Some Basic questions related to transmission line

[sweetchoto]

Hi All,

I need some basic reasoning for the following questions related to the transmission line theroy. Hope so i will get some good answers or documents or links which will clear it up.

when a transmission line is left open at one end, the fringe fields are modeled with a parallel capactitor from the end of the line to ground. So the questions is:

•In a design of a matching network, a shunt open stub has a length equal to 70 degrees and Z0=85ohm. If the fringe capacitance is 0.5pF how should the paramters of the line be implemented?

•The physical length of the line is going to be very long. What can you do if you want to perform the matching with the same design?

Hope to get some interesting answers.

/Sc

 

[tony_lth]

The open end effect can make the line a little shorter.
That line is TEM mode, so the impedance is independed on the length of the line if you match each end to 50R.