Tayloe Detector patents and prior arts?
Boy was I naive! I found out about how bad intellectaul property issues can be. First I asked Dan Tayloe if I could pay Motorola to use his patent and he said Motorola had sold it. Then I found some French company that buys up intellectual property had bought it apparently. They never responded to my request to pay a license fee or something.
Then I saw that there is possible prior art: The D. H. van Graas Detector, the MerryGo or Merigo Japan patented circuit and the Rodney Green Australia patented dirodyne circuit. I see Gerald Youngblood and others have subsequently patented their own version of it also.
Then I saw a huge court battle between Qualcomm and Parkervision and it seemed to be over the same design but I never saw where either of them had bought rights from Dan Tayloe/Motorola or from any other of the prior art inventors.
Does anyone know if it has been decided that this design is open source now? I see so many SDR radio designs using it.
George
Today, thanks God that you can still use the Colpitts oscillator without paying any fees.
BTW. It is something Tayloe-like Detector from V.T.Polyakov's article "Synchronous AM receiver" from the soviet "Radio" magazine №8, 1984
К176КТ1=CD4016
К176ТМ2=CD4013
К176ЛЕ5=CD4001
Ledum,
Ah! I see now the date with that article you attached. That is great! The attachment didn't pop up on my webpage until after the message I wrote below.
Do you know where I can find the article translated to English with diagrams intact?
Does anyone know where I can find a copy of this article with diagrams intact?:
van Graas, ?The Fourth Method: Generating and Detecting SSB Signals?, QEX Sep 1990
It appears the judge in the court battle between Qualcomm and Parkervision was more interested in helping a corporation get this technology than in helping all the little people with prior art. He said he felt it was ok to ignore the Tayloe patent application because it was filed only 5 days before.
If I can find some article of prior art that shows the circuit then I can justify to myself at least going ahead and selling it if I make one that works well.
I agree with what Gerald Youngblood wrote in one article, that the signal holding capacitors are a key feature along with the quad analog switch or quad transistor switches in a sequential configuration rather than in a ring, so if I can find prior art of that then I'm set. I think a patent for a mixer with 2 FET rings driving 2 capacitors is equivalent to a 1:4 analog switch driving 2 capacitors but it is harder to make judges, juries and lawyers understand that.
The diagram in this article shows the effect on BW of the signal hold capacitors but it doesn't clearly show the sequential switching:
http://www.engr.sjsu.edu/~rmorelos/e...ers.pdf
I'm hoping the van Graas circuit will show more clearly but I haven't found the article yet.
73
George
AF5IE
Sorry. There are no known to me translations of this article. But you can use google translation http://translate.google.com/translat...Fradio64.shtml . He did not patent his detector ;). Signal is divided in two parts - The first one (inphase) is used to demodulate a useful signal, and the second one (quadrature) is used to phase lock LO to station signal for synchronous AM demodulation by cost of 3dB increasing in loss at the detector due to divider.
I must confess that I didn't come across the term "Tayloe detector" before reading your post. Homodyne or zero IF receivers are known to me since my university years and as I presume prior art since at least 40 years. I must confess that I'm not too motivated to research in detail what a 1998 filed patent might add to the basic homodyne receiver concept, I also don't see a detailed discussion of prior art in the document.
I know a lot of patents that are objectively void from the beginning.
Chris Trask sent me the van Graas article from 1990 QEX. It is all perfectly detailed. It is crazy that the Qualcomm vs Parkervision judge was saying they could ignore this prior art. I hope I attached the file correctly to this message.
I found the Mother lode of prior art but I can't figure out yet why the court ignored it.
http://www.parkervision.com/public_r...e_PDFs/296.pdf
Ignoring the patent battle the document is referring, this is one of the most explicit explanation of an electronic circuit that I ever seen.
Of course, the main reason is because the quoted expert is Dr. B. Razavi.
I wish to see more documents like this.
But unfortunately it doesn't seem to help at all.
Which reminds me to the German saying "'before the court and on the high sea one is in God's hands".
I made one of these 'polyphase' SSB generators many years ago. I think I still have the audio phase shift matrix somewhere. I've been trying to remember when I built it and I'm guessing it must have been in the mid 1970s. It was certainly before 1978 because I moved house then and had it in use before relocating. I remember using car 'touch-up' paint and a brush to draw the PCB tracks before etching as none of the modern convenient methods was available then. So that pre-dated even the Polyakov design by a few years!
I'll have to dig into my old junk boxes and if I can find it, see if there are dates on the capacitors.
Brian.
Maybe since both corporations wanted at least some of the court records sealed, maybe there is some new aspect to the circuit that both corporations are claiming. Maybe they both use a new topology of connecting between the switches and the capacitors or maybe they both use special opamps, like zero drift or something that prior art was not showing.
Hi George. I have never done anything about the patent I filed. I also think that it is OK for an individual to use patented technology themselves. Cheers from Rod VK6KRG