Feeds

iPhone 'Death Grip' effect is real, plastic cases don't help

UK boffinry suggests external antenna not clever

High performance access to file storage

The so-called 'death grip' effect, in which a user's hand touching a smartphone antenna degrades its radio connections - a major issue for the iPhone 4 with its external antennae - is real and is a serious problem, according to British boffins researching the matter.

Furthermore they found that plastic insulation between hand and metal has no useful effect - so that "bumper" case may be a completely pointless addition.

The new boffinry comes from the Centre for Communications Research at Bristol uni. The centre's Professor Mark Beach is an expert in the engineering of MIMO (multiple input multiple output, aka multi-element or "smart") antennae, nowadays de rigueur in modern smartphones enabled for various kinds of cell and Wi-Fi networking.

The prof and his colleagues examined the performance of MIMO antennae in various circumstances: with the signal obstructed by a user's hand as one might see in any smartphone, then with the antenna actually in contact with a "thumb phantom" with the same dielectric properties as human skin. Finally performance was examined under the circumstances of handsfree operation, with no inconvenient flesh-sacks nearby.

According to a Bristol uni statement accompanying the research:

The results from the study indicate a 100-fold reduction in sensitivity of the device when held, or when the user’s thumb is mimicked by phantom material.  This de-tuning of the antenna was found not to significantly alter the shape of the radiation pattern, but dramatically worsened the electrical match between the antenna and the electronic circuitry.

“Antenna position and user grip on smartphones may lead to obstruction of radio signal paths and antenna detuning," confirms Beach. It appears that you can perfectly well muck up the performance of any modern smartphone by enclosing it in your hand, but actually touching the antenna offers a further opportunity for trouble.

The famous 'death grip' or 'antennagate' brouhaha which emerged following the debut of the iPhone 4 - which is pretty hard to use without touching its antennae - has now largely died down. At the time, the only solution offered by Apple (other than software fixes) was to wrap the handset in a plastic insulating "bumper".

What do Beach and his colleagues have to say to that?

Well, according to the Bristol uni statement:

Further tests concluded that providing a gap between the antenna surface and the phantom thumb using a layer of plastic electrical insulator did not restore the matching and operational sensitivity of the phone for the antennas under evaluation. Thus, some phone covers in the market place may not improve the situation.

That said, the "bumper" advice from Apple may not have been totally wrong: the iPhone 4 also had an additional problem with a gap between two external antennae being bridged by a user's hand, something that hasn't been investigated here.

Meanwhile Beach and his crew are looking at ways around the issue. The prof says that the CCR at Bristol is working on “automated re-tuning of the antenna elements" which might change the technical landscape in future.

Full details on the research are available here for subscribers to the IEEE journal Antennas and Wireless Propagation Letters. ®

High performance access to file storage

More from The Register

next story
Report: Apple seeking to raise iPhone 6 price by a HUNDRED BUCKS
'Well, that 5c experiment didn't go so well – let's try the other direction'
Video games make you NASTY AND VIOLENT
Especially if you are bad at them and keep losing
Microsoft lobs pre-release Windows Phone 8.1 at devs who dare
App makers can load it before anyone else, but if they do they're stuck with it
Zucker punched: Google gobbles Facebook-wooed Titan Aerospace
Up, up and away in my beautiful balloon flying broadband-bot
Nvidia gamers hit trifecta with driver, optimizer, and mobile upgrades
Li'l Shield moves up to Android 4.4.2 KitKat, GameStream comes to notebooks
Gimme a high S5: Samsung Galaxy S5 puts substance over style
Biometrics and kid-friendly mode in back-to-basics blockbuster
AMD unveils Godzilla's graphics card – 'the world's fastest, period'
The Radeon R9 295X2: Water-cooled, 5,632 stream processors, 11.5TFLOPS
Sony battery recall as VAIO goes out with a bang, not a whimper
The perils of having Panasonic as a partner
NORKS' own smartmobe pegged as Chinese landfill Android
Fake kit in the hermit kingdom? That's just Kim Jong-un-believable!
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.