| Pat.#6002708: |
Spread spectrum
localizers |
| INVENTORS: |
Fleming; Robert Alan,
Nicasio, CA |
| |
Kushner; Cherie Elaine,
Nicasio, CA |
| ASSIGNEES: |
Aether Wire &
Location, Nicasio, CA |
| ISSUED: |
December 14, 1999 |
| FILED: |
May 23, 1997 |
| ABSTRACT:
A network of localizers determines relative locations in
three-dimensional space to within 1 cm by cooperatively measuring propagation
times of pseudorandom sequences of electromagnetic impulses. Ranging transmissions
may include encoded digital information to increase accuracy. The propagation
time is determined from a correlator circuit which provides an analog pseudo-autocorrelation
function sampled at discrete time bins.The correlator has a number of integrators,
each integrator providing a signal proportional to the time integral of
the product of the expected pulse sequence delayed by one of the discrete
time bins, and the non-delayed received antenna signal. With the impulses
organized as doublets the sampled correlator output can vary considerably
in shape depending on where the autocorrelation function peak falls in
relation to the nearest bin. Using pattern recognition the time of arrival
of the received signal can be determined to within a time much smaller
than the separation between bins. Because operation of standard CMOS circuitry
generates noise over a large frequency range, only low-noise circuitry
operates during transmission and reception. To provide the time accuracy
necessary for distancing, a high-frequency clock operates during inter-localizer
communications. The high-frequency clock uses a phase-lock loop circuit
to increase the clock rate and a programmable delay to provide still finer
time graduations. A stage in the low-frequency clock uses low-noise circuitry
during transmissions and receptions, and standard circuitry at other times. |
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|
|
| Pat.#5748891: |
Spread spectrum
localizers |
| INVENTORS: |
Fleming; Robert Alan,
Nicasio, CA |
| |
Kushner; Cherie Elaine,
Nicasio, CA |
| ASSIGNEES: |
Aether Wire &
Location, Nicasio, CA |
| ISSUED: |
May 5 , 1998 |
| FILED: |
July 22, 1994 |
| ABSTRACT:
A network of localizers determines relative locations in
three-dimensional space to within 1 cm by cooperatively measuring propagation
times of pseudorandom sequences of electromagnetic impulses. Ranging transmissions
may include encoded digital information to increase accuracy. The propagation
time is determined from a correlator circuit which provides an analog pseudo-autocorrelation
function sampled at discrete time bins. The correlator has a number of
integrators, each integrator providing a signal proportional to the time
integral of the product of the expected pulse sequence delayed by one of
the discrete time bins, And the non-delayed received antenna signal. With
the impulses organized as doublets the sampled correlator output can vary
considerably in shape depending on where the autocorrelation function peak
falls in relation to the nearest bin. Using pattern recognition the time
of arrival of the received signal can be determined to within a time much
smaller than the separation between bins. Because operation of standard
CMOS circuitry generates noise over a large frequency range, only low-noise
circuitry operates during transmission and reception. To provide the time
accuracy necessary for distancing, a high-frequency clock operates during
inter-localizer communications. The high-frequency clock uses a phase-lock
loop circuit to increase the clock rate and a programmable delay to provide
still finer time graduations. A stage in the low-frequency clock uses low-noise
circuitry during transmissions and receptions, and standard circuitry at
other times. |
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|
|
| Pat.#5687169: |
Full duplex ultrawide-band
communication system and method |
| INVENTORS: |
Fullerton; Larry W.,
Huntsville, AL |
| ASSIGNEES: |
Time Domain Systems,
Inc., Huntsville, AL |
| ISSUED: |
Nov. 11, 1997 |
| FILED: |
Apr. 27, 1995 |
| ABSTRACT:
An impulse radio transceiver for full duplex ultrawide-band
communications. The transceiver comprises an impulse radio transmitter
to transmit impulse radio signal pulses, an impulse radio receiver to receive
impulse radio signal pulses. Either or both of the impulse radio transmitter
and the impulse radio receiver, synchronizes the transmission and the reception
of the impulse radio signal pulses for pulse interleaved communications.
