+ Post New Thread
Results 1 to 8 of 8
  1. #1
    Advanced Member level 3
    Points: 3,991, Level: 14

    Join Date
    Feb 2016
    Posts
    783
    Helped
    1 / 1
    Points
    3,991
    Level
    14

    Controllable gain power amplifier

    What is ng ?

    What are the purposes of Ctrl0, Ctrl1, Ctrl2 and Ctrl3 ?

    Click image for larger version. 

Name:	WG1pY8F.png 
Views:	2 
Size:	131.2 KB 
ID:	157929

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 5
    Points: 31,248, Level: 43
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,590
    Helped
    1384 / 1384
    Points
    31,248
    Level
    43

    Re: Controllable gain power amplifier

    M5e,M4e,M3e,M2c,M1C are Cascode+Switch pair MOS Transistors.When Ctrlx Input is tied to positive voltage, each becomes active so the Gain is controlled.
    Pay attention to Ng fields , they are not identical amplifiers.



    •   AltAdvertisement

        
       

  3. #3
    Advanced Member level 3
    Points: 3,991, Level: 14

    Join Date
    Feb 2016
    Posts
    783
    Helped
    1 / 1
    Points
    3,991
    Level
    14

    Re: Controllable gain power amplifier

    So, I could just connect Ctrl0, Ctrl1, Ctrl2 and Ctrl3 to Vdd ?

    What about L_stage1 and Bias2 ?

    Should I just connect these two to Vdd ?



    •   AltAdvertisement

        
       

  4. #4
    Advanced Member level 3
    Points: 3,991, Level: 14

    Join Date
    Feb 2016
    Posts
    783
    Helped
    1 / 1
    Points
    3,991
    Level
    14

    Re: Controllable gain power amplifier

    Wait, this variable gain amplifier does not fall into any class of RF Power Amplifier ?



  5. #5
    Super Moderator
    Points: 265,369, Level: 100
    Awards:
    1st Helpful Member

    Join Date
    Jan 2008
    Location
    Bochum, Germany
    Posts
    46,364
    Helped
    14112 / 14112
    Points
    265,369
    Level
    100

    Re: Controllable gain power amplifier

    What about L_stage1 and Bias2 ?

    Should I just connect these two to Vdd ?
    L_stage1 hardly. Bias2 may be, depending on the intended quiescent current.

    this variable gain amplifier does not fall into any class of RF Power Amplifier ?
    What's against class A?



  6. #6
    Advanced Member level 5
    Points: 31,248, Level: 43
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,590
    Helped
    1384 / 1384
    Points
    31,248
    Level
    43

    Re: Controllable gain power amplifier

    L_Stage1 is probably tied to an external bias circuit or supply line through a lambda/4 line or RFC or similar one.
    Bias2 is independent bias of M6


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  7. #7
    Advanced Member level 3
    Points: 3,991, Level: 14

    Join Date
    Feb 2016
    Posts
    783
    Helped
    1 / 1
    Points
    3,991
    Level
    14

    Re: Controllable gain power amplifier

    @BigBoss What do you exactly mean by RFC ?



  8. #8
    Advanced Member level 5
    Points: 31,248, Level: 43
    BigBoss's Avatar
    Join Date
    Nov 2001
    Location
    Turkey
    Posts
    4,590
    Helped
    1384 / 1384
    Points
    31,248
    Level
    43

    Re: Controllable gain power amplifier

    Quote Originally Posted by promach View Post
    @BigBoss What do you exactly mean by RFC ?
    Radio Frequency Choke Coil..



--[[ ]]--