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Title:
パルス同期によるフィールド外乱センサ
Document Type and Number:
Japanese Patent JP3824655
Kind Code:
B2
Abstract:
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two.

Inventors:
Thomas E. McYuen
Application Number:
JP54241497A
Publication Date:
September 20, 2006
Filing Date:
May 05, 1997
Export Citation:
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Assignee:
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
International Classes:
G01S7/282; G01S13/12; G01S7/285; G01V3/12; G01S7/40; G01S13/02; G01S13/04; G01S13/18; G01S13/32; G01S13/34; G01S13/56; G08B13/181
Domestic Patent References:
JP4315979A
JP5002091U
JP5297122A
JP3191890A
Attorney, Agent or Firm:
Kazuo Sato
Asahi Maejima
Masami Tamama
Hidetoshi Tachibana