Pulse interleaving avoids self-interference between the transmitted impulse
radio signal pulses and the received impulse radio signal pulses. In addition
to pulse interleaved communications, bursts of pulses can be transmitted
between two transceivers in an interleaved fashion. Alternatively, two
different pulse repetition rates are be used to transmit and receive impulse
radio signal pulses simultaneously. Still further, selected pulses of the
received or transmitted impulse radio signal pulses are blanked to avoid
interference. |
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|
|
| Pat.#5682164: |
Pulse homodyne
field disturbance sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| FILED: |
May 28, 1996 |
| ABSTRACT:
A field disturbance sensor operates with relatively low power,
provides an adjustable operating range, is not hyper-sensitive 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. |
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|
|
| Pat.#5677927: |
Ultrawide-band
communication system and method |
| INVENTORS: |
Fullerton; Larry W.,
Huntsville, AL |
| |
Cowie; Ivan A., Madison,
AL |
| ASSIGNEES: |
Pulson Communications
Corporation, McLean, VA |
| ISSUED: |
Oct. 14, 1997 |
| FILED: |
Sep. 20, 1994 |
| ABSTRACT:
An impulse radio communications system using one or more
subcarriers to communicate information from an impulse radio ransmitter
to an impulse radio receiver. The impulse radio communication system is
an ultrawide-band time domain system. The use of subcarriers provides impulse
radio transmissions added channelization, smoothing and fidelity. Subcarriers
of different frequencies or waveforms can be used to add channelization
of impulse radio signals. Thus, an impulse radio link can communicate many
independent channels simultaneously by employing different subcarriers
for each channel. The impulse radio uses modulated subcarrier(s) for time
positioning a periodic timing signal or a coded timing signal. Alternatively,
the coded timing signal can be summed or mixed with the modulated subcarrier(s)
and the resultant signal is used to time modulate the periodic timing signal.
Direct digital modulation of data is another form of subcarrier modulation
for impulse radio signals. Direct digital modulation can be used alone
to time modulate the periodic timing signal or the direct digitally modulated
the periodic timing signal can be further modulated with one or more modulated
subcarrier signals. Linearization of a time modulator permits the impulse
radio transmitter and receiver to generate time delays having the necessary
accuracy for impulse radio communications. |
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|
|
| Pat.#5673050: |
Three-dimensional
underground imaging radar system |
| INVENTORS: |
Moussally; George,
Fremont, CA 94555-1117 |
| |
Ziernicki; Robert,
Los Altos, CA 94022 |
| |
Fialer; Philip A.,
Palo Alto, CA 94303 |
| |
Heinzman; Fred Judson,
Los Altos, CA 94024 |
| ASSIGNEES: |
none |
| ISSUED: |
Sep. 30, 1997 |
| FILED: |
June 14, 1996 |
| ABSTRACT:
An ultra-wide band ground penetrating radar (GPR) system
providing non-invasive detection and three-dimensional mapping of underground
objects and voids. The performance of this radar provides improved underground
object detection, location and identification over existing radars through
the use of a novel interrupted, frequency modulated, continuous wave (FMCW)
signal waveform. A synthetic aperture radar (SAR) technique known as spotlight
mode focused (SAR) operation is used to collect data for the underground
area of interest, by circumscribing this area with a radar beam provided
on an airborne or ground based vehicle. Near-Brewster angle illumination
of the ground is used to reduce losses. |
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|
|
| Pat.#5661490: |
Time-of-flight
radio location system |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| FILED: |
April 23, 1996 |
| ABSTRACT:
A bi-static radar configuration measures the direct time-of-flight
of a transmitted RF pulse and is capable of measuring this time-of-flight
with a jitter on the order of about one pico-second, or about 0.01 inch
of free space distance for an electromagnetic pulse over a range of about
one to ten feet. A transmitter transmits a sequence of electromagnetic
pulses in response to a transmit timing signal, and a receiver samples
the sequence of electromagnetic pulses with controlled timing in response
to a receive timing signal, and generates a sample signal in response to
the samples. A timing circuit supplies the transmit timing signal to the
transmitter and supplies the receive timing signal to the receiver. The
receive timing signal causes the receiver to sample the sequence of electromagnetic
pulses such that the time between transmission of pulses in the sequence
and sampling by the receiver sweeps over a range of delays. The receive
timing signal sweeps over the range of delays in a sweep cycle such that
pulses in the sequence are sampled at the pulse repetition rate, and with
different delays in the range of delays to produce a sample signal representing
magnitude of a received pulse in equivalent time. Automatic gain control
circuitry in the receiver controls the magnitude of the equivalent time
sample signal. A signal processor analyzes the sample signal to indicate
the time-of-flight of the electromagnetic pulses in the sequence. The sample
signal in equivalent time is passed through an envelope detection circuit,
formed of an absolute value circuit followed by a low pass filter, to convert
the sample signal to a unipolar signal to eliminate effects of antenna
misorientation. |
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|
|
| Pat.#5661385: |
Window-closing
safety system |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| FILED: |
August 3, 1995 |
| ABSTRACT:
A safety device includes a wire loop embedded in the glass
of a passenger car window and routed near the closing leading-edge of the
window. The wire loop carries microwave pulses around the loop to and from
a transceiver with separate output and input ports. An evanescent field
only an inch or two in radius is created along the wire loop by the pulses.
Just about any object coming within the evanescent field will dramatically
reduce the energy of the microwave pulses received back by the transceiver.
