What are the electrical lengths of the long transmission lines on my impedance standard substrate?
If TRL calibration is used the delay of the long lines will need to be supplied to WinCal or directly to the VNA. These delays are readily determined from the drawing supplied with the ISS. Simply measure the line using a scale provided on the ISS for this purpose. Remember to allow for the probe contact overlap – about 50 um on each end. Each 130 um (0.130 mm) of length corresponds to approximately 1 ps, so delay may be calculated from T (ps) = Length (mm)/0.13 (best fit).
