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This is more like "Make" magazine savvy. Decoding the Mode-S transponder data sent on 1090 MHz would be a hell of a lot cooler, and would get all aircraft within range, not just the ones talking on a particular freq.

Amateurs.

Antenna design for hand-held devices at these frequencies and power levels is not exactly trivial, and minimizing the effect of the human body (hand) on the antenna characteristics is the subject of much research in the industry.

http://lup.lub.lu.se/luur/download?func=downloadFile&fileOId=1152137

http://www.rfm.com/corp/appdata/antenna.pdf

http://www3.interscience.wiley.com/journal/120848913/articletext?DOI=10.1002%2Fmop.23715

http://ieeexplore.ieee.org/iel5/11208/36089/01710996.pdf

http://e-citations.ethbib.ethz.ch/view/pub:18638

http://www.waset.org/journals/waset/v49/v49-156.pdf

http://www.amazon.com/Hands-effect-Shahla-Moradi-Shahrbabak/dp/3639175425

http://www.google.com/search?q=effect+of+hand+on+antenna&hl=en&client=safari&rls=en&ei=GbZBTOP-NIP-8Aaw_aUZ&start=10&sa=N

http://rfdesign.com/mag/505RFDF1.pdf

http://www.hindawi.com/journals/ijap/2009/491262.html

http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F4913660%2F4957855%2F04958011.pdf%3Farnumber%3D4958011&authDecision=-203

http://wireless.per.nl/wireless/articles/08_WIC_correlated_coupled_MIMO.pdf

http://www.impinj.com/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=2563>

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.66.2119&rep=rep1&type=pdf

http://202.194.20.8/proc/VTC09Spring/DATA/02-07-08.PDF

AND THAT'S IN JUST THE FIRST THREE PAGES OF MY GOOGLE SEARCH!!!!!!!!!!

Note that this "antennaphile" site called the iPhone 4's antenna design "cool", and said to expect to see other manufacturers adopting similar designs.

Note that the forum thread linked below says that your hand can affect a GHz-band antenna from as far way as 3cm. So where on a phone that is FAR less than 1cm. thick are you going to place that antenna that WON'T have "hand-effects" to some degree? Now, factor in the fact that the FCC MANDATES that the antenna be on the LOWER half of the phone (where your hand naturally grips!), and you can readily see that, as Jobs stated (and demonstrated), EVERY cellphone suffers from the presence of the user. Keep that in mind when you hear people proclaim "NO other phone has these issues." WRONG! EVERY cellphone struggles mightily with this limitation (the presence of the user), during EVERY SINGLE CALL and with EVERY SINGLE USER.

I disagree, but feel free to enlighten me.

Ok, I will.

Antenna design for hand-held devices at these frequencies and power levels is not exactly trivial, and minimizing the effect of the human body (hand) on the antenna characteristics is the subject of much research in the industry.

http://lup.lub.lu.se/luur/download?func=downloadFile&fileOId=1152137

http://www.rfm.com/corp/appdata/antenna.pdf

http://www3.interscience.wiley.com/journal/120848913/articletext?DOI=10.1002%2Fmop.23715

http://ieeexplore.ieee.org/iel5/11208/36089/01710996.pdf

http://e-citations.ethbib.ethz.ch/view/pub:18638

http://www.waset.org/journals/waset/v49/v49-156.pdf

http://www.amazon.com/Hands-effect-Shahla-Moradi-Shahrbabak/dp/3639175425

http://www.google.com/search?q=effect+of+hand+on+antenna&hl=en&client=safari&rls=en&ei=GbZBTOP-NIP-8Aaw_aUZ&start=10&sa=N

http://rfdesign.com/mag/505RFDF1.pdf

http://www.hindawi.com/journals/ijap/2009/491262.html

http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F4913660%2F4957855%2F04958011.pdf%3Farnumber%3D4958011&authDecision=-203

http://wireless.per.nl/wireless/articles/08_WIC_correlated_coupled_MIMO.pdf

http://www.impinj.com/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=2563>

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.66.2119&rep=rep1&type=pdf

http://202.194.20.8/proc/VTC09Spring/DATA/02-07-08.PDF

AND THAT'S IN JUST THE FIRST THREE PAGES OF MY GOOGLE SEARCH!!!!!!!!!!

Note that this "antennaphile" site called the iPhone 4's antenna design "cool", and said to expect to see other manufacturers adopting similar designs.

Note that the forum thread linked below says that your hand can affect a GHz-band antenna from as far way as 3cm. So where on a phone that is FAR less than 1cm. thick are you going to place that antenna that WON'T have "hand-effects" to some degree? Now, factor in the fact that the FCC MANDATES that the antenna be on the LOWER half of the phone (where your hand naturally grips!), and you can readily see that, as Jobs stated (and demonstrated), EVERY cellphone suffers from the presence of the user. Keep that in mind when you hear people proclaim "NO other phone has these issues." WRONG! EVERY cellphone struggles mightily with this limitation (the presence of the user

Imagine ethernet without a checksum, no CSMA/CD algorithm, and reply frame types that can only be told apart by knowing what the request was!!!