Such a loss in energy is interpreted as a closing area blockage, and electrical
interlocks are provided to halt or reverse a power window motor that is
actively trying to close the window. |
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|
|
| Pat.#5648787: |
Penetrating microwave
radar ground plane antenna |
| INVENTORS: |
Ogot; Rolando B.,
San Diego, CA |
| |
Gaspar; Mark, Glendale,
CA |
| ASSIGNEES: |
Patriot Scientific
Corporation, Poway, CA |
| ISSUED: |
July 15, 1997 |
| FILED: |
Nov. 29, 1994 |
| ABSTRACT:
A penetrating microwave radar ground plane antenna system
with separate arrays of transmission antenna elements and receiving antenna
elements. The lengths of transmitting and receiving antenna elements are
selected to enable the transmission of a nearly single-cycle pulse, the
reduction of ringing between antenna elements, the reception of a signal
significantly reduced in noise, and the penetration of materials having
varying dielectric constants. |
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|
|
| Pat.#5630216: |
Micropower RF transponder
with superregenerative receiver and RF receiver with sampling mixer |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
May 13, 1997 |
| FILED: |
Sep. 6, 1994 |
| ABSTRACT:
A micropower RF transdponder employs a novel adaptation of
the superregenerative receiver wherein the quench oscillator is external
to the regenerative transistor. The quench oscillator applies an exponentially
decaying waveform rather than the usual sinewave to achieve high sensitivity
at microampere current levels. Further improvements include circuit simplifications
for antenna coupling, extraction of the detected signal, and a low-voltage
bias configuration that allows operation with less than a 1-volt rail voltage.
The inventive transponder is expected to operate as long as the battery
shelf life. |
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|
|
| Pat.#5610907: |
Ultrafast time
hopping CDMA-RF communications: code-as-carrier, multichannel operation,
high data rate operation and data rate on demand |
| INVENTORS: |
Barrett; Terence W.,
Vienna, VA 22182 |
| ASSIGNEES: |
none |
| ISSUED: |
Mar. 11, 1997 |
| FILED: |
July 29, 1994 |
| ABSTRACT:
An ultrashort pulse time hopping code-division-multiple-access
(CDMA) RF communications system in the time-frequency domain comprises
a transmitter including a short duration pulse generator for generating
a short duration pulse in the picosecond to nanosecond range and a controller
for controlling the generator, code means connected to the controller for
varying the time position of each short pulse in frames of pulses in orthogonal
superframes of ultrafast time hopping code division multiple access format,
precise oscillator-clock for controlling such timing, encoding modems for
transforming intelligence into pulse position modulation form, antenna/amplifier
system. A homodyne receiver is provided for receiving and decoding the
coded broadcast signal, and one or more utilization devices are connected
to the homodyne receiver. Preferably, the codes are orthogonal codes with
the temporal coding of the sequence of ultrafast, ultrawideband pulses
constituting the carrier for transmission by the antenna system. The homodyne
receiver includes a bank of decoder/modems, an acquisition system/matched
filter for synchronizing to a superframe transmission, identifying coded
sequencers in the superframe and assigning the transmissions to a selected
decoder/modem on the basis of code recognition. The system is adapted for
multichannel operation and provides a high overall data rate in the 500
mbs range for maximum multichannel operation. |
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|
|
| Pat.#5610611: |
High accuracy electronic
material level sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Mar. 11, 1997 |
| FILED: |
Aug. 3, 1995 |
| ABSTRACT:
The High Accuracy Electronic Material Level Sensor (electronic
dipstick) is a sensor based on time domain reflectometry (TDR) of very
short electrical pulses. Pulses are propagated along a transmission line
or guide wire that is partially immersed in the material being measured;
a launcher plate is positioned at the beginning of the guide wire. Reflected
pulses are produced at the material interface due to the change in dielectric
constant. The time difference of the reflections at the launcher plate
and at the material interface are used to determine the material level.
Improved performance is obtained by the incorporation of: 1) a high accuracy
time base that is referenced to a quartz crystal, 2) an ultrawideband directional
sampler to allow operation without an interconnect cable between the electronics
module and the guide wire, 3) constant fraction discriminators (CFDs) that
allow accurate measurements regardless of material dielectric constants,
and reduce or eliminate errors induced by triple-transit or "ghost" reflections
on the interconnect cable. These improvements make the dipstick accurate
to better than 0.1%. |
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|
|
| Pat.#5609059: |
Electronic multi-purpose
material level sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Mar. 11, 1997 |
| FILED: |
Dec. 19, 1994 |
| ABSTRACT:
The present electronic multi-purpose material level sensor
is based on time domain reflectometry (TDR) of very short electrical pulses.
Pulses are propagated along a transmission line that is partially immersed
in a liquid, powder, or other substance such as grain in a silo. The time
difference of the reflections at the start of the transmission line and
the air/liquid interface are used to determine levels to better than 0.01
inch. The sensor is essentially independent of circuit element and temperature
variations, and can be mass produced at an extremely low price. The transmission
line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or
CPW, and may typically be a strip placed along the inside wall of a tank.
