RF circuits help

Discussion in 'The Projects Forum' started by schall92, Nov 29, 2012.

  1. schall92

    Thread Starter New Member

    Nov 29, 2012
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    Hi I'm doing some research on radio frequency circuits in hopes of playing around with them a little. Whenever, I see a basic RF circuit, especially AM circuits, there are always transistors. Are those for amplification purposes only or is there some other use for them in the network? Could I substitute an amplifier IC for the transistor and its accompanying components? (resistors and capacitors) Thanks.
     
  2. tshuck

    Well-Known Member

    Oct 18, 2012
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    depending on the arrangement they are also used for the modulation...
     
  3. schall92

    Thread Starter New Member

    Nov 29, 2012
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    Do you know how they are used for that?
     
  4. tshuck

    Well-Known Member

    Oct 18, 2012
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  5. vk6zgo

    Active Member

    Jul 21, 2012
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    I suggest you have a look through the ARRL Handbook or something similar.
    Transistors (both BJTs & FETs) are widely used in RF circuits,as are ICs.

    The ICs used at RF are often specially designed for such frequencies,& using a standard Op Amp or similar,may yield disappointing results.

    Some RF beginners on this forum seem to get hung up on low frequency design & construction methods which don't work well at higher frequencies.
    Also,many "example" circuits which appear on the 'Net are merely to illustrate concepts,& do not lend themselves to practical use.
     
  6. Papabravo

    Expert

    Feb 24, 2006
    10,145
    1,791
    Even in a receiver there are transistors that are used as oscillators to provide various useful functions. Learning to read datasheets is the key to understanding what you can and cannot do with a component. A serious study of RF engineering includes the acquisition of a deep understanding of passive AC circuits involving inductors and capacitors. A little algebra of complex numbers never hurts either. You can hold of on the calculus and differential equations for a while, but not forever.
     
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