| 摘要 |
PROBLEM TO BE SOLVED: To provide an FMCW (frequency-modulated continuous wave) radar device which securely detects a target moving at close range at a high relative velocity. SOLUTION: A signal (consequently radar waves) generated by a VCO (voltage-controlled oscillator) 10 according to a modulation signal M generated by a signal processing part 22 is set so that a modulation period of time TD1 for linearly decreasing the frequency at a first variation rate A1, in the modulation rangeΔF, and a modulation period of time TD2 for linearly decreasing the frequency at a second variation rate A2, in the same modulation rangeΔF, are repeated. The distance to the target or the relative velocity is obtained, on the basis of the beat frequency detected in the modulation periods TD1 and TD2 and the ratio N(=A2/A1) of the two variation rates. Because the frequency is set to decrease gradually, in both the modulation periods TD1 and TD2, loop back of the beat frequency with respect to the approaching target will not be generated, thereby surely enabling detection of the approaching target. COPYRIGHT: (C)2004,JPO
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