Breakthrough Promises Smartphones that Use Half the Power

Dupple writes in with news about a discovery that should extend the life of your battery in the near future. "Powering cellular base stations around the world will cost $36 billion this year—chewing through nearly 1 percent of all global electricity production. Much of this is wasted by a grossly inefficient piece of hardware: the power amplifier, a gadget that turns electricity into radio signals. The versions of amplifiers within smartphones suffer similar problems. If you've noticed your phone getting warm and rapidly draining the battery when streaming video or sending large files, blame the power amplifiers. As with the versions in base stations, these chips waste more than 65 percent of their energy—and that's why you sometimes need to charge your phone twice a day. It's currently a lab-bench technology, but if it proves itself in commercialization, which is expected to start in 2013—first targeting LTE base stations—the technology could slash base station energy use by half. Likewise, a chip-scale version of the technology, still in development, could double the battery life of smartphones."

Comments

Call the statistics police

[mattr]

Why do I not believe that 1% of global electrical production goes to powering wireless base stations.

Re:Call the statistics police

[Decker-Mage]

Probably due to the fact that all of IT consumes about 1% of all power globally. And notice in that statistic "about" which, if it comes above 0.0000...01% somehow gets magically gets rounded up (apparently using ceil (APL) function rather than a real rounding function). If they really want to save power generated capacity, they really should look at replacing all those power bricks out there with something remotely efficient before thinking about the power consumption drawn from an, also admittedly, inefficient battery, on the way to the power amps.

Matters not much, methinks, as no one is going to take advantage of the new designs until (1) they are incorporated into "stock" parts and (2) they are cheaper than the designs they are replacing. Almost forgot, and no one is still running a fire sale on the old chips.

Articles like these, long on promise, short on economics, or long on threat, and short on the same thing, economics, piss me off.

Re:Not another one...

[Scytheford]

Too bad the article has nothing to do with battery technology, and you look a fool.

What technology? Who built it?

[complete loony]

If you're just going to pick a few sentences out of the article, you should at least talk about "who" and "what". All we've been left with in the summary is "problem description" and "hype"

Please keep me warm...

[zippo01]

But what will keep me warm on those long lonely nights while I watching inappropriate things on my phone?

Re:Please keep me warm...

[ozmanjusri]

Friction.

Re:Nah.

[Neil Boekend]

Nope, because it doesn't increase the range of the antenna. The same limits to transmitted power apply, no matter what technology you use to transmit it.
Besides, in heavily populated area's the number of antennas has nothing to do with transmit power, but with maximum throughput.

I dont blame power amplifiers

[aXis100]

Pretty sure most of the power used is not in the radio - before "smartphones" we had phones with similar battery capacities achieving much longer standby times AND talktimes. Even if you turn off a smartphone's Mobile data and stick to Wifi (with only 30mW transmit required), battery life still isn't great.

I think it's got a lot lot more to do with:
- Big, bright displays
- Multicore, gigahertz CPU's regularly kept busy with background apps
- Far more sensors embedded in the unit to power - GPS, accelerometers, etc.

Re:I dont blame power amplifiers

[icebrain]

I think it's got a lot lot more to do with:
- Big, bright displays
- Multicore, gigahertz CPU's regularly kept busy with background apps
- Far more sensors embedded in the unit to power - GPS, accelerometers, etc.

Plus, the whole obsession with "the phone must be THIN!!!1!"
If the manufacturers quit worrying about trying to fit the phone into the form factor of an index card, there would be enough thickness for a reasonable battery.

Re:I dont blame power amplifiers

[Spacelord]

It really is mostly the displays. On Android phones you can see what is using the battery, and it's almost always 60-70% the display.

As for those multicore CPUs, modern smartphone operating systems are remarkably good at keeping them clocked down when they're not needed. As a matter of fact, if I leave my Galaxy Nexus unattended (i.e. don't use the display), there hardly is any battery drain. I wouldn't be surprised if it would last a whole week that way.

Re:Android battery stats

[Anne Thwacks]

You must be new on planet news: could save up to 50% means "will probably save less than 5%, but we need a grant".

Smartphones that Use Half the power

[TheInternetGuy]

Breakthrough Promises Smartphones that Use Half the Power

Seems inefficient, wouldn't it be better if they used all the power?

Class C

[GrahamCox]

Class C RF power amplifiers can be ~90% efficient, because they drive a tuned load. That's been known for most of the 20th century. Is the problem that these need to be wideband amps? Perhaps there is a clever way to reconcile those needs, though I'm not seeing it.

Re:Class C

[Gordonjcp]

No, the problem is that they need to be linear. You can use class C for FM (and therefore GMSK) because you're running at full carrier power continuously. For 3G, you need a linear amp because QAM has potentially got a variable carrier level. There are tricks you can do to get round this (envelope restoration) which could be what TFA is on about, but it's slashdotted.

Re:Class C

[smpoole7]

> Class C RF power amplifiers can be ~90% efficient, because they drive a tuned load. That's been known for most of the 20th century. Is the problem that these need to be wideband amps?

You're on the right track, but the answer is a bit complicated. (The article, by the way, sounds like a PR piece for someone expecting to patent a technology that, by the same arguments we use against software patents, probably shouldn't be patentable, because it's an obvious rearrangement of existing technology. I shall elucidate.)

1. Yes, it's difficult to run wideband amps in class C. Class C works best with a single frequency at a constant level.

(To illustrate: my wideband HD transmitter, for example, must be re-biased to class AB. I can switch it to "pure" class-C FM mode and it puts out 2-3 times the power as when it's in HD mode.)

2. As a general rule: designing an efficient amplifier becomes more difficult the higher the frequency. Wireless phones run at high frequencies.

(To illustrate: class D switching amps have made it possible for your teenage son to have 1,000 watts of audio in his Nissan Sentra. But you must use a switching frequency that's much higher than the signal -- easy to do with audio, not so easy with even just an 800-900 MHz wireless signal.)

3. Read the fine print and look beyond the smoke.

We just went with Modulation Dependent Carrier Level (MDCL) on our 50,000 watt AM, and it has indeed cut our power bill substantially, which is strikingly analogous to what these people are proposing. But this is highly dependent on modulation (i.e., what we're "playing" at any given moment, whether music or voice) and other factors.

In this case, if they're obtaining the higher efficiency by "smoothly" switching between standby and active modes, one wonders how efficient it will be during rush hour, when everyone is on the phone, calling their significant other to have dinner ready when they get home. :)

A Gadget?

[jamesl]

... the power amplifier, a gadget that turns electricity into radio signals.

Any article that calls an important piece of technology a "gadget" is neither serious nor credible.

Envelope tracking

[Iconoc]

What this article never really manages to describe is Envelope Tracking (ET). This has been in development for several years. Look at the diagram in http://www.nujira.com/technology-pa-746.php for a better description of the concept. This article describes the application of ET in the handset.

Re:Nah.

[realityimpaired]

My phone can go about 5 days if all I do is idle. That's with Bluetooth and 3G data services/sync turned on, but wifi radio turned off. If I nix Bluetooth and/or data services, I can increase that.

I'm all for reducing power consumption, but if it's not going to reduce the power consumption when the device is actually being used to transmit, then how is it going to increase battery life noticeably when most smartphone users plug it in every day anyway? Besides which, the screen is what eats up the lion's share of my battery... simply decreasing the brightness of the screen makes a huge difference in the life of the battery.