Truly frightening, IMHO. I wish they could break with backward compatibility and start fresh with a clean, all-digital, robust solution. They could learn a lot from the cell phone protocols - CDMA, GSM, etc. They deal with huge numbers of transmitters attempting to talk to a central resource - the exact same problem as ATC has.

Five years ago, you were right. Not anymore.

SiGe is killing GaAs.

Many of the devices communicating in the higher frequences of the microwave range are based on Silicon Germanium. This includes cell phones.

Almost ALL WiFi radios are SiGe [PDF warning]. Some have even moved to RFCMOS.

Most GPS devices are SiGe.

Oh, and TV Tuners, too.

Gallium Arsenide *is* exotic, because it has to be done in specialized fabs, not those that run silicon wafers. That significantly drives up the cost vs. SiGe and RFCMOS.

I don't post here very often, but this time I couldn't handle this. (Maybe I should drink less coffee). There was probably some paper at that uni, talking about an incremental improvement in frequency divider design. Ok, cool ... we may or may not see in in a PLL chip in a few years. But the news release (TFA) and RP's writeup are rubbish. Actually, after a bit of Googling, it's all over the net. Next thing I expect, my PHB will ask me to change my totaly unrelated design to use ILFD. My signature notwithstanding, I'll try to pick out some of the c***p, and put some actual information in. BTW, I design 3G mobile terminal circuitry full time. And yes, I am an arrogant SOB. That doesn't make me wrong.

"...But now, researchers of the University of Rochester have developed a wireless chip that needs ten times less power [GC] than current designs."

So far so good.

The new chip relies on a technology named injection locked frequency divider (ILFD) which dramatically reduces the time needed to check for transmission frequencies which are performed several billion times per second by your current phone.

This statement is wrong 2 times. First of all, the time needed to check for transmission frequencies depends on PLL settling time. Nothing to do with divider technology. Even broader scope, it is a rare occurence in 3G that the phone needs to change RF frequency. It's WCDMA, so all cells from a given operator transmit on the same channel. Secondly, tthe checking for transmission does NOT occur "several billion times per second". The RF carrier frequency is several billion cycles per second (ie several GHz). But the carrier frequency is changed on every 10ms roughly, even when it needs to happen. That's 100 times per second. GSM is different, as it does frequency hopping normally, but that doesn't change the point: nothing to do with divider technology.

The new chip uses five transistors and can perform divisions by 3 instead of only 2 by previous circuits

OK, agreed. Anyway, who gives a f**k. A modern PLL chip has a programmable divider, settable from 3 to several thousand. Yes, 3, because it is different technology.

..., allowing a perfect communication between two phones communicating at 2.0001 and 2.0002 gigahertz respectively.

That's not how mobile phones work. Mobiles establish connection with the cell (base station), then remain frequency locked to it, to compensate for temperature dependant frequency variation of their reference reference crystal oscillators - and Doppler shift, if they are moving. A "perfect" communication hardly ever depends on this. And frequency locking does not happen via changing PLL settings in this case anyway - too coarse steps, so other techniques are used.

Anyway, as other people posted already, the frequency synthesizer is not significant contributor to mobile terminal power consumption. Even old PLL chips only use a few milliamps

The ILFD technology seems to be good for building efficient frequency dividers at higher microwave frequencies. That will probably not affect current mobile phones anyway, because all the current systems work around 1-2GHz. Higher up, it's difficult to achieve coverage. Again, other people already pointed this out.

If you want real news in this area, go to sites like this, or this. Slashdot's editorial quality has degraded in the last few years so much that I am thinking about deleting it from my bookmarks.

... use a high-signal white noise generator.

That's the same as lower power 802.11 cards

Bluetooth chips generally eat less than 40mW, some as little
as 20mW. I wouldn't put WUSB in a cell-phone, or my keyboard.

That's the same as lower power 802.11 cards

Bluetooth chips generally eat less than 40mW, some as little as 20mW. I wouldn't put WUSB in a cell-phone.

The article says 802.15.3a will replace BlueTooth, but after googling around there seems to be substantial differences. The can be summed up like this:

. . . . . .Power. . .Speed. . .Distance
BlueTooth. . 1mW. . .0.4Mb. . 10m..100m
802.15.3a. 200mW. . .100Mb. . .5m...20m

The figures were taken from here and here. The figures aren't directly compatible, as Bluetooth takes into account the "Bluetooth protocol" which evidently is optimised for power efficiency, whereas I expect the in typical use your 802.15.3a will have a VB programmer pumping TCP/IP over it. I guess that is the payback Bluetooth gets for all that complexity.

Still, the differences are measured in orders of magnitude. That does not meet my definition of "the same".

Correct me if im wrong, but doesnt Bluetooth ALWAYS ON, suck a lot of battery on mobiles?

Consider yourself corrected. :-) Bluetooth is designed to be a low power consumption technology. My phone lasts for about 5-7 days without a recharge with Bluetooth on constantly. (Less if I talk a lot, obviously) I think you might be confusing WiFi's power consumption with Bluetooth. They are designed for different purposes. WiFi has much higher power requirements and does suck batteries down much more quickly.