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But, as other people with more experience in antenna design have already posted, it is extremely unlikely that someone has crammed a "better" antenna into the back of a cell phone case.

Even then better is relative, a better FM antenna in my car is omnidirectional. A better TV antenna in my house is high gain and directional with a rotor. I would assume Apple designs the iPhone antenna to be omnidirectional with the elevation angles best suited for common orientations of the phone (i.e. all actually antennas are somewhat directional, we just calculate the value against a perfect theoretical isotropic antenna). It's certainly plausible they have designed a case that could increase the gain in certain directions and orientations but the direction variable is just not possible for them to account for.
 
I'm actually a former apple antenna engineer

Are you the guy that designed the iPhone 4 antenna that was detuned by touching the bare metal exposed antenna, and bridging the multiple external antennas that caused signal dropouts and caused Mr. Jobs to famously say 'you're holding it wrong'?

If so, I guess that's why you're a "former" Apple antenna engineer. :p

I kid, I kid...
 
So the company which independently verified these claims knows less about what is "scientifically possible" than you?

And no, CETECOM will not jeopardize their reputation to make some money and claim that something works if it doesn't. If they did, they'd be out of business tomorrow. I've worked with CETECOM, because I work in mobile phone development (unlike all the "experts" here who claim this can't work), and CETECOM doesn't sell positive results. So if you believe that this doesn't work, your first big task is to explain how CETECOM verified these claims.

Then they should post the CETECOM results and testing methodology.

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While I might agree there is little or no benefit to this product that statement is so wrong.

When you install an antenna on your house and run a co-ax cable to your TV or FM receiver which part of that is not passive?

A larger antenna is a larger antenna/collector, not a passive add-on.
Running coax from the antenna to the house instead of a wire pair doesn't increase signal strength, it decreases attenuation/loss of signal and noise.

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You may be right, I don't know the physics of it, but I can extend the signal range that my car plipper works by placing the plipper next to my head to make it work at distances it would not work if I take it away from my head. So surely it must be using my body as an antenna extension?

You're probably experiencing reflection. Try putting your head between the car and the "plipper" and you'll probably decrease range.
 
So you're saying that you CAN increase signal strength passively, just not in this way, right? If you've got the right shape and size of antenna, you should be able to. At least I've always seen it work with my TV, radio, and wifi station.

No, I just didn't want to write a dissertation on radiators, signal to noise, and other radio topics so I was too brief.

You can focus a signal of given strength so that more signal is directed at the antenna of the main system. A large enough reflector will (in a mobile device such as a phone) block the antenna just as often as it focuses more signal at it. A flat reflector is minimally effective, you want a properly curved reflector that focuses reflected signal at the main antenna. And tracks the cell tower and cellphone, constantly adjusting angle to keep them focused on each other.

When you start reflecting signals you start running in to distortion, multi-path and other signaling issues that may or will counteract the extra radiation directed at the antenna and will probably degrade overall call quality.

Angle of incidence = angle of reflection. So this thing should only, theoretically, reflect an extra "signal" of the size of the built-in antenna. That reflected signal will arrive at the antenna slightly after the antenna received the directly transmitted signal. That does not mean you doubled signal reception strength.

All that aside, there's this:
A cell phone to cell tower conversation is two ways. If this thing is absorbing signal that would otherwise have missed the phone's antenna and focusing it at the phone's antenna then it must, in reverse, also be absorbing the cell phone antenna's output signal and diffusing it over the larger area of the "booster" and spreading it out more so the cell tower can't hear the phone as well.
I mean... how is this thing focusing/amplifying output from the phone?

I know this is America and in this country we always think "bigger is better", "more is better", but when dealing with antennas there are physics involved that dictate antenna size. Simply adding more antenna will not necessary make things better.
 
I know that on-roof TV antennas are very old and 20th century, but they (and others) amplify signals coming in, and could amplify signals going out.

No. That's not how they work. Those antennas on the roof collect more energy because they are *physically larger* elements than the rabbit ears on an old tv set. However, we need to back up: these iPhone cases are not even antennas. They are simply playing games with impedances and not having a significant impact on overall performance. In fact, all of this reminds me of a very famous TV antenna scam from the 1980's:

GFX-100-dish-antenna1.jpg


People really thought they were buying a miniature satellite antenna that would boost their performance!! I guess there is still an untapped market of people who haven't the slightest inkling of electromagnetics or antenna theory that will by cr@p like this. I stand by my original statement that these devices are a rip off.
 
