Analog multiplier ic

Discussion in 'General Electronics Chat' started by almoatazbellah, Dec 9, 2010.

  1. almoatazbellah

    Thread Starter New Member

    Nov 24, 2010
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    hi all,

    iam looking for an analog multiplier ic that can multiply two inputs one with a frequency 1KHZ and the other input with frequency 60MHZ , i found MPY634 multiplier but i am not sure if it is the right one cuz it have a 10MHZ bandwidth. some help would be appreciated.
     
  2. Ron H

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    Apr 14, 2005
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    You need at least 80-100MHz bandwidth. Why do you want to multiply 1MHz and 60MHz? There might be other solutions.
     
  3. tyblu

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    Nov 29, 2010
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  4. Ron H

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    AD539 minimum BW is 30MHz, which is too low for the OP's application. Analog Devices has AD834 and AD835, which have 500MHz and 250MHz bandwidths respectively. Either would probably work, but, as I said, there might be a simpler solution if we knew what our OP is trying to do.
     
  5. tyblu

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    Nov 29, 2010
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    I thought for sure it said 60MHz. Oh well.
     
  6. Ron H

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    It says 60MHz typical. I think even that is too low for his app. When you multiply 60MHz and 1MHz, you get sidebands at 59MHz and 61MHz. In some applications, constant group delay and flat amplitude response over the output frequency spectrum is probably important. You don't get constant group delay and flat amplitude response at the band edge of a filter, which is basically what the roll-off is. That's why I said he probably needs at least 80-100MHz BW.
     
  7. almoatazbellah

    Thread Starter New Member

    Nov 24, 2010
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    thanx for replying guys, as i said before i want to multiple 1KHZ with 60MHZ,
    and that is to modulate a train of pulses 1KHZ frequence with a carrier 60MHZ, so i can transmit it through antenna it's a prototype project.

    the result that i expecting it from this multiplication is shown in the picture below
    [​IMG]

    is it suitable to use AD539 since it have 60 MHZ bandwidth or there is a simpler solution ?
     
  8. beenthere

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  9. almoatazbellah

    Thread Starter New Member

    Nov 24, 2010
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    ya i got it wrong forgot about this picture
     
  10. Ron H

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    Technically it is still modulation, but I agree that an RF switch is a much better solution than a linear multiplier.
     
  11. almoatazbellah

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    Nov 24, 2010
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    i need a multiplier in both transmitter and receiver , thats why iam looking for the proper one right now , i guess ill try AD539 it has 60 MHZ bandwidth.
     
  12. Ron H

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    Why do you need these two multipliers? As mentioned, on/off modulation can be done with a switch (RF). In the receiver, detection (demodulation) can be done with a diode detector. An analog multiplier is massive overkill unless you are trying to do something much more sophisticated than I am imagining.
     
  13. almoatazbellah

    Thread Starter New Member

    Nov 24, 2010
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    you right , but i have no knowledge about RF switch , ill try google thanx man.
     
  14. Ron H

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    Go to the link in post #8. Analog devices probably also has an application note covering RF switches.
     
  15. almoatazbellah

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    Nov 24, 2010
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    thanx alot
     
  16. steinar96

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    Apr 18, 2009
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    I recommend switching over multiplying. To demodulate the multiplied signal in the reciever the reciever's multiplier needs to be synchronised in phase and frequency with the multiplier in the sender. Which is a problem since they are independent from each other unless you go trough the trouble of setting upp a PLL and methods to extract the phase of the incoming signal. You may ofcourse know this already but your current method requires coherent detection. Noncoherent will save you alot of time and money
     
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