The reflected pulses also contain information about strata within the liquid
such as sludge-build-up at the bottom of an oil tank. |
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|
|
| Pat.#5602964: |
Automata networks
and methods for obtaining optimized dynamically reconfigurable computational
architectures and controls |
| ASSIGNEES: |
Autometric, Incorporated,
Alexandria, VA |
| INVENTORS: |
Barrett; Terence W.,
Vienna, VA |
| ISSUED: |
Feb. 11, 1997 |
| FILED: |
May 21, 1993 |
| ABSTRACT:
A
system for obtaining optimum performance and optimum graceful degradation
from Lie algebra descriptions of a spectrum of reconfigurable network architectures,
including, neural nets and cellular automata comprised of interconnected
nodes. The dynamic performance of the computational process is monitored
by continued extraction of Liapounov exponent indicators, reconfiguring
said reconfigurable network architecture when said indicators predict non-optimum
performance. The reconfigurable networks are reconfigured and compensatory
adjustments are made of signal sampling performance and operating system
performance of said reconfigurable network architecture, and the operating
system architecture is optimized to the computational task by reconfiguration
of nodal capabilities and degree of interconnectedness between nodes to
obtain any Lie algebra description architectural form between ideal neural
net with maximum interconnectedness and ideal cellular automata with maximum
nodal capability. |
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|
|
| Pat.#5594456: |
Gas tube RF antenna |
| INVENTORS: |
Norris; Elwood G.,
Poway, CA |
| |
O'Bryant; David W.,
Sandy, UT |
| ASSIGNEES: |
Patriot Scientific
Corporation, Poway, CA |
| ISSUED: |
Jan. 14, 1997 |
| FILED: |
Sep. 7 , 1994 |
| ABSTRACT:
An antenna device for transmitting a short pulse duration
signal of predetermined radio frequency that eliminates a trailing antenna
resonance signal. The device includes a gas filled tube; a voltage source
for developing an electrically conductive path along a length of the tube
corresponding to a resonant wavelength multiple of the predetermined radio
frequency; and a signal transmission source coupled to the tube for supplying
a radio frequency signal to the conductive path for antenna transmission.
A method for transmitting a short pulse signal without a trailing residual
signal is also provided. |
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|
|
| Pat.#5592177: |
Polarization-rotation
modulated, spread polarization-rotation,wide-bandwidth radio-wave communications
system |
| INVENTORS: |
Barrett; Terence W.,
Vienna, VA |
| ASSIGNEES: |
Autometric, Incorporated,
Alexandria, VA |
| ISSUED: |
Jan. 7, 1997 |
| FILED: |
June 11, 1993 |
| ABSTRACT:
A wide bandwidth radio wave communication system having a
dual feed pair of cross-polarized antennas having a common axis and being
at orthogonal angles to each other. A source of RF signals is coupled to
the antennas and a shifter device is between at least one of the pair of
cross-polarized antennas and the source of RF signals for modulating the
polarization of RF signals launched by the pair of cross-polarized antennas. |
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|
|
| Pat.#5589838: |
Short range radio
locator system |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Dec. 31, 1996 |
| FILED: |
Aug. 3, 1995 |
| ABSTRACT:
A radio location system comprises a wireless transmitter
that outputs two megahertz period bursts of two gigahertz radar carrier
signals. A receiver system determines the position of the transmitter by
the relative arrival of the radar bursts at several component receivers
set up to have a favorable geometry and each one having a known location.
One receiver provides a synchronizing gating pulse to itself and all the
other receivers to sample the ether for the radar pulse. The rate of the
synchronizing gating pulse is slightly offset from the rate of the radar
bursts themselves, so that each sample collects one finely-detailed piece
of information about the time-of-flight of the radar pulse to each receiver
each pulse period. Thousands of sequential pulse periods provide corresponding
thousand of pieces of information about the time-of-flight of the radar
pulse to each receiver, in expanded, not real time. Therefore the signal
processing can be done with relatively low-frequency, inexpensive components.
A conventional microcomputer is then used to find the position of the transmitter
by geometric triangulation based on the relative time-of-flight information. |
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|
|
| Pat.#5586145: |
Transmission of
electronic information by pulse position modulation utilizing low average
power |
| INVENTORS: |
Morgan; Harry C.,
Camarillo, CA 93010 |
| |
Boyd; William H.,
Newbury Park, CA 91320 |
| ASSIGNEES: |
none |
| ISSUED: |
Dec. 17, 1996 |
| FILED: |
Nov. 10, 1994 |
| ABSTRACT:
A method and apparatus are shown for generating and transmitting
very short and widely separated high frequency sine-wave pulses of electromagnetic
energy into space. A transistor, a charging capacitor, and an inductor
are coupled into a first series loop path to form a discharge circuit.
