and when a transmission line is terminated in an open circuit, the input impedance is Z(OC)in=−jZ0cotβl Observe what happens when we multiply these results together: \[Z...and when a transmission line is terminated in an open circuit, the input impedance is Z(OC)in=−jZ0cotβl Observe what happens when we multiply these results together: Z(SC)in⋅Z(OC)in=Z20 that is, the product of the measurements Z(OC)in and Z(SC)in is simply the square of the characteristic impedance.