Radar system installable in an automotive vehicle for detecting a target object
First Claim
1. A radar system comprising:
- transmitting signal generating means for producing a high-frequency transmitting signal which is carried on a radar wave, said transmitting signal being frequency modulated in accordance with a linear modulation component and a cyclic modulation component, the transmitting signal generating means includingfirst component generating means for producing said linear modulation component, the linear modulation component varying a frequency of said transmitting signal linearly relative to time,second component generating means for producing said cyclic modulation component, the cyclic modulation component varying said frequency of said transmitting signal cyclically at a cyclic frequency larger than twice a frequency of a beat signal,adding means for adding said linear modulation component and said cyclic modulation component and producing a modulation signal, anda high-frequency oscillator producing said high-frequency transmitting signal whose frequency is variable in accordance with said modulation signal;
a high-frequency mixer for mixing a received signal of the radar wave reflected from a target object with a local signal derived from said transmitting signal produced from said transmitting signal generating means, and producing the beat signal, the beat signal being a signal having a frequency component representing a difference between said received signal and said local signal; and
calculating means for obtaining a distance from the radar system and a velocity relative to the radar system of said target object based on harmonic components of said beat signal produced when said transmitting signal is modulated by said cyclic modulation component.
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Accused Products
Abstract
A modulation signal generating section produces a modulation signal for controlling an oscillation frequency of a voltage-controlled oscillator. The modulation signal generating section comprises a triangular wave oscillator producing a linear modulation component of a triangular waveform which varies the modulation frequency linearly, a sine wave oscillator producing a cyclic modulation component of a sine waveform which varies the modulation frequency cyclically, and a signal adder producing the modulation signal by adding the linear modulation component and the cyclic modulation component. A transmitting signal frequency modulated by the modulation signal is mixed with a received signal and produces a beat signal comprising a fundamental wave component of a beat frequency and harmonic components.
126 Citations
19 Claims
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1. A radar system comprising:
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transmitting signal generating means for producing a high-frequency transmitting signal which is carried on a radar wave, said transmitting signal being frequency modulated in accordance with a linear modulation component and a cyclic modulation component, the transmitting signal generating means including first component generating means for producing said linear modulation component, the linear modulation component varying a frequency of said transmitting signal linearly relative to time, second component generating means for producing said cyclic modulation component, the cyclic modulation component varying said frequency of said transmitting signal cyclically at a cyclic frequency larger than twice a frequency of a beat signal, adding means for adding said linear modulation component and said cyclic modulation component and producing a modulation signal, and a high-frequency oscillator producing said high-frequency transmitting signal whose frequency is variable in accordance with said modulation signal; a high-frequency mixer for mixing a received signal of the radar wave reflected from a target object with a local signal derived from said transmitting signal produced from said transmitting signal generating means, and producing the beat signal, the beat signal being a signal having a frequency component representing a difference between said received signal and said local signal; and calculating means for obtaining a distance from the radar system and a velocity relative to the radar system of said target object based on harmonic components of said beat signal produced when said transmitting signal is modulated by said cyclic modulation component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A radar system comprising:
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transmitting signal generating means for producing a high-frequency transmitting signal which is frequency modulated so as to vary linearly relative to time and is carried on a radar wave; local signal generating means for producing a local signal based on a branch signal separated from said transmitting signal produced from said transmitting signal generating means; and a high-frequency mixer for mixing a received signal of the radar wave reflected from a target object with said local signal produced from said local signal generating means, and producing a beat signal having a frequency component representing a difference between said received signal and said local signal, wherein said local signal generating means comprises; local modulation signal generating means for producing a local modulation signal having a fundamental wave component whose frequency is larger than twice the frequency of the frequency component of the beat signal representing a difference between said local signal and said received signal; and branch signal modulating means for modulating an amplitude of said branch signal in accordance with said local modulation signal produced from said local modulation signal generating means to produce said local signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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Specification