amplitude modulation explain

Discussion in 'Homework Help' started by mrmike612, Dec 13, 2012.

  1. mrmike612

    Thread Starter New Member

    Dec 1, 2012
    11
    0
    if anyone knows please explain for me,my modulating signal is square from 0-5v
    the voltage of square with vbias,how does it work to affect the vgs.
    how do i have to choose vbias to make sure it works on reverse-biased
     
  2. WBahn

    Moderator

    Mar 31, 2012
    17,715
    4,788
    Since this is YOUR homework, you need to show what efforts you have made thus far to solve it. We can then look over what you have done right, what you have done wrong, and find a way to get you back on track and moving a bit further down the road.
     
  3. mrmike612

    Thread Starter New Member

    Dec 1, 2012
    11
    0
    hmm....okay....I have some confusions about vbias so I need to make it clear first.I'm not asking for solutions,I'm asking for explaination because i got stuck at my idea.
    My thought was ...square wave fluctuates between 0-5v and to make jfet works as voltage resistor control,we should make Vgs<Vp because the maximum resistance shows at Vgs=vp
    But when we have square and vbias at the same time.how do i identify the voltage Vgs.Thats what I m' confused
     
  4. mrmike612

    Thread Starter New Member

    Dec 1, 2012
    11
    0
    My problem is calculate the proper vbias to make the circuit has the smooth modulation
     
  5. crutschow

    Expert

    Mar 14, 2008
    12,981
    3,221
    Since there is so much variation between FETs I expect you will have to experimentally determine the best bias point for that circuit for the particular transistor you have.
     
  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,157
Loading...