I need to plot a graph of the reflection coefficient against the frequency.I ran an AC sweep of in the range of frequencies I need. However I am unsure of how to get the reflection coefficient on the y axis for the circuit I want to stimulate. Will I have to use an additional component ?. Anybody familar with PSPICE please advice?.
You need to find a means to measure input voltage and input current from your circuit. Then you can convert to complex impedance: Zl = V/I
Then gamma = (Zl - Zo) /(Zl + Zo) where Zo is the transmission line impedance.
You may be able to use an AC current source Into the DUT to find impedance