Abstract: A modulation signal generation circuit performs frequency modulation of a VCO with a triangular wave for operation as an FM-CW radar. A signal processing circuit gives a modulation signal for detection generated from the modulation signal generation circuit to the VCO. A high-frequency signal subjected to frequency modulation in the VCO is transmitted as a radio wave from a transmission antenna and is reflected on a target and the reflected radio wave is received at a reception antenna. The reception signal and the high-frequency signal are mixed by a mixer to provide a beat signal and frequency shift corresponding to a voltage V1 is detected from the frequency of the beat signal. If the voltage V1 of the modulation signal for detection is switched, the frequency shift corresponding to different voltage V1 can be provided and the frequency modulation characteristic can be detected.

Abstract: The present invention relates to a radar device and, particularly, to a radar device mounted on a vehicle to be used for a collision alarm and the like. The invention provides a radar device that has a unit for removing the FMAM noise without lowering the signal detection sensitivity. The radar device transmits a frequency modulation signal by switching the frequency modulation signal with a first switching signal, receives a signal reflected from a target object, switches the reception signal with a second switching signal, mixes the switched reception signal with the transmission signal, and further mixes the mixed signals with a third switching signal thereby to obtain a beat signal. The radar device obtains a distance to the target object and a relative speed of the target object from the beat signal.

Abstract: As to a beat signal of a received wave, for instance, a plurality of FFT-based frequency spectra of every FM rise zone are accumulated in an accumulation unit. A judgment unit judges a valley section from the plurality of frequency spectra accumulated. A peak frequency extraction unit acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of the valley sections judged.

Abstract: A modulation signal generation circuit performs frequency modulation of a VCO with a triangular wave for operation as an FM-CW radar. A signal processing circuit gives a modulation signal for detection generated from the modulation signal generation circuit to the VCO. A high-frequency signal subjected to frequency modulation in the VCO is transmitted as a radio wave from a transmission antenna and is reflected on a target and the reflected radio wave is received at a reception antenna. The reception signal and the high-frequency signal are mixed by a mixer to provide a beat signal and frequency shift corresponding to a voltage V1 is detected from the frequency of the beat signal. If the voltage V1 of the modulation signal for detection is switched, the frequency shift corresponding to different voltage V1 can be provided and the frequency modulation characteristic can be detected.

Abstract: In an FM-CW radar system, a frequency modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control, the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON-OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.

Abstract: A radar mount direction alignment device to be used for aligning the transmit/receive direction of a radar device 2D mounted on a member on which a radar device is to be mounted, such as a vehicle 1. The radar mount direction alignment device has receiving sections b9, b10 for receiving a signal emitted from the radar device 2D, and transmission sections a9, a10 for transmitting a signal to the radar device 2D. The radar mount direction alignment device has the function of emitting, toward the radar device 2D, a signal which, upon receipt of a signal output from the radar device 2D, behaves as if having been received at and reflected from a position farther from the radar device 2D than a distance between the radar device 2D and the radar mount direction alignment device.

Abstract: A single antenna is used so that time-division transmission and reception is carried out in a radar apparatus for obtaining a distance and a relative speed with respect to a target object based on a beat signal obtained by transmitting a frequency modulated signal and mixing a received signal reflected by said target object with the frequency modulated signal that is transmitted.

Abstract: A high frequency signal, which is produced in a oscillator, is modulated by a frequency from a modulating signal generated by a modulation signal generator and radiated from a sending antenna. A reflected signal from a target object is received by a receiving antenna, and frequency-converted by a local oscillating signal from a directional coupler in the frequency convertor. Then, distance and speed information is detected by a signal processing unit. A modulator, which is connected to the oscillator, modulates the oscillator output in order to detect a failure. A detection unit, in which a filter unit, a rectification circuit, and a voltage comparison circuit are included, detects modulated elements originated in the above described modulator. The signal processing unit makes a failure determination based on the modulated elements which have already been detected.

Abstract: A radar apparatus for detecting a distance/velocity has a transmitting system for transmitting a signal which is frequency-modulated with a modulating signal having a predetermined recurrence frequency, a receiving system for receiving a reflected wave signal, which is the modulated transmission signal transmitted from the transmitting system and reflected by an object, and which mixes the reflected wave signal and the modulated transmission signal from the transmitting system so as to detect a beat wave signal of the reflected wave signal and the modulated transmission signal.

Abstract: A FM-CW radar device is provided for frequency-modulating a high frequency signal with a modulation signal, transmitting the modulated high frequency signal, receiving a signal reflected by a target object and frequency-modulating the reflection signal with a signal generated by a local oscillator signal source provided by branching a portion of the transmitting signal. A modulator is disposed between a radar transmitting section and a transmitting antenna. The modulator modulates the transmitting signal with a second frequency which is far lower than the radar transmitting frequency and twice as much as the sum or the difference of a Doppler frequency generated by a relative propagation velocity and a beat frequency generated by a propagation delay time. A first frequency converter frequency modulates the received signal reflected by the target object with the local oscillator.