Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Yoshihiro Abe

Akiyoshi Mizutani

Kazuma Natsume

Yoshie Samukawa

Atsushi Kawakubo

Shinichiro Matsuzawa

Klas Alenljung

Toshiaki Watanabe

An antireflection structure includes an antireflection film provided on a front surface of a substrate. The antireflection film has a plurality of holes that are spatially and periodically arranged and pass through front and back surfaces of the antireflection film. A thickness and a relative dielectric constant of the antireflection film are set according to a relative dielectric constant and a thickness of the substrate and an incident angle &#x3b8; of an electromagnetic wave. The thickness and the relative dielectric constant of the antireflection film are set for an electromagnetic wave incident at the angle &#x3b8; so that, for example, an electromagnetic wave reflected by the antireflection film provided on the front surface of the substrate and an electromagnetic wave reflected by a back surface of the substrate deviate from each other by a half wavelength and cancel each other.

Antireflection structure and method of manufacturing the same

A radar apparatus includes: a transmitting portion including transmitter elements that emits a transmitting signal as a radar wave toward an object; a receiving portion including receiver elements receiving a reflection signal; and an estimation portion. The estimation portion generates a virtual receiving array including virtual receiver elements. The estimation portion divides the virtual receiving array into identical sub-arrays. The estimation portion generates covariance matrix data for each of the sub-arrays. The estimation portion averages the covariance matrix data for each of the sub-arrays to decorrelate a direct reflection signal from the object and multipath reflection signal among the reflection signal and spatially smooths the reflection signal. The estimation portion resolves the direct reflection signal from the object and the multipath reflection signal. The estimation portion determines the direction of the object.

Radar apparatus

A radar apparatus includes a transmitter, a receiver, and a signal processor. The transmitter outputs a radar wave. The receiver includes a plurality of receiving antennas and a plurality of receiving devices. Each of the receiving devices mixes a reception signal from the corresponding receiving antenna with a local signal and outputs a beat signal. The signal processor samples the beat signal while selecting one of the receiving devices in order with a selecting period that is less than a half of a sampling period. The signal processor samples the beat signal with the sampling period and derives position information of a target by pair matching of peaks of a rising-modulation signal and a falling-modulation signal of the beat signal.

A radar system for detecting positions of targets using a high resolution algorithm is presented. The number of incorrect target detections due to incorrect estimation of the number of radar reflections is reduced. A two-dimensional (azimuth and distance) peak having maximum power is detected, and a virtual beam formed centering on that peak. If that two-dimensional peak is buried in the virtual beam it is assumed to be a noise peak and removed. This is repeated for all two-dimensional peaks, thereby removing noise peaks and reducing the number of unnecessary target detections. The system can also correctly detect peaks that are close together at a certain resolution but have a power larger than the virtual beam.

Radar system

A radar sensor receives a radar wave signal through a radome in each of antennas while judging existence of an attenuating thing in a detecting unit. This unit extracts a maximum level channel from receiving channels assigned to the antennas every modulation period, calculates a difference in signal level between the maximum level channel and each receiving channel every modulation period, sets each receiving channel corresponding to large level differences in one measuring period including plural modulation periods as a candidate channel every measuring period, increments a preliminary variable of each candidate channel every measuring period, increases a final variable each time the preliminary variable of at least one receiving channel reaches or exceeds a preliminary value in one measuring period, and judges in response to the final variable reaching a final value that the attenuating thing attenuates the radar wave directed toward the random.

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Kariya, Japan

Yoshihiro Abe