A bias voltage source, the same charging capacitor, and a charging resistor
are coupled into a second series loop path to form a recharging circuit.
The bias voltage source is selected to be capable of biasing the forward
conduction path of the transistor near its breakdown condition. An original
information signal is sampled upon each occurrence of a periodic reference
signal, and the transistor is then triggered into its breakdown or avalanche
mode. The starting times of successive transmitted pulses are modified
in accordance with a pulse position modulation protocol. |
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|
|
| Pat.#5581256: |
Range gated strip
proximity sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Dec. 3, 1996 |
| FILED: |
Jun. 6, 1995 |
| ABSTRACT:
A range gated strip proximity sensor uses one set of sensor
electronics and a distributed antenna or strip which extends along the
perimeter to be sensed. A micro-power RF transmitter is coupled to the
first end of the strip and transmits a sequence of RF pulses on the strip
to produce a sensor field along the strip. A receiver is coupled to the
second end of the strip, and generates a field reference signal in response
to the sequence of pulse on the line combined with received electromagnetic
energy from reflections in the field. The sensor signals comprise pulses
of radio frequency signals having a duration of less than 10 nanoseconds,
and a pulse repetition rate on the order of 1 to 10 MegaHertz or less.
The duration of the radio frequency pulses is adjusted to control the range
of the sensor. An RF detector feeds a filter capacitor in response to received
pulses on the strip line to produce a field reference signal representing
the average amplitude of the received pulses. When a received pulse is
mixed with a received echo, the mixing causes a fluctuation in the amplitude
of the field reference signal, providing a range-limited Doppler type signature
of a field disturbance. |
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|
|
| Pat.#5576627: |
Narrow field electromagnetic
sensor system and method |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Nov. 19, 1996 |
| FILED: |
Mar. 17, 1995 |
| ABSTRACT:
A narrow field electromagnetic sensor system and method of
sensing a characteristic of an object provide the capability to realize
a characteristic of an object such as density, thickness, or presence,
for any desired coordinate position on the object. One application is imaging.
The sensor can also be used as an obstruction detector or an electronic
trip wire with a narrow field without the disadvantages of impaired performance
when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter
for transmitting a sequence of electromagnetic signals in response to a
transmit timing signal, a receiver for sampling only the initial direct
RF path of the electromagnetic signal while excluding all other electromagnetic
signals in response to a receive timing signal, and a signal processor
for processing the sampled direct RF path electromagnetic signal and providing
an indication of the characteristic of an object. Usually, the electromagnetic
signal is a short RF burst and the obstruction must provide a substantially
complete eclipse of the direct RF path. By employing time-of- flight techniques,
a timing circuit controls the receiver to sample only the initial direct
RF path of the electromagnetic signal while not sampling indirect path
electromagnetic signals. The sensor system also incorporates circuitry
for ultra-wideband spread spectrum operation that reduces interference
to and from other RF services while allowing co-location of multiple electronic
sensors without the need for frequency assignments. |
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|
|
| Pat.#5573012: |
Body monitoring
and imaging apparatus and method |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Nov. 12, 1996 |
| FILED: |
Aug. 9, 1994 |
| ABSTRACT:
A non-acoustic pulse-echo radar monitor is employed in the
repetitive mode, whereby a large number of reflected pulses are averaged
to produce a voltage that modulates an audio oscillator to produce a tone
that corresponds to the heart motion. The antenna used in this monitor
generally comprises two flat copper foils, thus permitting the antenna
to be housed in a substantially flat housing. The monitor converts the
detected voltage to an audible signal with both amplitude modulation and
Doppler effect. It further uses a dual time constant to reduce the effect
of gross sensor-to-surface movement. The monitor detects the movement of
one or more internal body parts, such as the heart, lungs, arteries, and
vocal chords, and includes a pulse generator for simultaneously inputting
a sequence of pulses to a transmit path and a gating path. The pulses transmitted
along the transmit path drive an impulse generator and provide corresponding
transmit pulses that are applied to a transmit antenna. The gating path
includes a range delay generator which generates timed gating pulses. The
timed gating pulses cause the receive path to selectively conduct pulses
reflected from the body parts and received by a receive antenna. The monitor
output potential can be separated into a cardiac output indicative of the
physical movement of the heart, and a pulmonary output indicative of the
physical movement of the lung. |
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|
|
| Pat.#5563605: |
Precision digital
pulse phase generator |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Oct. 8, 1996 |
| FILED: |
Aug. 2, 1995 |
| ABSTRACT:
A timing generator comprises a crystal oscillator connected
to provide an output reference pulse. A resistor-capacitor combination
is connected to provide a variable-delay output pulse from an input connected
to the crystal oscillator. A phase monitor is connected to provide duty-cycle
representations of the reference and variable-delay output pulse phase.
