The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 2017
Filed:
Dec. 23, 2014
Kabushiki Kaisha Toyota Chuo Kenkyusho, Nagakute-shi, Aichi-ken, JP;
Daisuke Inoue, Nagakute, JP;
Tatsuya Yamashita, Nagakute, JP;
Tadashi Ichikawa, Nagakute, JP;
Satoru Kato, Nagakute, JP;
Kazuo Hasegawa, Nagakute, JP;
KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, Nagakute-shi, JP;
Abstract
A radar apparatus which can simply determine the sign of velocity of an object is provided. Laser light reflected by the object undergoes quadrature optical heterodyne detection performed by mixers, optical detectors, and a π/2 phase shifter, whereby I and Q component signals are output. A frequency analyzer performs FFT on a complex signal composed of the I component signal (real part) and the Q component signal (imaginary part) to thereby obtain its frequency spectrum. Since the frequency spectrum is calculated without being folded back even in a region where the frequency is negative, the sign of the Doppler frequency fd can be determined. When the Doppler frequency fd is positive, the sign of the velocity of the object is a direction toward the radar apparatus. When the Doppler frequency fd is negative, the sign of the velocity of the object is a direction away from the radar apparatus.