You can affect received signal strength without physically touching the existing antenna through parasitic elements and reflectors.

Yes. However, doing so is going to rob Peter to pay Paul in most cases. You might be able boost gain around a particular direction or over a narrow range of frequencies. But performance will suffer in other directions and other frequencies, in turn reducing the frequency (as well as spatial) bandwidth of the iPhone, resulting in lower overall performance.

I seriously doubt that the developers of this piece of junk did any rigorous measurements in an anechoic chamber.
 
Remember the old pringles can wifi antenna modifiers? They worked.

The pringles can or cantenna worked because u had to direct your device towards the source of emission or direct the source of emission towards the device. This scenario works well for fixed devices.
 
I know that on-roof TV antennas are very old and 20th century, but they (and others) amplify signals coming in, and could amplify signals going out.

Not old, actually new. Once the over-the-air TV went 100% digital, lots of places lost reception and only worked with antennas mounted on the roofs. And analog TV at least worked with degraded quality when reception was bad, but digital TV seems to either work perfectly or jump so much that it's unusable. We had to stick an antenna on our roof.
 
No. That's not how they work. Those antennas on the roof collect more energy because they are *physically larger* elements than the rabbit ears on an old tv set.

Sorry, but you're wrong. Read all the other postings by people who have some knowledge of antennas. Physically larger has nothing to do with it -- the positioning and size of the elements (re. wavelength) have to do with it.

This should clarify things for you:

http://en.wikipedia.org/wiki/Yagi-Uda_antenna
 
How about this argument. Apple spent how many billions of dollars on R&D for the iPhone 6 and has been through how many revisions and if this device worked apple didn't build something similar in?

does the size of the antenna matter? If apple made a thicker phone (5s/4s thickness) would that make the reception better?
 
Maybe with this brand new state of the art break through technology; the iPhone will be able to have AM/FM radio inside future iPhones.

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Not old, actually new. Once the over-the-air TV went 100% digital, lots of places lost reception and only worked with antennas mounted on the roofs. And analog TV at least worked with degraded quality when reception was bad, but digital TV seems to either work perfectly or jump so much that it's unusable. We had to stick an antenna on our roof.

Have you try a flat sheet HDTV antenna? I made several purchases of different size sheets and discover the smallest and cheapest model worked the best. I even purchase the Leaf @ $40 but the $10 Supersonic just as good and was only 4 X 8 inches; much smaller then the Leaf.
 
Have you try a flat sheet HDTV antenna? I made several purchases of different size sheets and discover the smallest and cheapest model worked the best. I even purchase the Leaf @ $40 but the $10 Supersonic just as good and was only 4 X 8 inches; much smaller then the Leaf.

Yes, that wasn't nearly enough. It was almost good enough for my grandma's house but still not enough. We tried three different ones, I forget which, two of them with active amplifiers.
 
I'm all for a nice D3O case, and given how many times I drop my iPhone, I've forever grateful for my Tech 21 and Zagg combo.

But this kinda also reminds me of the old "CD Rings" that were supposed to induce better audio quality after you stuck them to the outside of a CD. Or maybe, green pen, anyone?
 
The higher the price the stronger the placebo affect.

As much as I would love this case to work as advertised, I have the strongest feeling that Placebo is basically how it works. It seems have generated quite a buzz on the web, so hopefully it'll get put to the scientific metal very soon.
 
You can NOT increase signal strength passively. You may be able to focus signal from a larger area to a smaller area but the shapes required are not present in this product.

Here's the tell: Nowhere on their web site do they talk about an average db increase of signal or S/N ratio.
Want further proof: look around in Amazon for any of the other snake-oil stick-on antenna boosters. Notice they almost all have 2 star reviews. Why? they don't work. They can't work.

I'll save you $50: put a $10 case on your phone. Line the inside of the case with a piece of aluminum foil that you've drawn some "T" shapes on.

So what you are saying is passive antennas cannot have a positive gain and passive transponders do not exist. "Interesting" As the linguistically gifted George W. Bush would say, you are “misunderestimating” the nature of passive antennas.
 
Mine arrived, and having used it I can say that I hadn't really seen much of a difference given my environment .

It's a very nice case.

Not worth the cash though imho.
Secondly it is so tight that my phone slightly deformed when uninstalling it.

Good case, not worth the price.
 
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