A method for determining and adjusting of the intermediate frequency in the case of frequency pulse radar systems - - - - and frequency pulse radar system

摘要

A method for determining and adjusting of the intermediate frequency in the case of a frequency - pulse - a radar system (1), in which• a frequency controllable oscillator (vco), both as transmitter - as well as a local oscillator for mixing of the received signals (e (t)) is used,• for the pulsed frequency modulation between two frequencies (f_Tx, f_Lo) direction - and forth about the thus defined intermediate frequency (f_If) distinguish,• one of these two frequencies (f_Tx), preferably the in comparison to the other is considerably shorter controlled frequency, the original pulses (s (t)) defined,• at the other frequency (f_Lo) selectively according to the distance, in so-called distance gates, is received,• the received signals (e (t)) and a possibly be transformed from a plurality of filters, consisting of an intermediate frequency filter (bp) passing through, the middle of at least approximately the optimum intermediate frequency, characterized by maximum system sensitivity, and• one or more antenna beams are used, characterized in thata) by a corresponding change of at least one control variable (v_Tune) of the oscillator (vco) for at least one of the two frequencies used for frequency modulation (f_Tx, f_Lo) a tuning of the intermediate frequency (f_If) by means of a region containing its optimal value is carried out, preferably so fast that during this process, the change in the entire target situation and of the reflectivity displacement holding of the individual targets is only very slight,b) in one or more antenna beams in one or more distance gates with a target, while its transit time of the oscillator frequency in each case has been switched over, which extends over the at least one through tuned oscillator expensive size (v_Tune) the curve of the (p (m)) according to the intermediate frequency filter (bp) is determined,c) one or more of such power traces (p (m)) in one or more radar cycles are evaluated in order to determine the power maximum,d) belonging to this power maximum values of the at least one oscillator expensive size (v_Tune) be determined,e) with the aid of these values of the at least one oscillator expensive size (v_Tune) the intermediate frequency (f_If) is adjusted.