"money" wrote in message
ps.com...
I have a circuit in which there is a series capacitance of value 680
pF. The characteristic impedance of the line is 50 ohms. Can any
suggest how do i plot the capacitance in the smith chart.

If suppoe it was a parallel capacitance, how do i do it?

Try the free Smith Chart demo at: http://fritz.dellsperger.net/.
Probably the best electronic version I have seen.

73,

Frank (VE6CB)