An operational amplifier drives a control voltage to the resistor-capacitor
combination according to currents integrated from the phase monitor and
injected into summing junctions. A digital-to-analog converter injects
a control current into the summing junctions according to an input digital
control code. A servo equilibrium results that provides a phase delay of
the variable-delay output pulse to the output reference pulse that linearly
depends on the input digital control code. |
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|
|
| Pat.#5543799: |
Swept range gate
radar system for detection of nearby objects |
| INVENTORS: |
Heger; Charles
E., Saratoga, CA |
| ASSIGNEES: |
Zircon Corporation,
Campbell, CA |
| ISSUED: |
Aug. 6 , 1996 |
| FILED: |
Sep. 2 , 1994 |
| ABSTRACT:
A cost-effective ultra-wideband radar system capable of locating
nearby buried objects such as reinforcing steel rods, pipes, and other
objects buried in concrete, soil, behind walls, or in the air. A sequence
of ultra-wideband radar pulses are emitted without a carrier and the system
detects deflected pulse energy caused by the transmitted pulse whenever
encountering a change in the medium i.e. an air to metal change or concrete
to metal change. This reflected energy is detected and visually displayed.
The range gate delay is continuously varied, thus changing the distance
from the unit to where the reflected energy would be potentially detected
from the target. By continuously sweeping the "depth" of the scan, the
operator need only move the unit in two dimensions across the surface to
detect objects buried or hidden at varying depths interior to or behind
the surface. The range gate system includes a multipoint ackground subtraction,
corrected gain with distance, linear range gate time correction and a dielectric
constant correction for a calibrated distance display. |
| Back
To Top |
|
|
| Pat.#5523760: |
Ultra-wideband
receiver |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Jun. 4, 1996 |
| FILED: |
Sep. 6, 1994 |
| ABSTRACT:
An ultra-wideband (UWB) receiver utilizes a strobed input
line with a sampler connected to an amplifier. In a differential configuration,
±UWB inputs are connected to separate antennas or to two halves
of a dipole antenna. The two input lines include samplers which are commonly
strobed by a gating pulse with a very low duty cycle. In a single ended
configuration, only a single strobed input line and sampler is utilized.
The samplers integrate, or average, up to 10,000 pulses to achieve high
sensitivity and good rejection of uncorrelated signals. |
| Back
To Top |
|
|
| Pat.#5523758: |
Sliding correlator
for nanosecond pulses |
| INVENTORS: |
Harmuth; Henning F.,
Potomac, MD |
| ASSIGNEES: |
Geophysical Survey
Systems, Inc., North Salem, NH |
| ISSUED: |
Jun. 4, 1996 |
| FILED: |
Jan. 25, 1990 |
| ABSTRACT:
A digital sliding correlator having means for producing a
series of time-shifted stored copies of a digital character, means responsive
to said shifted, stored copies of the character for multiplying said shifted,
stored copies by the input signal or the sign-inverted counterpart of the
input signal, a first set of integrators and a second set of integrators,
means for supplying to the first set of integrators first portions of said
multiplied signals and for supplying to said second set of integrators
second portions of said multiplied signals, and means for combining the
outputs of said integrators. |
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To Top |
|
|
| Pat.#5521600: |
Range-gated field
disturbance sensor with range-sensitivity compensation |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
May. 28, 1996 |
| FILED: |
Sep. 6, 1994 |
| 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 pseudorandomly modulated so that bursts
in the sequence of bursts have a phase which varies. |
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|
|
| Pat.#5519400: |
Phase coded, micro-power
impulse radar motion sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
May. 21, 1996 |
| FILED: |
Jun. 6, 1995 |
| ABSTRACT:
A
motion sensing, micro-power impulse radar MIR impresses on the transmitted
signal, or the received pulse timing signal, one or more frequencies lower
than the pulse repetition frequency, that become intermediate frequencies
in a "IF homodyne" receiver. Thus, many advantages of classical RF receivers
can be thereby be realized with ultra-wide band radar. The sensor includes
a transmitter which transmits a sequence of electromagnetic pulses in response
to a transmit timing signal at a nominal pulse repetition frequency. A
receiver samples echoes of the sequence of electromagnetic pulses from
objects within the field with controlled timing, in response to a receive
timing signal, and generates a sample signal in response to the samples.
A timing circuit supplies the transmit timing signal to the transmitter
and supplies the receive timing signal to the receiver. The relative timing
of the transmit timing signal and the receive timing signal is modulated
between a first relative delay and a second relative delay at an intermediate
frequency, causing the receiver to sample the echoes such that the time
between transmissions of pulses in the sequence and samples by the receiver
is modulated at the intermediate frequency. Modulation may be executed
by modulating the pulse repetition frequency which drives the transmitter,
by modulating the delay circuitry which controls the relative timing of
the sample strobe, or by modulating amplitude of the transmitted pulses.
