What impedance does a 1/2-wavelength transmission line present to an RF generator when the line is shorted at the far end?

A 1/2-wavelength transmission line acts as an impedance mirror, meaning it exactly repeats the impedance present at its far end. Therefore, if the far end is shorted (which represents a very low, or near-zero, impedance), the generator at the input end will also see a very low impedance. Conversely, if a 1/2-wavelength line were left open at the far end (infinite/high impedance), the generator would see a high impedance. A common distractor is characteristic impedance, but the characteristic impedance of the line does not override this 1/2-wave mirroring property.