Patent · US Expired

FM-CW radar apparatus for measuring relative speed of and distance to an object

US5731778A · kind A · utility

61Cited by
7References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 2, 1996
Grant dateMar 24, 1998
Priority date
Expiry dateDec 2, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S2013/93271
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An FM-CW radar which is suitable for automotive anti-collision systems, for example, is provided. This radar outputs a radar signal in the form of a triangular wave whose frequency is increased at a given rate and decreased at a given rate. A receiver receives a wave reflected from a target to produce a beat signal and takes the Fourier transform of the beat signal to determine peak frequency components thereof showing peaks in a frequency spectrum. The receiver also determines phases of the peak frequency components and selects at least one from the peak frequency components in a frequency-rising range wherein the frequency of the radar signal is increased and at least one from the peak frequency components in a frequency-falling range wherein the frequency of the radar signal is decreased which show substantially the same phase to pair them for determining the distance to and relative speed of the target based on the frequency of the paired peak frequency components.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.