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    s parameters for small length wires

    how to get (simulate) s parameters of small length wires (ic output is connected to sma through pictel connection) in ads. i want to know the impact of the wire on the s parameter of the design. is the length of the wire will impact the overall parameters.
    in case of transmission line we can use a lambda/2 line(of same characteristic impedance) and connect to any port without changing it's parameter. just like the transmission line is there any particular length of wire for which the parameters will not be effected by the wire.

    •   Alt22nd December 2016, 11:21

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    Re: s parameters for small length wires

    A wire isn't a complete circuit, you can't determine its s parameters without specifying the return path, e.g. distance to a ground plane.

    Multiple wires implement a mutual coupling and need to be described by a n-dimensional s-parameter matrix.



    •   Alt22nd December 2016, 17:55

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    Re: s parameters for small length wires

    sorry for the improper term, by wire i meant the cable connected between the sma connector and the board. instead of using the rf cable i have used a smaller length cable, i wanted to know whether a small length of that can cause unwanted effect. i am working in the 3-10 GHz range so for this range also the wavelength is also 3cm. my cable is ~1cm



    •   Alt27th December 2016, 12:42

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    Re: s parameters for small length wires

    As a crude method to simulate you can use a stripline element, make Er =1.0, the Thickness &width = the diameter of the wire, L = 1cm , and the substraight
    height will be your closest ground reference distance.

    But at 3-10GHz expect orders of magnitude variation between simulation and implimentation.

    Good luck.



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