Abstract: A radar device includes a transmit antenna radiating a modulation signal and a receive antenna receiving reflection waves from the modulation signal. The radar device also includes a mixer mixing the modulation signal and the received signal to output a beat signal, a calculation circuit judging presence or absence of an abnormality by using the beat signal, and a memory storing reference data and a threshold. The reference data indicates a phase component of a set frequency signal from a beat signal without necessarily any abnormality. The set frequency signal is generated from the modulation signal reflected on a surface of a housing located at a set distance from the radar device. The calculation circuit extracts a phase component from the beat signal and supplies information indicating the presence of an abnormality if the difference between the extracted phase component and the reference data is greater than the threshold.

Abstract: A communication device is capable of estimating an incoming wave number with high accuracy. A communication device includes an antenna and circuitry configured to calculate an arrival direction of a reception signal received from the antenna in a case of a predetermined incoming wave number based on the reception signal and the predetermined incoming wave number, calculate an incoming signal for each of one or more arrival directions in a case of a certain incoming wave number based on the incoming wave number and the one or more arrival directions, and estimate an incoming wave number of the reception signal based on levels of the incoming signals in a plurality of arrival directions.

Abstract: A radar device includes an oscillator that generates a transmission signal including a plurality of chirp signals, the chirp signal having a frequency that increases or decreases from an initial frequency in each predetermined sweep cycle. The oscillator changes the initial frequency of each chirp signal. A transmitter emits the transmission signal, and a receiver receives a reflected wave of the transmission signal reflected at an object and an unwanted wave as a reception signal. Circuitry is configured to estimate a phase of the reception signal from the transmission signal and the reception signal, calculate a correlation between a change pattern of the initial frequency of each chirp signal and a change pattern of the phase of the reception signal, estimate the reflected wave from the reception signal based on the correlation, and calculate a number of incoming waves based on a result of the estimation of the reflected wave.

Abstract: A communication apparatus capable of estimating the number of incoming waves with high accuracy is provided. A communication apparatus includes an antenna, a matrix calculator that calculates, based on reception signals received from the antenna, a first matrix having singular values of a reception signal matrix, a matrix calculator that extracts reception signals whose frequency is within a specific frequency range from the reception signals and calculates, based on the extracted reception signals, a second matrix having singular values of a second reception signal matrix, and a number-of-incoming-waves estimator that estimates, based on the first matrix and the second matrix, the number of incoming waves of the reception signals.

Abstract: Provided is a radar device that may perform an angle estimation of an incoming direction of an incoming wave with high accuracy because of increased angular resolution and has an increased dynamic range. In a transmission antenna Tx, transmission antenna elements Tx1, Tx2, Tx3, and the like of number m of three or more are arranged in a straight line at equal intervals of wavelength ? of a transmission wave. In a reception antenna Rx, reception antenna elements Rx1, Rx2, and the like, are arranged in a straight line at equal intervals. Circuitry generates virtual reception antenna elements Rxa, Rxb, . . . , and Rxq between the respective reception antenna elements by adjusting a phase of a reception signal to control the directivity of a radio wave to perform beam-forming between transmission antenna elements in each pair.

Abstract: A receiver accurately performs, using an annihilation filter, angle estimation in two-dimensional directions of an incoming wave. The receiver operates with at least two linear array antenna. The receiver may be implemented in a radar apparatus includes the receiver, as well as a vehicle and a communication system, which also include the receiver.

Abstract: A radar apparatus is constituted by a transmitter including transmit antennas, and a receiver including receive antennas, and processing circuitry. When a first beam pattern is used for detection, a memory of the receiver stores as a first result a detection result indicating the position of a reflection point of radio wave. When a second beam pattern is used for detection, a memory of the receiver stores as a second result a detection result indicating the position of a reflection point of radio wave. A detection-result comparator of the receiver compares the first and second results. When the position of a reflection point of the first result is different from the position of the reflection point of the second result, the detection-result comparator removes the reflection point that differs in position.

Abstract: A radar device includes a transmit antenna radiating a modulation signal and a receive antenna receiving reflection waves from the modulation signal. The radar device also includes a mixer mixing the modulation signal and the received signal to output a beat signal, a calculation circuit judging presence or absence of an abnormality by using the beat signal, and a memory storing reference data and a threshold. The reference data indicates a phase component of a set frequency signal from a beat signal without necessarily any abnormality. The set frequency signal is generated from the modulation signal reflected on a surface of a housing located at a set distance from the radar device. The calculation circuit extracts a phase component from the beat signal and supplies information indicating the presence of an abnormality if the difference between the extracted phase component and the reference data is greater than the threshold.

Abstract: A detection component of a reflected wave generated due to a transmitted wave being reflected inside a radome is removed from a measurement intermediate frequency signal IF? obtained by a mixer circuit when measuring the position of an object, the detection component of the reflected wave being removed by a radome reflection correcting unit subtracting a difference Diff. stored in advance in a correction data storage unit. In addition, when the radome reflection correcting unit performs the subtraction, the phase of the result of the subtraction is corrected by a phase shift amount ej?? calculated by the phase shift amount calculating unit so that a phase shift of a measurement intermediate frequency signal IF? caused by the device temperature is corrected. A distance/angle computing unit computes the position of the object from the thus-corrected measurement intermediate frequency signal IF?.

Abstract: An antenna apparatus includes multiple antenna elements each performing at least one of transmission and reception of radio waves. The coverage areas of main lobes of radiation patterns of the multiple antenna elements are overlapped with each other and the shapes of side lobes thereof are varied among the multiple antenna elements. With this configuration, it is possible to discriminate and acquire the signal of the radio waves coming from the coverage areas of the main lobes of the antenna from the signal of the radio waves coming from the outside of the coverage areas.