doing exactly the same thing in the same way with 2 iPhones, holding in exactly the same way, how can i be doing something wrong...

must be nice in your world where you're right and everyone is wrong despite the evidence to the contrary.............

 

[zephxiii]

I live in the Chicago area and although I have not really had a problem with dropping calls even with only one bar showing, I have noticed that if I turn off 3G my signal strength improves dramatically. Even without the bumper I get as many as 4 bars. With the bumper I get all 5 bars. I don't know what is the significance of turning off 3G but it works for me. 3G in not really needed for making and receiving calls. Maybe some of you who are more knowledge in this area have an explanation for this phenomena.

Well comparing GSM to 3G is comparing two different wireless networks. GSM on average operates at higher power level than 3G, and does not suffer from "cell breathing" (cell area shrinkage) from increased channel noise from a lot of active users. As a result of this GSM will appear to penetrate stronger and reach further than 3g.

Even though 3g may come off weaker in signal strength, as long as you consistently have a good connection, you should be fine.

 

[zephxiii]

lol so doing exactly the same thing in the same way with 2 iPhones, holding in exactly the same way, how can i be doing something wrong...

must be nice in your world where you're right and everyone is wrong despite the evidence to the contrary.............

Must be nice to ignore the reality, even though you may not see it. You're still going to try and tell me signal does not attenuate when you touch the exposed metal antenna (especially when bridging the gap which has the most affect)? Please LOL I'll do it to any and all iphone4s.

 

[shandyman]

Must be nice to ignore the reality, even though you may not see it. And for god sakes i hope both phones are on the same carrier.

as stated both phones were on same carrier, did you not even read? lol. how am i ignoring the reality when my phone did not drop a bar, but my neighbour's did when tested with me holding them in the precisely same location doing the same thing. the only difference was a matter of seconds inbetween testing mine then his.............. the difference in handsets was his was a launch one and mine was a week 28 model. but i spose you're just going to ignore my evidence since you just have to be right...

 

[caige]

Well comparing GSM to 3G is comparing two different wireless networks. GSM on average operates at higher power level than 3G, and does not suffer from "cell breathing" (cell area shrinkage) from increased channel noise from a lot of active users. As a result of this GSM will appear to penetrate stronger and reach further than 3g.

Even though 3g may come off weaker in signal strength, as long as you consistently have a good connection, you should be fine.

Thanks for that explanation. But what is GSM?

 

[zephxiii]

Thanks for that explanation. But what is GSM?

GSM is the network you are using when are not using 3g, it is represented by the E in place of the 3G on your phone.

 

[zephxiii]

as stated both phones were on same carrier, did you not even read? lol. how am i ignoring the reality when my phone did not drop a bar, but my neighbour's did when tested with me holding them in the precisely same location doing the same thing. the only difference was a matter of seconds inbetween testing mine then his.............. the difference in handsets was his was a launch one and mine was a week 28 model. but i spose you're just going to ignore my evidence since you just have to be right...

And mine is a week 41, just got it yesterday, and you know what? It doesn't matter as touching an exposed metal antenna attenuates signal strength (especially when bridging the gap), and that's a design problem, and all these iphone4s have the same damned antenna design.

 

[caige]

GSM is the network you are using when are not using 3g, it is represented by the E in place of the 3G on your phone.

Thanks again. So for those people who are having signal problems they should just use GSM and stop complaining about loss of signal strength.

 

[shandyman]

And mine is a week 41, just got it yesterday, and you know what? It doesn't matter as touching an exposed metal antenna attenuates signal strength (especially when bridging the gap), and that's a design problem, and all these iphone4s have the same damned antenna design.

all that proves is that some have the problem and some don't. there are others on this forum that have done the same thing as me with same results. you're just showing yourself to be ignorant and just want to say everyone else but you is stupid and wrong. way to win your argument.... lol.

 

[zephxiii]

Thanks again. So for those people who are having signal problems they should just use GSM and stop complaining about loss of signal strength.

