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Relative Phase Shift Measuring

Boris LVIN
Prodigy 50 points

Does TI (or may be some other company) have something better

than 10 years old Analog Device AD8302 chip to measure

relative phase shift? AD8302 does not determine the sign of the

phase shift and has poor accuracy in the case of the

shift close to the zero.

Thanx

  • 0
    TI__Intellectual 1650 points

    Hey Boris,

    Just letting you know I have sent some emails around to people in the factory to see if we have a device like this.

    The group that controls this particular E2E forum does not have a part like this, but we're searching. 

    I hope to have an answer to you soon.

     

    Chris

  • 0 in reply to Chris Pearson
    Prodigy 50 points

    Hey, Chris, thank you for your answer.

    We are going discrete for our network analyzer for now.

    We would like it to be full-range (0..360 degrees) and without the (the most important) spots (like 0) where it looses the accuracy.

    Boris

  • 0 in reply to Boris LVIN
    TI__Intellectual 1650 points

    Boris,

    Just following up. My contacts have replied that they do not know of a similar part at TI.

    Are there any part types we can help you with on the discrete components?

    Thanks

    Chris

  • 0 in reply to Chris Pearson
    Prodigy 50 points

    Thank you, Chris.

    I have already ordered some TI samples and we'll definitively use them in the future iterations of our prototype.

    But it is possible that this is the case when not only TI may help us, but also we may help TI:-).

    We are building a network analyzer and would like to use the 10-year-old Analog Devices AD8302 chip to 
    measure relative phase shift, but can not, as it does not determine the sign of the phase shift and has 
    poor accuracy in the case of the shift close to the zero.

    We talked to several other manufactures and found out that none of them (including TI) has anything
    suitable. It looks like AD8302 after 10 years is still the only game in town, most likely because some
    patents are involved. Analog Devices has few of them covering AD8302. At the same time AD8302 only 
    does a limited amount of work and does it poorly in the most important case, such as when two signals
    are close.

    We ended up constructing a discrete solution which we think is simple and efficient. It 
     - allows the measurement of relative phase shift over the entire 0 to 360 degree range and
     - does not exhibit instability or loss of accuracy.

    It looks like nobody has achieved this before. We have prepared a patent, submitted it to a Patent
    Attorney and expect to file shortly.

    That is why we are investigating if some manufactures (e.g. TI) will be willing to try to build the chip based on it. 
    Technically it should not be a challenge - nothing in it is more complicated compare with what everybody have
    already done many times. 

    Somebody, who is in charge, should see if the market is big enough to build new precise full-range circuit for
    relative phase shift measuring. It may be either upgrade or a competing product to the aging Analog Devices chip.

    We are also looking for suitable applications for our invention. Using it we are constructing network and antenna
    analyzers. We started with specific design goal and now it appears to us that invented circuit has much more
    generic use. E.g., if a logarithmic amplifier is included with the full-range relative phase shift measuring device, as
    in AD8302, we are getting a universal detector that allows simultaneous analysis of both signal gain and phase. 
    In fact the circuit may be used for quadrature demodulation. 

    We aware of the problems with AD8302 use in microwave holography.
    http://www1.oan.es/informes/archivos/IT-OAN-2012-5.pdf

    It is possible, that our invention might be used for phased arrays, which currently used relatively coarse data 
    because of the difficulty of making relative phase shift measureless. 

    We think that our invention will be useful tool whenever relatively narrow band signals need to be analyzed.
    Thank you very much for your attention for us. We'll appreciate if you also manage to pass this kind of message
    to the people in TI, who may be interested to improve very impressive TI line of products.
    Tnanx again,
    Boris
  • 0 in reply to Boris LVIN
    TI__Intellectual 1650 points

    Boris,

    Thanks.  I started a private conversation thread with you to discuss further.  Just so one of your competitors be able to search the information you wrote on this external forum.

    Chris

  • 0 in reply to Chris Pearson
    Prodigy 50 points

    Hi, Chris,

    I got your questions and understand your concerns (I also have them:-).

    I'm answering to them right now to the best of my knowledge by e-mail.

    Do you want me to remove my the message(s) from the forum?

    I'll do it if you tell me how to do it.

    Or, it may be simply if you do it from your side.

    I will not complain:-)

    Talk to you soon.

    Boris

  • 0 in reply to Boris LVIN
    TI__Intellectual 1650 points

    Boris,

    From a TI side I don't think anything has been shared that I'm worried about, but if you feel there is information up there that you do not share let me know and I'll try to figure out how to have it removed.

    Chris

  • 0 in reply to Chris Pearson
    Prodigy 50 points

    Chris,

    everything is fine.

    Thank you.

    Boris