I am using an ENA E5071c vector network analyzer for two port microwave measurements. I am trying a TRL (Thru-Reflect-Line) calibration for the first time using four standards: Thru, Reflect and two Lines. I always perform thru, then reflect, then the lines (low frequency and then higher frequency defined). After I complete the calibration, I have no idea what to look for in terms of the S-parameters to verify the calibration was sufficient. Right now I end on a line, but I do not know what the line should look like on the smith chart (still learning all of this). Please enlighten me!