On the AM Window, I posted mention of a patent I found last week:
A new one, US#7,355,470 just issued to 3 guys at ParkerVision Inc.
Heres a link to it:
http://tinyurl.com/6ktlyj
This patent is ~171 pages long, over half of it being single diagrams and
schematics, one per page. The rest of it is mostly mathematical derivations of
various modulations created by techniques such as Chireix outphasing. I cannot
figure out what is unique about it, what did their claims cover? I think it was
such a massive application that the Patent Office was swamped, and just awarded
another number. Obviously, someone thought this was original work.
To me it appears as a poorly organizated regurgitation of everything you wanted
to know about high efficiency outphasing transmitter, EER, LINC transmitter
topologies. What IS useful is that this patent pretty much lists as references
every patent back 50+ years on high efficiency power amplifiers, using these
modulation techniques. Its a nice list that by itself gives us a great place to
search for the real thang. Finally, it has a huge 'other publications list'
which also covers almost everything that has been published in this arena. More
bizarre, I found my own name in this list, with a link to an online discussion
on the RCA Ampliphase design, "Amplifuzz", on the Amps@contesting.com in 2005.
So maybe these guys read AMPS? Or just did a search on Ampliphase and found
this.
The Barron's article on these guys (Jeff Parker) says a lot.
http://online.barrons.com/article/SB119647334993210312.html?mod=googlenews_barrons
Interesting way to make a buck, though, by short selling their stock at the
same time running a website dispelling the myths of Parkervisions technology.
PV basically tried to patent Chiriex Outphasing modulation. It was an elegant
invention in its time, and Ampliphase was the name that RCA trademarked in
their BC transmitter line in the 1960s. Hard to understand ParkerVisions stuff.
They attempted to sell 802.11.g WIFI boxes to consumers, and left that market
few years ago. Their website lists technology, in vague terms, and even has a
page of measurements of efficiency versus power level for various forms of
digital modulation, made with real Agilent test equipment. Yet there are no
products for sale (just technology?). If you listen to their latest investor
conference call (on the PV Notes website) you hear how they cannot tell their
investors who their potential new customers are, but that turnaround is just
around the corner.
Steve Cripps' review of their vector modulation patent sums it up, tecnically:
http://www.pvnotes.com/d2p-patent-analysis
73
K5PRO
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