Range-gated field disturbance sensor with range-sensitivity compensation

Patent · Sun Dec 31 23:00:00 EST 1995

OSTI ID:870437

McEwan, Thomas E ^[1]

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1. Livermore, CA

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 pseudorandomly modulated so that bursts in the sequence of bursts have a phase which varies.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA)
• Patent Number(s): US 5521600
• OSTI ID: 870437
• Country of Publication: United States
• Language: English

Related Subjects

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adjustable
adjustable operating
allows
allows co-location
burst
bursts
circuitry
close
close range
co-location
compensation
comprises
cycles
defines
disturbance
disturbance sensor
disturbances
electromagnetic
electromagnetic energy
energy
field
field disturbance
frequency
frequency signal
gated field
hypersensitive
indicates
inexpensive
intermediate
intermediate frequency
magnetic energy
manufacture
mixer
mixer mixes
mixes
modulated
multiple
multiple sensors
operates
operating
operating range
phase
power
produce
provides
pseudorandomly
randomly
range
range-gated
range-sensitivity
rate
receiver
receives
reflections
relatively
repetition
repetition rate
responsive
sensor
sensor field
sensor operates
sensors
sequence
signal
stable operating
transmits
transmitted
transmitter
varies
width