DEVICE FOR SUPPRESSING VERY CLOSE INTERFERENCE ECHO SIGNALS IN OPTICAL PULSE COMPRESSION RADARS

摘要

A device for suppressing the interference echo signals in an optical pulse compression radar comprising, at the transmitting side, a circuit for generating electrical signals of determined duration and with a frequency variable as a function of time, called chirps, an optical transmitter comprising a continuous transmission source modulated by the chirps and, at the receiving side, a receiver for deriving chirps from the light signals received and a processing circuit for the chirps supplied by the receiver, comprising a first mixer receiving from said receiver the reception chirp and from said circuit the transmission chirp and then, when the latter is ended, a relay signal of a determined frequency, said first mixer delivering a signal of a frequency equal to the difference of the frequencies of the input signals, a filter for filtering out the interference component of the output signal from the first mixer, and a second mixer receiving, on the one hand, the signal thus filtered and, on the other hand, the transmission chirp and then said relay signal, and delivering to said processing circuit a signal of a frequency equal to the difference of the frequencies of the input signals.