Homodyne impulse radar hidden object locator
Abstract
An electromagnetic detector is designed to locate an object hidden behind a separator or a cavity within a solid object. The detector includes a PRF generator for generating 2 MHz pulses, a homodyne oscillator for generating a 2 kHz square wave, and for modulating the pulses from the PRF generator. A transmit antenna transmits the modulated pulses through the separator, and a receive antenna receives the signals reflected off the object. The receiver path of the detector includes a sample and hold circuit, an AC coupled amplifier which filters out DC bias level shifts in the sample and hold circuit, and a rectifier circuit connected to the homodyne oscillator and to the AC coupled amplifier, for synchronously rectifying the modulated pulses transmitted over the transmit antenna. The homodyne oscillator modulates the signal from the PRF generator with a continuous wave (CW) signal, and the AC coupled amplifier operates with a passband centered on that CW signal. The present detector can be used in several applications, including the detection of metallic and non-metallic objects, such as pipes, studs, joists, nails, rebars, conduits and electrical wiring, behind wood wall, ceiling, plywood, particle board, dense hardwood, masonry and cement structure. The detector ismore »
- Inventors:
-
- Livermore, CA
- Issue Date:
- Research Org.:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- OSTI Identifier:
- 870399
- Patent Number(s):
- 5512834
- Assignee:
- Regents of University of California (Oakland, CA)
- Patent Classifications (CPCs):
-
G - PHYSICS G01 - MEASURING G01F - MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL
G - PHYSICS G01 - MEASURING G01S - RADIO DIRECTION-FINDING
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- homodyne; impulse; radar; hidden; locator; electromagnetic; detector; designed; locate; separator; cavity; solid; prf; generator; generating; mhz; pulses; oscillator; khz; square; wave; modulating; transmit; antenna; transmits; modulated; receive; receives; signals; reflected; receiver; path; sample; hold; circuit; coupled; amplifier; filters; dc; bias; level; shifts; rectifier; connected; synchronously; rectifying; transmitted; modulates; signal; continuous; cw; operates; passband; centered; applications; including; detection; metallic; non-metallic; pipes; studs; joists; nails; rebars; conduits; electrical; wiring; wood; wall; ceiling; plywood; particle; board; dense; hardwood; masonry; cement; structure; portable; light; weight; simple; inexpensive; power; emission; facilitates; compliance; 15; fcc; rules; impulse radar; light weight; circuit connected; continuous wave; receive antenna; dc bias; transmit antenna; square wave; hold circuit; rf generator; signals reflected; pulses transmitted; modulated pulse; electrical wiring; pulse radar; rectifier circuit; modulated pulses; antenna transmits; /324/342/
Citation Formats
McEwan, Thomas E. Homodyne impulse radar hidden object locator. United States: N. p., 1996.
Web.
McEwan, Thomas E. Homodyne impulse radar hidden object locator. United States.
McEwan, Thomas E. Mon .
"Homodyne impulse radar hidden object locator". United States. https://www.osti.gov/servlets/purl/870399.
@article{osti_870399,
title = {Homodyne impulse radar hidden object locator},
author = {McEwan, Thomas E},
abstractNote = {An electromagnetic detector is designed to locate an object hidden behind a separator or a cavity within a solid object. The detector includes a PRF generator for generating 2 MHz pulses, a homodyne oscillator for generating a 2 kHz square wave, and for modulating the pulses from the PRF generator. A transmit antenna transmits the modulated pulses through the separator, and a receive antenna receives the signals reflected off the object. The receiver path of the detector includes a sample and hold circuit, an AC coupled amplifier which filters out DC bias level shifts in the sample and hold circuit, and a rectifier circuit connected to the homodyne oscillator and to the AC coupled amplifier, for synchronously rectifying the modulated pulses transmitted over the transmit antenna. The homodyne oscillator modulates the signal from the PRF generator with a continuous wave (CW) signal, and the AC coupled amplifier operates with a passband centered on that CW signal. The present detector can be used in several applications, including the detection of metallic and non-metallic objects, such as pipes, studs, joists, nails, rebars, conduits and electrical wiring, behind wood wall, ceiling, plywood, particle board, dense hardwood, masonry and cement structure. The detector is portable, light weight, simple to use, inexpensive, and has a low power emission which facilitates the compliance with Part 15 of the FCC rules.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 1996},
month = {Mon Jan 01 00:00:00 EST 1996}
}