Patent ID: 6859744

Claim:
A method for carrying out frequency synthesis in a distance measuring device based on a principle of evaluating a change over time in a phase parameter of electromagnetic radiation (S) emitted by a radiation source and remitted by an object at which it is aimed, comprising: generating a high-frequency modulation frequency (M,M*) for the emitted electromagnetic radiation (S) and a high-frequency mixer frequency (F), on which the radiation remitted by the object and converted by a detector into high-frequency modulated electrical signals is superimposed and wherein the mixer frequency (F) differs from the modulation frequency by a frequency of a low-frequency measurement signal (NF) to be evaluated; regulating a frequency furnished by a quartz oscillator in a ring oscillator with N delay elements (V 1 , V 2 , V 3 , . . . , V N ) to provide the desired high-frequency mixer frequency (F), signals at the N delay elements (V 1 , V 2 , V 3 , . . . , V N ) being delivered to a multiplexer which is switched over at a cadence that corresponds to 2*N times the frequency of the low-frequency measurement signal (NF); and generating at the output of the multiplexer, the high-frequency modulation frequency (M,M*), which differs from the high-frequency mixer frequency (F) by the frequency of the low-frequency measurement signal (NF).