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 clarification on LNA design 

Last post Sun, Sep 4 2011 12:14 AM by RFQuery. 3 replies.
Started by RFDESIGN 2008 20 Aug 2011 01:59 AM. Topic has 3 replies and 3920 views
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  • Sat, Aug 20 2011 1:59 AM

    clarification on LNA design Reply

     Hi

       Any one help me that i am doing Complemetary current reuse LNA in MICS band in Cadence spectra...i selected one IEEE paper regarding my project..In that they didnot mention any device specification (i.e., value of inductor,capacitor,resistor,width of transistor) also i don't know how to desidn these device values also...My operating freq is 401-406MHz

               In that circuit, one inductor s connected to gate of nmos transistor and one capacitor is connected between gate and source of transistor.. and rf input s given to one end of  the inductor  and vbiase is given to the other end of inductor.. if we give vbiase as dc source means output also dc voltage, sine wave output s not coming..  I am not getting output for LNA..

         Please any give idea for LNA design...

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    • Post Points: 5
  • Sat, Aug 20 2011 2:06 AM

    clarification on LNA design Reply

     

     Hi

       Any one help me that i am doing Complemetary current reuse LNA in MICS band in Cadence spectra...i selected one IEEE paper regarding my project..In that they didnot mention any device specification (i.e., value of inductor,capacitor,resistor,width of transistor) also i don't know how to desidn these device values also...My operating freq is 401-406MHz

               In that circuit, one inductor s connected to gate of nmos transistor and one capacitor is connected between gate and source of transistor.. and rf input s given to one end of  the inductor  and vbiase is given to the other end of inductor.. if we give vbiase as dc source means output also dc voltage, sine wave output s not coming..  I am not getting output for LNA..

         Please any give idea for LNA design...

    i send the link where i select the paper

    http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=05716555

    • Post Points: 20
  • Sun, Sep 4 2011 12:12 AM

    • RFQuery
    • Top 75 Contributor
    • Joined on Wed, Jul 20 2011
    • Posts 89
    • Points 1,270
    Re: clarification on LNA design Reply

     Sizing of Devices and passive elements' value selection you have to do taking Matching and gain and frequency of operation into consideration. It ia a TWO nductor source degenerated CS amplifiers with different types of MOSes. So the selction of values and device size requires litle bit more effort.

    For Biasing you have to use a reasonable large value of Resistor in series with the DC BIAS sources so that the RC (input ACcoupling Capacitor) high pass filter can only work at the working frequency to decouple the DC. 

    Thanks-

    • Post Points: 5
  • Sun, Sep 4 2011 12:14 AM

    • RFQuery
    • Top 75 Contributor
    • Joined on Wed, Jul 20 2011
    • Posts 89
    • Points 1,270
    Re: clarification on LNA design Reply

     Also you may go through T.H. Lee RFIC book to understand how an inductror degenerated CS amplifier works as a good MAtching LNA

    • Post Points: 5
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Started by RFDESIGN 2008 at 20 Aug 2011 01:59 AM. Topic has 3 replies.