Device for producing microwave signals

摘要

The present invention describes a device for generating microwave signals, particularly for use in a distance and speed sensor in a motor vehicle. To this end, two laser sources are operated, whose emitted radiations are distinguished from each other by a set difference in wavelength. The two lasers are arranged in such a way that the emitted laser beams overlap spatially. A photodiode is disposed in this region in which the two laser beams interfere. From the superimposition product of the two laser beams, this photodiode generates an electrical output signal that has the differential frequency of the two superimposed laser beams. In this context, the frequency difference of the two lasers is selected so that the frequency of the generated microwave radiation lies in the range of the radar beam to be generated.