Bi Directional Cellular Repeater 900MHz

Discussion in 'The Projects Forum' started by rohitd, May 18, 2012.

  1. rohitd

    Thread Starter New Member

    Jan 29, 2011
    14
    0
    I am trying to build a cellular repeater. I searched on the internet about this and found out that poweramplifiers are used in it. I saw some products for the purpose and need guidance to complete this project.
    I need to understand that what is a bidirectional repeater? why is it necessary. is there a necessity for some sort of connection (or isolation) between the incoming an outgoing circuit?

    I have searched for a few components
    BFG410W
    BGA416
    MAX2235
    BFP650
    MAX2056
    MAX2057( both these 56 and 57 products for all band amplification)

    New part search are welcome.

    Kindly guide me how can I go on with this project. is there any software to simulate this project?

    Thank you.
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,120
    3,046
    It might be helpful to explain why you want to build something that can be purchased, for instance.

    This would be a challenging project for even an advanced DIY, and would require expensive test equipment most folks don't have. You'll spend far more time and money to complete your project than just buying one. You may still have a good reason, but it would help to share that.
     
  3. rohitd

    Thread Starter New Member

    Jan 29, 2011
    14
    0
    its a project for my final year and i am trying to complete it much before for further experimenting and improvement.
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,009
    3,233
    You need bidirectional because you have an incoming signal and an outgoing signal.

    You generally need some isolation since the outgoing signal is a relatively high power amplified signal as compared to the input. If the high powered output signal gets back into the input you can have an oscillator instead of an amplifier.

    Sounds like you need to do more study on bidirectional repeaters. :rolleyes:
     
  5. rohitd

    Thread Starter New Member

    Jan 29, 2011
    14
    0
    Where can I get more literature?
     
  6. crutschow

    Expert

    Mar 14, 2008
    13,009
    3,233
    I'm no expert on that, so the best I can suggest is a Google search for that. You might look for application notes for the components you posted also.
     
  7. rohitd

    Thread Starter New Member

    Jan 29, 2011
    14
    0
    so far i have come up with the amplification part, duplexer, saw filter. etc do you know anything more i need?
     
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