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It looks like Apple needs to hire some new antenna engineers

Moleculo

Moleculo

Ham Radio Nerd
Apr 14, 2002
9,200
1,686
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I read this problem today with the new iPhone, which has an external antenna that if you touch or hold the antenna in a way that closes the gap on the external antenna, the phone suddenly loses signal. Apparently, it's very reproducible: iPhone 4 Loses Reception When You Hold It By The Antenna Band?. Guessing purely from the looks of the iPhone, it seems like it's just a basic loop antenna, although it's difficult to tell what's going on inside. If it really is a loop, it makes you wonder who the bonehead was that designed an antenna on a RF device that lets the user short the thing out by closing feed point with their hands? :oops:
 

email received
July 2, 2010

Letter from Apple Regarding iPhone 4

Dear iPhone 4 Users,

The iPhone 4 has been the most successful product launch in Apple’s history. It has been judged by reviewers around the world to be the best smartphone ever, and users have told us that they love it. So we were surprised when we read reports of reception problems, and we immediately began investigating them. Here is what we have learned.

To start with, gripping almost any mobile phone in certain ways will reduce its reception by 1 or more bars. This is true of iPhone 4, iPhone 3GS, as well as many Droid, Nokia and RIM phones. But some users have reported that iPhone 4 can drop 4 or 5 bars when tightly held in a way which covers the black strip in the lower left corner of the metal band. This is a far bigger drop than normal, and as a result some have accused the iPhone 4 of having a faulty antenna design.

At the same time, we continue to read articles and receive hundreds of emails from users saying that iPhone 4 reception is better than the iPhone 3GS. They are delighted. This matches our own experience and testing. What can explain all of this?

We have discovered the cause of this dramatic drop in bars, and it is both simple and surprising.

Upon investigation, we were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong. Our formula, in many instances, mistakenly displays 2 more bars than it should for a given signal strength. For example, we sometimes display 4 bars when we should be displaying as few as 2 bars. Users observing a drop of several bars when they grip their iPhone in a certain way are most likely in an area with very weak signal strength, but they don’t know it because we are erroneously displaying 4 or 5 bars. Their big drop in bars is because their high bars were never real in the first place.

To fix this, we are adopting AT&T’s recently recommended formula for calculating how many bars to display for a given signal strength. The real signal strength remains the same, but the iPhone’s bars will report it far more accurately, providing users a much better indication of the reception they will get in a given area. We are also making bars 1, 2 and 3 a bit taller so they will be easier to see.

We will issue a free software update within a few weeks that incorporates the corrected formula. Since this mistake has been present since the original iPhone, this software update will also be available for the iPhone 3GS and iPhone 3G.

We have gone back to our labs and retested everything, and the results are the same— the iPhone 4’s wireless performance is the best we have ever shipped. For the vast majority of users who have not been troubled by this issue, this software update will only make your bars more accurate. For those who have had concerns, we apologize for any anxiety we may have caused.

As a reminder, if you are not fully satisfied, you can return your undamaged iPhone to any Apple Retail Store or the online Apple Store within 30 days of purchase for a full refund.

We hope you love the iPhone 4 as much as we do.

Thank you for your patience and support.

Apple



Press Contacts:
Natalie Harrison
Apple
harri@apple.com
(408) 862-0565
Steve Dowling
Apple
dowling@apple.com
(408) 974-1896
Click to expand...
 
I'm glad that the IPHONE will be with Verizon in 01/2011. Until then, I'll wait.. ATT pretty much sucks for coverage.. :)
 
Check this out from Anantech:

dd3v33sr_169ch3mkvf8_b.jpg


So here's the actual antenna design - not a loop but two seperate antennas. If you put your finger over the bottom left, you short out the two antennas, which will obviously change it's resonance.
 
Apparently the concept of having antennas on the outside perimeter of phone is new idea, and not all that well thought out yet it seems. Competitive pressures are high, considering the quality of the latest phones coming from HTC.

Of more interest to radio buffs is the BCM4329 wifi chip used in most of the latest phones.
Apparently it has an FM broadcast receiver and FM transmitter, possibly capable of operation down to 76MHz. Broadcom is not forthcoming on datasheet for the chip, but if the control protocol can be reverse engineered, perhaps we could have a walkie-talky of sorts in the 76-88MHz band. That is, only if the appropriate hardware connections are made in the phone.
 
moleculo said:
Check this out from Anantech:

dd3v33sr_169ch3mkvf8_b.jpg


So here's the actual antenna design - not a loop but two seperate antennas. If you put your finger over the bottom left, you short out the two antennas, which will obviously change it's resonance.
Click to expand...

I've never had one of these in my hands but it appears they're using this antenna in a dual roll, as a trim piece first, antenna 2nd.
 
Just saw a blurb about this on tv last night, and it appears that Jibs cure for the problem is to give any owner who asks a free rubber band type of cover that goes around the outside perimeter of the phone.

By the way, I just love the "we miscalculated the way the bars are displayed" answer. :laugh:
 
Google and Motorola are loving this. Android X released on Thursday and sales are through the roof.
My son has the Android, my Android X will be here on Monday.
My daughter has the iPhone so I have been able to compare them side by side.
Droid is the way to go as far as I am concerned.
 

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