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  1. #1
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    The stability of the power amplifier

    I found that many desigers put a series resistance with the gate terminal of the cascode amplifiers.
    as shown in the attached figure (circled by red circles)

    Click image for larger version. 

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    Is that only for increasing the stability factor?
    or it has other functions.
    -------------------------------------------------------------
    if the stability are already considered.
    we can remove this resistance as shown in the following cascode circuit (circled by red circle).

    Click image for larger version. 

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    Thanks in advance

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  2. #2
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    Re: The stability of the power amplifier

    As I know it is not for stability, more like the protection of the cascode gate from any supply surge.
    "Try SCE to AUX." /John Aaron/


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  3. #3
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    Re: The stability of the power amplifier

    See this paper: http://www.jpier.org/PIERM/pierm82/01.19041105.pdf

    Suppression of harmonics (HD3) and also ESD protection as mentioned.


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  4. #4
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    Re: The stability of the power amplifier

    They are simply biasing resistors as usually used in Cascode amplifiers.


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