Pulse homodyne field disturbance sensor

Patent · Wed Jan 01 00:00:00 EST 1997

OSTI ID:871210

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 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.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA)
• Patent Number(s): US 5682164
• OSTI ID: 871210
• Country of Publication: United States
• Language: English

Related Subjects

pulse
homodyne
field
disturbance
sensor
operates
relatively
power
provides
adjustable
operating
range
hypersensitive
close
allows
co-location
multiple
sensors
inexpensive
manufacture
transmitter
transmits
sequence
transmitted
bursts
electromagnetic
energy
frequency
modulated
intermediate
burst
repetition
rate
width
comprises
cycles
receiver
receives
mixer
mixes
reflections
produce
signal
circuitry
responsive
indicates
disturbances
defines
randomly
pseudo-randomly
phase
varies
range-defining
mode
radio
time
spacing
maximum
divided
operating range
multiple sensors
repetition rate
radio frequency
electromagnetic energy
intermediate frequency
magnetic energy
frequency signal
sensor field
mixer mixes
sensor operates
close range
field disturbance
disturbance sensor
stable operating
allows co-location
adjustable operating
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