Abstract: A radar can detect target azimuths located outside and adjacent to a scanning angular range of a beam by determining changes in received signal strength (a signal-strength profile) in the azimuthal direction as a function of a beam azimuth in a predetermined scanning angular range, and estimating the target azimuth causing the signal-strength profile from the signal-strength profile, which is portion of a convex located adjacent to the outermost angle in the scanning angular range. For example, the target azimuth is estimated by a ratio between the received signal strength at the outermost angle of about 10.0° and the received signal strength at about 9.5°, which is one beam inside the outermost position.

Abstract: A radar system in which a beat signal is generated by transmitting a transmission signal that is subjected to frequency modulation into a triangular wave and receiving a reflection signal from a target, the beat signal is sampled, and a window function is applied to yield a discrete frequency spectrum. When the window function is applied, a first window function having an amplitude that is gently attenuated from the center of the sampling period toward both sides thereof is applied in a lower frequency band in the frequency spectrum (at close range), and a second window function having an amplitude that is sharply attenuated from the center of the sampling period toward both sides thereof is applied in a higher frequency band in the frequency spectrum (at far range).

Abstract: A radar can detect target azimuths located outside and adjacent to a scanning angular range of a beam determining changes in received signal strength (a signal-strength profile) in the azimuthal direction as a function of a beam azimuth in a predetermined scanning angular range, and estimating the target azimuth causing the signal-strength profile from the signal-strength profile, which is a portion of a convex located adjacent to the outermost angle in the scanning angular range. For example, the target azimuth is estimated by a ratio between the received signal strength at the outermost angle of about 10.0° and the received signal strength at about 9.5°, which is one beam inside the outermost position.

Abstract: An FM-CW radar detects at least one of the relative distance and the relative speed of a predetermined object based on the frequencies of projection portions observed in the frequency spectrums of beat signals in an ascending-modulation section and a descending-modulation section, where the projection portions are generated by one and the same object. The radar determines the moving speed of a predetermined moving object such as a vehicle or the like having the radar mounted thereon, and the frequency difference between the projection portions observed in the frequency spectrums of the beat signals in the ascending-modulation section and the descending-modulation section is inversely calculated, where the frequency difference corresponds to the stationary object, and a predetermined pair corresponding to the frequency difference is extracted on a priority basis.

Abstract: An FM-CW radar detects at least one of the relative distance and the relative speed of a predetermined object based on the frequencies of projection portions observed in the frequency spectrums of beat signals in an ascending-modulation section and a descending-modulation section, where the projection portions are generated by one and the same object. The radar determines the moving speed of a predetermined moving object such as a vehicle or the like having the radar mounted thereon, and the frequency difference between the projection portions observed in the frequency spectrums of the beat signals in the ascending-modulation section and the descending-modulation section is inversely calculated, where the frequency difference corresponds to the stationary object, and a predetermined pair corresponding to the frequency difference is extracted on a priority basis.

Abstract: A radar performs accurate and appropriate pairing even if peaks of approximately identical signal intensities or even if a plurality of peak groups having identical representative beam bearings exist in the frequency spectrum. First, the peak frequency of a peak which appears in the frequency spectrum is determined for each of an up-modulating interval and a down-modulating interval in predetermined beam bearings, and signal-intensity profiles in the beam bearings are extracted with regard to a plurality of beam portions which are adjacent to the beam bearings. Next, the correlation level between the signal-intensity profiles at the up-modulating interval and the down-modulating interval is determined, and pairing is performed in sequence starting from the profiles having a higher correlation level.

Abstract: A radar system achieves adjustment of a time-change characteristic of a frequency-modulating voltage signal to a voltage-controlled oscillator for determining a transmitting signal such that the time-change characteristic of the frequency-modulating voltage signal is changed by a minute amount and the frequency spectrum of a beat signal is determined. The adjustment is performed so that the shape of a bulge in signal intensity included in the frequency spectrum is the sharpest.

Abstract: In a radar, a coupler extracts a part of a transmission signal as a local signal and a mixer mixes a reception signal from a circulator and the local signal so as to output an intermediate frequency signal which is the frequency difference between the transmission signal and the reception signal. An IF-amplifying circuit amplifies the intermediate frequency signal and an AD converter converts the signal to digital data. A DC-removing unit removes a DC component by subtracting the average from the data and an FFT operation unit performs fast Fourier transform so that the distance to a target and the relative velocity of the target are calculated based on a peak included in the frequency spectrum.

Abstract: A radar system and a characteristic adjustment method for the radar system are provided, in which a control voltage waveform of a voltage controlled oscillator for frequency-modulating a sending signal can be set in a short time without increasing the required amount of memory. In adjusting time-varying characteristics of a voltage signal for frequency modulation on a voltage controlled oscillator determining a sending frequency, the time-varying characteristics of the voltage signal for frequency modulation are adjusted to optimize a form of a protrusion in signal intensity included in a frequency spectrum of a beat signal.

Abstract: In an FM-CW radar system, regarding peaks appearing in the frequency spectrum of a beat signal in an FM-CW radar, groups of consecutive peaks in beam bearings within a predetermined frequency difference are regarded as being caused by reflected waves from a single target, and based on a combination of a peak group in an up-modulating interval and a peak group in a down-modulating interval, a relative distance to a target and its relative speed are determined.

