Pulse homodyne field disturbance sensor
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. 12 figs.
- Inventors:
- Issue Date:
- Research Org.:
- Univ. of California (United States)
- Sponsoring Org.:
- USDOE, Washington, DC (United States)
- OSTI Identifier:
- 541746
- Patent Number(s):
- 5682164
- Application Number:
- PAN: 8-654,407
- Assignee:
- Univ. of California, Oakland, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Patent
- Resource Relation:
- Other Information: PBD: 28 Oct 1997
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; MEASURING INSTRUMENTS; RADIOWAVE RADIATION; FREQUENCY MODULATION; DISTURBANCES; DESIGN; RADIO EQUIPMENT
Citation Formats
McEwan, T E. Pulse homodyne field disturbance sensor. United States: N. p., 1997.
Web.
McEwan, T E. Pulse homodyne field disturbance sensor. United States.
McEwan, T E. Tue .
"Pulse homodyne field disturbance sensor". United States.
@article{osti_541746,
title = {Pulse homodyne field disturbance sensor},
author = {McEwan, T E},
abstractNote = {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. 12 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Oct 28 00:00:00 EST 1997},
month = {Tue Oct 28 00:00:00 EST 1997}
}