Well, its only really a problem if you are handling it naked and happen to be in the right situation (fringe area) and happen to hold it in a way which attenuates the signal enough to cause problems.

In the case for me in my living room, handling it naked and holding it certain ways would cause it to lose 3g signal all together, whereas 3GS would always hold onto the signal no matter what.

After putting the iphone4 into a case, I haven't had an attenuation problem as it keeps me from touching the metal antenna (attenuates a little bit), or bridging that gap (attenuates a lot more).

But I think the 4 in a case will outperform my 3GS, it seems to be so far.

 

[AZREOSpecialist]

Why are we still talking about this? Return your iPhone if you have trouble. Nobody is holding a gun to anyone's head forcing them to keep or even own an iPhone. There are plenty of other options out there. 😉

 

[zephxiii]

all that proves is that some have the problem and some don't. there are others on this forum that have done the same thing as me with same results. you're just showing yourself to be ignorant and just want to say everyone else but you is stupid and wrong. way to win your argument.... lol.

I think you're having the problem with argument losing. I know I haven't lost ****, its just fun watching you ignore reality as I fully understand what's going on with these phones, and to be honest you're probably either lying about your results, or there is a difference between early and later models.

The difference between the two being that later models do not attenuate as much as early models (and i'm willing to believe that), but that does not change the fact that it still attenuates as I am seeing it in a week 41.

In the end though, touching an exposed metal antenna attenuates the signal strength.

 

[shandyman]

I think you're having the problem with argument losing. I know I haven't lost ****, its just fun watching you ignore reality as I fully understand what's going on with these phones, and to be honest you're probably either lying about your results, or there is a difference between early and later models.

The difference between the two being that later models do not attenuate as much as early models (and i'm willing to believe that), but that does not change the fact that it still attenuates as I am seeing it in a week 41.

In the end though, touching an exposed metal antenna attenuates the signal strength.

the fact is that doing the precise same tests on 2 different iPhones, one visibly dropped signal the other didn't. other people on this forum have done their own tests with the same results. so you're wrong.

 

[samcraig]

they were in the exact same position, on the same mobile phone network, a matter of a minute between each test, so really would be small variable. we tested it in various areas, some with full signal, some with 1 or 2 bars, no bumpers in use. his dropped bars, mine did not. ergo, it's a falt that does not affect all phones, just some.

so you're either in denial or just ignorant....

as stated both phones were on same carrier, did you not even read? lol. how am i ignoring the reality when my phone did not drop a bar, but my neighbour's did when tested with me holding them in the precisely same location doing the same thing. the only difference was a matter of seconds inbetween testing mine then his.............. the difference in handsets was his was a launch one and mine was a week 28 model. but i spose you're just going to ignore my evidence since you just have to be right...

I know you're really stubborn Andy as proven in other threads. But the reality is - that you can't prove you and your friend were getting a signal from the same tower during your experiment. I'm not arguing for or against a design flaw or not.

I am simply stating that unless you have a deep dive diagnostics - you can't just say you have the same phone, os, location and carrier. Because it's VERY possible that you're locked into one tower and your friends phone is locked into another. Especially in locations that have LOTS of towers.

my .02

 

[shandyman]

I know you're really stubborn Andy as proven in other threads. But the reality is - that you can't prove you and your friend were getting a signal from the same tower during your experiment. I'm not arguing for or against a design flaw or not.

I am simply stating that unless you have a deep dive diagnostics - you can't just say you have the same phone, os, location and carrier. Because it's VERY possible that you're locked into one tower and your friends phone is locked into another. Especially in locations that have LOTS of towers.

my .02

oh look, its you again following my posts just to argue with me. jog on lol.

 

[samcraig]

oh look, its you again following my posts just to argue with me. jog on lol.

Enjoy your paranoid fantasy there. As the person who emailed Steve Jobs and got the response "just try holding it differently" - this subject is of definite interest to me DESPITE you posting about it.