s parameters for small length wires
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.
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.
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
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.
