Patent ID: 11874396
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A radar device that is configured to detect an abnormality, comprising:
a transmitter configured to generate a modulation signal;
a transmit antenna configured to radiate the modulation signal;
a receive antenna configured to receive waves generated by reflection of the modulation signal, as a received signal;
a mixer that is connected to the transmit antenna and to the receive antenna, and that is configured to mix the modulation signal and the received signal so as to output a beat signal;
a calculation circuit configured to determine a presence or absence of an abnormality based on the beat signal, reference data, and a threshold; and
a memory configured to store the reference data, correction data, and the threshold, wherein:
the reference data comprises information of a phase component of a set frequency signal, the phase component being a phase component of a beat signal when there is no abnormality concerning the radar device,
the correction data is for correcting a change in a phase component of the set frequency signal caused by a temperature of the radar device
the set frequency signal is a signal generated as a result of the modulation signal radiated from the transmit antenna and reflected on a surface of a housing, the housing storing the radar device therein, the surface of the housing being a set distance from the radar device, and
the calculation circuit is configured to determine the presence or absence of the abnormality by:
reading the reference data and the threshold from the memory,
obtaining the beat signal from the mixer,
obtaining temperature data when the beat signal is obtained,
extracting a phase component of the set frequency signal from the beat signal,
correcting the extracted phase component based on the correction data and the temperature data after the phase component is extracted, and
supplying information indicating the presence of the abnormality when a difference between the corrected phase component and the phase component of the reference data is greater than the threshold.