Help! Urgent

Discussion in 'The Projects Forum' started by paulboranits, Apr 18, 2012.

  1. paulboranits

    Thread Starter New Member

    Apr 18, 2012
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    0
    Hello there,
    Can anyone provide me with a three stage RF Power Amplifier circuit or any other details regarding the same. The power amplifier needs to work in the unlicensed band of 54 GHz to 60 GHz. An insight on the s-parameter analysis would help as well.
    A schematic diagram would suffice.
    Would be grateful.
    :)
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,429
    3,360
    Please use a more descriptive title.

    Help! Urgent - helps no one.

    Imagine of everyone used the same Help! Urgent title.
     
  3. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    54-60 MHz is not an unlicensed band as you seem to be asserting. It is unallocated whitespace formerly occupied by TV channel 2. You have not an iota of specification for such an amplifier so it is impossible to know what might meet your requirements. BTW what are your requirements and do you have the skills an equipment to build such a thing assuming you had a schematic?
     
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,779
    932
    I believe he said GIGA hertz not megahertz.

    That freq band will be very hard to work with - even for highly experienced engineers who make a living designing RF amps.

    I doubt very much you will find anything on the internet for 'free' which could cover such a high frequency band.
     
  5. hexreader

    Active Member

    Apr 16, 2011
    250
    82
    Disagree, this title helps everyone to ignore the post completely. :)
     
  6. wayneh

    Expert

    Sep 9, 2010
    12,094
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    +1
    Although we're both guilty of looking anyway. :cool:
     
  7. hexreader

    Active Member

    Apr 16, 2011
    250
    82
    Totally agree :) I ALWAYS look at stuff marked "urgent" just to see how silly the post will be.

    I admit it..... I am human, and I am as bad as all other humans :)

    To make it worse, I enjoy not replying.

    "Let he without sin cast the first stone"
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,094
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    Ahhh, the guilty pleasure. :p
     
  9. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,750
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    People ..quite picking on OP.

    As for his problem, there is no one here who actually work o that frequency.

    I mostly work on Mhz.
     
  10. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    The closest ISM band is 61.0 to 61.5 GHz. This band is even tougher than VHF. I'm guessing you do not posses the CAD system, layout tools, and test equipment to tackle such a project. $150,000.00 might be a reasonable starting budget.

    As for s-parameters they are analogous to h-parameters, y-paramaters, and hybrid-pi parameters in terms of characterizing 2-port networks. They are specifically designed to expose the properties of 2-port networks in RF applications and they ARE functions of frequency. An s-parameter test set and a network analyzer will set you back a very large chunk of change at the 60 GHz frequency.

    http://www.testequipmentdepot.com/usedequipment/networkanalyzers.htm

    scroll down to the 8722ESRFRB which tops out at 50 GHz for $70,000.00 USED!!

    Dream on McDuff
     
  11. paulboranits

    Thread Starter New Member

    Apr 18, 2012
    4
    0
    I was a newbie and didn't know what could be a more appropriate title.
    Thank You for the suggestion.:)
     
  12. paulboranits

    Thread Starter New Member

    Apr 18, 2012
    4
    0
    For realizing the hardware I guess we need to simulate the circuit in mind first.
    I am using Agilent's ADS 2009 and also working on Cadence.
    The two stage circuit schematic which I have simulated in ADS till date is attached below. The gain obtained is 23 dB. This is for the analysis of the schematic in Ac.
    But as I go for S-parameter analysis the results don't show.
    Gain S21 goes negative and S11 & S22 show nothing(Smith Chart).
    I want a three stage as I want my gain to be higher than with that met so that I can use an appropriate linearization technique which will surely reduce the gain obtained.
    A gain of 35 dB would suffice.
    Anyone having knowledge of ADS help if you wish to.
     
  13. MrChips

    Moderator

    Oct 2, 2009
    12,429
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    Simple, state exactly what you are looking for, just as in your first sentence of your first post.

    60GHz RF power amplifier wanted
     
  14. paulboranits

    Thread Starter New Member

    Apr 18, 2012
    4
    0
    Ok I got it
     
  15. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    Not sure where 23 dB comes from. It looks like what you have is a narrow band amplifier with a peak gain that falls of significantly at the band edges. You might want to consider another topology for the gain stages that sacrifices gain for bandwidth.

    I'm surprised that you have realizable MOSFETS that work at this frequency. You might want to check the models. The lack of results in S-parameter analysis suggests that you recheck the possibility that the models don't go there.
     
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