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    Insertion Loss & Return Loss [hlp]

    Hello everyone;
    Suppose a two-port network with scattering parameters. Please express Return Loss & Insertion Loss by scattering parameters.

    •   Alt21st February 2006, 08:34

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    Re: Insertion Loss & Return Loss [hlp]

    Hi,

    Insertion loss is S21 [dB]
    Return Loss(es) are -S11 [dB] and -S22 [dB] (minus sign, they are expressed as positive values)

    flyhigh


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    •   Alt21st February 2006, 10:27

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    Re: Insertion Loss & Return Loss [hlp]

    Just a small correction.
    Insertion loss is -S21 [dB]


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    •   Alt21st February 2006, 12:19

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    Re: Insertion Loss & Return Loss [hlp]

    Hi,

    yes, of course, S21 comes with minus sign as well.


    flyhigh



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    Re: Insertion Loss & Return Loss [hlp]

    S21 is the Gain of the two port device! Pout/Pin
    If it is a lossy or passsive device the gain will be zero or negative (Insertion Loss).
    If it is an active device it should have some gain, making it a Positive S21

    S11 is the Input ReturnLoss Looking in to Port 1 Pin(forward)/ Pin(reflected Back)

    S22 is the Output Returnloss Looking in to Port 2 P(forward)/ P(reflected Back)

    When S11 & S22 are Very Negative (dB) That means that none of the power going
    in to the port get reflected out!


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    Re: Insertion Loss & Return Loss [hlp]

    S11 is the Input Return Loss and S22 is the Output Return Loss ONLY if S12=0 !!!



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