Radar designed to minimize error in detecting target
AssigneeDenso Corporation
InventorKazuma Natsume
Life of this patent
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Abstract
An FMCW radar is provided which may be employed in automotive anti-collision or radar cruise control systems. In a distance measuring mode, only one of channels is used to sample a beat signal continuously, thereby allowing a sampling frequency to be increased up to Nc times that in an azimuth measuring mode and a sweep time in which a transmit signal sweeps in frequency upward and downward cyclically to be minimized. This causes half the sampling frequency to be higher than a frequency component arising sufficiently from a distant target present outside a preset radar range, thereby eliminating an error in detecting the distant target as being located inside the preset radar range.
Claims9
A radar apparatus comprising:
- a transmit signal generator generating a transmit signal which is so modulated in frequency as to vary with time cyclically;
- a transceiver having a plurality of channels each of which is made up of a transmit antenna and a receive antenna, said transceiver outputting the transmit signal in the form of a radar wave and receiving a return of the radar wave from a target through any of the channels;
- a switching circuit switching one of the channels from another which is to be used in said transceiver, said switching circuit performing a first switching control mode and a second switching control mode within each cycle of frequency-modulation of the transmit signal, in the first switching control mode, all the channels being selected in sequence in a cycle, in the second switching control mode, a predetermined number of the channels being selected in a cycle;
- a beat signal generator mixing a signal received by said transceiver that is the return of the radar wave from the target with a local signal that has the same frequency as that of the transmit signal to generate a beat signal;
- and
- a signal processor sampling the beat signal produced by said beat signal generator and subjecting samples of the beat signal to a given signal processing operation to produce predetermined information about the target.
Dependencies are inferred from the claim text.