The electromagnetic pulses will have a nominal center frequency related
to pulse width, and the first relative delay and the second relative delay
between which the timing signals are modulated, differ by less than the
nominal pulse width, and preferably by about one-quarter wavelength at
the nominal center frequency of the transmitted pulses. |
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|
|
| Pat.#5519342: |
Transient digitizer
with displacement current samplers |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
May. 21, 1996 |
| FILED: |
May. 11, 1994 |
| ABSTRACT:
A low component count, high speed sample gate, and digitizer
architecture using the sample gates is based on use of a signal transmission
line, a strobe transmission line and a plurality of sample gates connected
to the sample transmission line at a plurality of positions. The sample
gates include a strobe pickoff structure near the strobe transmission line
which generates a charge displacement current in response to propagation
of the strobe signal on the strobe transmission line sufficient to trigger
the sample gate. The sample gate comprises a two-diode sampling bridge
and is connected to a meandered signal transmission line at one end and
to a charge-holding cap at the other. The common cathodes are reverse biased.
A voltage step is propagated down the strobe transmission line. As the
step propagates past a capacitive pickoff, displacement current i=c(dv/dT),
flows into the cathodes, driving the bridge into conduction and thereby
charging the charge-holding capacitor to a value related to the signal.
A charge amplifier converts the charge on the charge-holding capacitor
to an output voltage. The sampler is mounted on a printed circuit board,
and the sample transmission line and strobe transmission line comprise
coplanar microstrips formed on a surface of the substrate. Also, the strobe
pickoff structure may comprise a planar pad adjacent the strobe transmission
line on the printed circuit board. |
| Back
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|
|
| Pat.#5517198: |
Ultra-wideband
directional sampler |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
May. 14, 1996 |
| FILED: |
Aug. 3, 1995 |
| ABSTRACT:
The Ultra-Wideband (UWB) Directional Sampler is a four port
device that combines the function of a directional coupler with a high
speed sampler. Two of the four ports operate at a high sub-nanosecond speed,
in "real time", and the other two ports operate at a slow millisecond-speed,
in "equivalent time". A signal flowing inbound to either of the high speed
ports is sampled and coupled, in equivalent time, to the adjacent equivalent
time port while being isolated from the opposite equivalent time port.
A primary application is for a time domain reflectometry (TDR) situation
where the reflected pulse returns while the outbound pulse is still being
transmitted, such as when the reflecting discontinuity is very close to
the TDR apparatus. |
| Back
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|
|
| Pat.#5512834: |
Homodyne impulse
radar hidden object locator |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Apr. 30, 1996 |
| FILED: |
Sep. 13, 1994 |
| 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 homodyneoscillator 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. |
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|
|
| Pat.#5510800: |
Time-of-flight
radio location system |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Apr. 23, 1996 |
| FILED: |
Sep. 6, 1994 |
| ABSTRACT:
A bi-static radar configuration measures the direct time-of-flight
of a transmitted RF pulse and is capable of measuring this time-of-flight
with a jitter on the order of about one pico-second, or about 0.01 inch
of free space distance for an electromagnetic pulse over a range of about
one to ten feet. A transmitter transmits a sequence of electromagnetic
pulses in response to a transmit timing signal, and a receiver samples
the sequence of electromagnetic pulses with controlled timing in response
to a receive timing signal, and generates a sample signal in response to
the samples. A timing circuit supplies the transmit timing signal to the
transmitter and supplies the receive timing signal to the receiver. The
receive timing signal causes the receiver to sample the sequence of electromagnetic
pulses such that the time between transmission of pulses in the sequence
and sampling by the receiver sweeps over a range of delays. The receive
timing signal sweeps over the range of delays in a sweep cycle such that
pulses in the sequence are sampled at the pulse repetition rate, and with
different delays in the range of delays to produce a sample signal representing
magnitude of a received pulse in equivalent time. Automatic gain control
circuitry in the receiver controls the magnitude of the equivalent time
sample signal. A signal processor analyzes the sample signal to indicate
the time-of-flight of the electromagnetic pulses in the sequence. |
| Back
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|
|
| Pat.#5493691: |
Oscillator-shuttle-circuit
(OSC) networks for conditioning energy in higher-order symmetry algebraic
topological forms and RF phase conjugation |
| INVENTORS: |
Barrett; Terence W.,
Vienna, VA 22182 |
| ASSIGNEES: |
none |
| ISSUED: |
Feb. 20, 1996 |
| FILED: |
Dec. 23, 1993 |
| ABSTRACT:
The present invention provides passive networks which act
as the host to nonlinear and parametric interactions, with energy inputs
to said networks being caused to "bleed off" auxiliary, and time-delayed
conditioning flows resulting in phase modulations to the main input and
which achieve, e.g., RF phase conjugation with cancellation of the noise
modulation after two-way passage of beams between transmitter and receiver
and when used in duplex arrangements. Also, passive networks for noise
reduction in communications transmission due to conditioning of electromagnetic
fields in higher order group symmetry form. Because atransmitted wave from
a network of the present invention is in higher-order group symmetry form,
and fields of such higher-order symmetry have a low probability of occurrence
naturally, then environmental noise, which is of lower group symmetry form
(usually, U(1) symmetry) and has a high probably of natural occurrence,
will be excluded from a receiver matched to higher-order symmetry waves.
