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Where do they get these guys? First he says that it doesn't use any spectrum...then he says that anything below 2 GHz will interfere with existing Nav and Comm systems. Gotta be one or the other. Can't be both.

Yes, it can be both

UWB works by sending single-cycle pulses. The information is carried by when the pulse is transmitted with respect to a reference.

Since there is no carrier, it doesn't affect a specific part of the spectrum. However, since there is no carrier, it affects all parts of the spectrum by adding to the noise floor. That is what the big problem with this technology is and why the FCC is looking so closely at it. The UWB Consortium has more information.

Personally I don't see a problem with raising the noise floor for this technology because, as I understand it, it raises the floor uniformly and, if I understand this correctly, the actual number of devices transmitting doesn't play into this.

I've been interested in this for a while. Time Domain (warning, flash-heavy site) is a company which has been playing with this for a long long time. I was rather skeptical of this when I first heard of it but my opinions on it are changing. Hell even EDN had an article on it.

The only thing I don't quite grok is how they can get two devices to have such rock-solid stable time references (we're talking sub-picosecond jitter) without secondary clock transmitters and keep them that way. If anyone out there can help shed some light on it I'd love to hear from you.

The author is obviously a dill-hole!

Check him out:
SMILE!

We haven't found ways around physical laws. We have found physical laws that we hadn't previously known of. How things were made of molecules, how molecules were made of atoms, how atoms were made of particles, how particles were made of ...well, quarks, probabilities, wave functions...

"At hyper frequencies (1.2ghz and higher) I could see some kind of a spread spectrum system working, but anything lower is plain impossible."

There's nothing magical about high frequencies (well, except maybe popping corn). Spread spectrum can be done at any frequency, but does not allow any faster data transfer than if you had a similar transmitter locked on an unchanging frequency.

"You have a specific capacity at X frequency, Example 108 MHZ - you have a maximum of 108Mbps if you were able to encode on every cycle of the carrier (impossible without generating nasty things)"

Well, maybe you have to define "nasty things", such as "bandwidth". You'll have to encode your signal somehow. A phone line has a bandwidth of about 3KHz, but we can send more than 3Kbps. Part of that is due to sending several frequencies, but most of it is due to using one signal change to indicate more than one bit signal. For example, using two tones to indicate four bits, loudness of the two tones to indicate more bits... You can see a summary of the technology, although real modems are more complex.

The hard part is knowing at what point engineering ends and fiction begins. Sometimes it's easier when someone points out the fiction to you, such as when a picture of a board for sale shows a chip is longer than the socket it is plugged into.

A recent article in EDN Access says that a new technology will allow 90bps/Hz of bandwidth. First generation CDMA uses 1.5 Mhz of bandwidth which should provide 135Mbs!

Second generation CDMA uses 5 Mhz of bandwidth, which could theoretically provide 450Mbs of bandwidth using the new technology.

I share your frustration. FRAM is actually being researched and produced by big companies such as SAMSUNG in densities as high as 4Mb. You are not correct, though, to say that FRAM is denser than flash. Remember that flash can store two bits in a very small memory cell. So far, flash has also proved more scaleable than FRAM, which is why you see flash densities today orders of magnitude better than FRAM even though FRAM is an older technology. A good reference for reading about non-volatile memory technologies can be found at EDN Access

Anyway, I went to google for some links.

Here is a fairly general overview of EMI in computers. It talks about various strategies for dealing with it.

Here is an article mostly about SDRAM, but which says the following: "Spread Spectrum Clocking (SSC) is a frequency modulation technique for EMI reduction. In the latest motherboards, the master clock generator chip does not maintain a constant frequency." Anyone know if that is true? I didn't know that...

Finally, an article showing Intel is concerned about the problems of EMI in modern computers.

All in all, interesting stuff (I love absurb overclocking articles!) but I would like to have found some evidence that shielding memory like they did has any real benefit.

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