Method for operating a testing device for testing a distance sensor operating with electromagnetic waves, and corresponding testing device

A testing device for testing a distance sensor operating with electromagnetic waves comprising:

• a receiving element for receiving an electromagnetic free-space wave as a receive signal having a receive frequency and a signal bandwidth;
• a radiating element for radiating a simulated electromagnetic reflection signal having a reflection frequency;
• signal electronics configured to generate the reflection signal from the electromagnetic receive signal the reflection signal having a reflection frequency shifted by a Doppler frequency to be simulated with respect to the receive frequency of the receive signal, wherein the Doppler frequency is smaller than the signal bandwidth of the receive signal;
• a first converter configured to convert the receive signal into a first work signal having a first work frequency, wherein the work frequency is smaller, by a conversion frequency, than the receive frequency of the receive signal;
• a second converter configured to convert the first work signal into a second work signal having a second work frequency, wherein the absolute value of the difference between the first work frequency and the second work frequency is at least as large as the signal bandwidth;
• a third converter configured to convert the second work signal into a third work signal having a third work frequency, wherein the third work frequency corresponds to the first work frequency shifted by the Doppler frequency, wherein the third work frequency corresponds to the first work frequency shifted by the Doppler frequency;
• and
• a fourth converter configured to increase the third work signal by the conversion frequency and thus convert the third work signal into the reflection signal and radiate the third work signal.