A method for testing a distance sensor includes: receiving an electromagnetic free-space wave as a receive signal; generating a simulated electromagnetic reflection signal therefrom; shifting a reflection frequency of the reflection signal by a Doppler frequency smaller than a signal bandwidth of the receive signal; converting the receive signal into a first work signal having a first work frequency smaller than a receive frequency of the receive signal; converting the first work signal into a second work signal having a second work frequency, wherein the difference between the first and second work frequencies is at least as large as the signal bandwidth plus the Doppler frequency; converting the second work signal into a third work signal having a third work frequency that corresponds to the first work frequency shifted by the Doppler frequency; increasing the third work signal by the conversion frequency; and radiating the third work signal.