Impedance matching between rectifier and antenna?
The impedance magnitude of 42.4 + j22.5 is 48.0 ohms and I expect that someone in the marketing department for that antenna felt it wouldn't hurt rounding that figure up to 50 ohms.

I would assume the correct impedance is the complex value stated providing: -


The manufacturer is reputable
The dealer is reputable
The data sheet contains very few anomalies like the 50 ohm one


If not a reputable manufacturer/dealer then I wouldn't be keen to trust the data sheet. If the data sheet is of poor quality (in terms of errors/anomalies) then I wouldn't trust the product period.