Abstract: A radar system is capable of transmitting necessary information through a very small amount of data from a radar device to a host device via a bus with a limited bandwidth. A radar sensor generates a beat signal between a transmission signal and a reflected signal from a target. A signal processor determines a spectrum of the beat signal and compresses the data indicating the spectrum. The resultant compressed data is transmitted to the host device via a bus. The host device decompresses the received data thereby reproducing the spectrum data. The host device then detects the target on the basis of the reproduced spectrum data.

Abstract: A radar device precisely detects a target in short time intervals by detecting a true peak frequency with high accuracy via a calculation which does not require a large amount of computation. A discrete frequency spectrum of a beat signal multiplied by a window function is determined, and values of signal strength at two discrete frequencies which are, respectively, higher and lower than a peak frequency of the discrete frequency spectrum of the beat signal and which are adjacent to the peak frequency. The frequency difference between the discrete peak frequency of the beat signal and the peak frequency of the window function is then determined from the ratio between the values of signal strength at those two discrete frequencies adjacent to the peak frequency. Thus, the true peak frequency of the beat signal is determined with a high frequency resolution.

Abstract: A radar system includes a transmitting/receiving unit, having a voltage controlled oscillator, for repeatedly transmitting a triangular transmission signal including a frequency-gradually-rising up-modulation interval and a frequency-gradually-dropping down-modulation interval and for receiving a reception signal including a reflected signal from a target, a frequency analysis unit, a data storing unit for storing time-varying characteristics of input values to a D/A converter that monotonically change an oscillation frequency of the voltage controlled oscillator with time, in the form of data concerning an expression representing the time-varying characteristics, and a data processing unit for determining the input values to the D/A converter with reference to the data. At least one of the relative distance to the target and the relative speed of the target is detected based on a beat signal during the up-modulation interval and the beat signal during the down-modulation interval.

Abstract: A radar system achieves adjustment of a time-change characteristic of a frequency-modulating voltage signal to a voltage-controlled oscillator for determining a transmitting signal such that the time-change characteristic of the frequency-modulating voltage signal is changed by a minute amount and the frequency spectrum of a beat signal is determined. The adjustment is performed so that the shape of a bulge in signal intensity included in the frequency spectrum is the sharpest.

Abstract: A radar system is capable of transmitting necessary information through a very small amount of data from a radar device to a host device via a bus with a limited bandwidth. A radar sensor generates a beat signal between a transmission signal and a reflected signal from a target. A signal processor determines a spectrum of the beat signal and compresses the data indicating the spectrum. The resultant compressed data is transmitted to the host device via a bus. The host device decompresses the received data thereby reproducing the spectrum data. The host device then detects the target on the basis of the reproduced spectrum data.

Abstract: A radar device precisely detects a target in short time intervals by detecting a true peak frequency with high accuracy via a calculation which does not require a large amount of computation. A discrete frequency spectrum of a beat signal multiplied by a window function is determined, and values of signal strength at two discrete frequencies which are, respectively, higher and lower than a peak frequency of the discrete frequency spectrum of the beat signal and which are adjacent to the peak frequency. The frequency difference between the discrete peak frequency of the beat signal and the peak frequency of the window function is then determined from the ratio between the values of signal strength at those two discrete frequencies adjacent to the peak frequency. Thus, the true peak frequency of the beat signal is determined with a high frequency resolution.

Abstract: A radar system includes a transmitting/receiving unit, having a voltage controlled oscillator, for repeatedly transmitting a triangular transmission signal including a frequency-gradually-rising up-modulation interval and a frequency-gradually-dropping down-modulation interval and for receiving a reception signal including a reflected signal from a target, a frequency analysis unit, a data storing unit for storing time-varying characteristics of input values to a D/A converter that monotonically change an oscillation frequency of the voltage controlled oscillator with time, in the form of data concerning an expression representing the time-varying characteristics, and a data processing unit for determining the input values to the D/A converter with reference to the data. At least one of the relative distance to the target and the relative speed of the target is detected based on a beat signal during the up-modulation interval and the beat signal during the down-modulation interval.

Abstract: By changing the direction of a detection radio-wave beam within a detection-angle range and by detecting reflected-signal intensities, wherein each of the reflected-signal intensities is detected for each predetermined unit angle, moving averages of the reflected-signal intensities are calculated by using an angular width predetermined for a given distance as an average width. Thus, data of a reflected-signal-intensity distribution is obtained. Accordingly, the direction of a target is detected by finding the direction of the highest reflected-signal intensity.

Abstract: A radar performs accurate and appropriate pairing even if peaks of approximately identical signal intensities or even if a plurality of peak groups having identical representative beam bearings exist in the frequency spectrum. First, the peak frequency of a peak which appears in the frequency spectrum is determined for each of an up-modulating interval and a down-modulating interval in predetermined beam bearings, and signal-intensity profiles in the beam bearings are extracted with regard to a plurality of beam portions which are adjacent to the beam bearings. Next, the correlation level between the signal-intensity profiles at the up-modulating interval and the down-modulating interval is determined, and pairing is performed in sequence starting from the profiles having a higher correlation level.

Abstract: In an FM-CW radar system, regarding peaks appearing in the frequency spectrum of a beat signal in an FM-CW radar, groups of consecutive peaks in beam bearings within a predetermined frequency difference are regarded as being caused by reflected waves from a single target, and based on a combination of a peak group in an up-modulating interval and a peak group in a down-modulating interval, a relative distance to a target and its relative speed are determined.