Radar device
AssigneeFujitsu Limited
InventorsKaoru Yokoo, Yasuyuki Oishi
Life of this patent
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Abstract
The invention relates to a radar device for measuring a relative distance to a target. It is an object of the invention to precisely determine the relative distance to the target in a wide range. The radar device according to the invention generates a second pulse by demodulating a signal arriving from a target as a response to a wave signal modulated with a first pulse. The radar device evaluates, as the relative distance to the target, such two different instances that an absolute value of a deviation of a ratio of two instantaneous values of the second pulse from a reference value as a ratio of two instantaneous values of the first pulse is to be minimum. The respective two instantaneous values are with a predetermined interval therebetween on a time axis.
Claims20
A radar device comprising:
- a receiving section demodulating a signal which arrives from a target as a response to a wave signal modulated with a first pulse signal, to generate a second pulse signal;
- a signal specifying section specifying such two different instances that an absolute value of a deviation of a ratio of two instantaneous values of the second pulse signal from a reference value as a ratio of two instantaneous values of the first pulse signal is to be minimum, the two instantaneous values of the first and second pulse signals being with a predetermined interval therebetween on a time axis;
- and
- a distance evaluating section evaluating a relative distance to the target as a difference between a reference instance and one of specified two different instances or an instance near the specified two different instances, the reference instance being an instance at which the wave signal is transmitted on the time axis.
A radar device comprising:
- a receiving section demodulating a signal which arrives from a target as a response to a wave signal modulated with a first pulse signal, to generate a second pulse signal;
- a signal specifying section specifying such an instance that a correlation between a sequence of ratios of instantaneous values of the second pulse signal and a characteristic quantity is to be maximum, the characteristic quantity being a sequence of ratios of three or more instantaneous values of the first pulse signal, the instantaneous values of the first and second pulse signals being with a predetermined interval therebetween on a time axis;
- and
- a distance evaluating section evaluating a relative distance to the target as a difference between a reference instance and a specified instance or an instance near the specified instance, the reference instance being an instance at which the wave signal is transmitted on the time axis.
Dependencies are inferred from the claim text.