Therefore in the case of communications, less noise will be processed statistically
at a receiver designed for SU(2) or higher group symmetry operation, resulting
in enhanced signal-to-noise. Also disclosed are passive networks for power
transmission resulting in decreased loss in transmission. Higher-order
group symmetry matched "receivers" will have enhanced signal-to-noise reception
over lower-order symmetry receivers, i.e., leakage to ground will be less. |
| Back
To Top |
|
|
| Pat.#5486833: |
Active signalling
systems |
| INVENTORS: |
Barrett; Terence W.,
Vienna, VA 22182 |
| ASSIGNEES: |
none |
| ISSUED: |
Jan. 23, 1996 |
| FILED: |
Apr. 2, 1993 |
| ABSTRACT:
A signalling system in time-frequency space for detecting
targets in the presence of clutter and for penetrating media, includes
a transmitter antenna system, receiver and processor system. The transmitter
antenna system generates and launches into a medium containing the targets
an energy pulse (wave packet) having a predetermined duration and frequency
characteristic, and which energy pulse matches at least one of the following:
1) the time-frequency reflection characteristics of the target(s) but not
the clutter, or 2) the penetration time-frequency dielectric window of
the medium, or 3) the time-frequency characteristics of the window of the
receiver. Preferably, the time-frequency wave packet is the complex conjugate
of the impulse response of the combined medium and target. Theprocessor
solves the wave equation for transmissions through the medium, reflectance
from the target(s) and transmission back through the medium and causes
a match of the generated wave packet signals to both the medium and target
for maximum propagation through the medium and reflectance from the target,
the wave packet match to the medium and the target being with respect to
both time and frequency response characteristics. |
| Back
To Top |
|
|
| Pat.#5479120: |
High speed sampler
and demultiplexer |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Dec. 26, 1995 |
| FILED: |
May. 11, 1994 |
| ABSTRACT:
A high speed sampling demultiplexer based on a plurality
of sampler banks, each bank comprising a sample transmission line for transmitting
an input signal, a strobe transmission line for transmitting a strobe signal,
and a plurality of sampling gates at respective positions along the sample
transmission line for sampling the input signal in response to the strobe
signal. Strobe control circuitry is coupled to the plurality of banks,
and supplies a sequence of bank strobe signals to the strobe transmission
lines in each of the plurality of banks, and includes circuits for controlling
the timing of the bank strobe signals among the banks of samplers. Input
circuitry is included for supplying the input signal to be sampled to the
plurality of sample transmission lines in the respective banks. The strobe
control circuitry can repetitively strobe the plurality of banks of samplers
such that the banks of samplers are cycled to create a long sample length.
Second tier demultiplexing circuitry is coupled to each of the samplers
in the plurality of banks. The second tier demultiplexing circuitry senses
the sample taken by the corresponding sampler each time the bank in which
the sampler is found is strobed. A plurality of such samples can be stored
by the second tier demultiplexing circuitry for later processing. Repetitive
sampling with the high speed transient sampler induces an effect known
as "strobe kickout". The sample transmission lines include structures which
reduce strobe kickout to acceptable levels, generally 60 dB below the signal,
by absorbing the kickout pulses before the next sampling repetition. |
| Back
To Top |
|
|
| Pat.#5471162: |
High
speed transient sampler |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Nov. 28, 1995 |
| FILED: |
Sep. 8, 1992 |
| ABSTRACT:
A high speed sampler comprises a meandered sample transmission
line for transmitting an input signal, a straight strobe transmission line
for transmitting a strobe signal, and a plurality of sampling gates along
the transmission lines. The sampling gates comprise a four terminal diode
bridge having a first strobe resistor connected from a first terminal of
the bridge to the positive strobe line, a second strobe resistor coupled
from the third terminal of the bridge to the negative strobe line, a tap
connected to the second terminal of the bridge and to the sample transmission
line, and a sample holding capacitor connected to the fourth terminal of
the bridge. The resistance of the first and second strobe resistors is
much higher than the signal transmission line impedance in the preferred
system. This results in a sampling gate which applies a very small load
on the sample transmission line and on the strobe generator. The sampleholding
capacitor is implemented using a smaller capacitor and a larger capacitor
isolated from the smaller capacitor by resistance. The high speed sampler
of the present invention is also characterized by other optimizations,
including transmission line tap ompensation, stepped impedance strobe line,
a multi-layer physical layout, and unique strobe generator design. A plurality
of banks of such samplers are controlled for concatenated or interleaved
sample intervals to achieve long sample lengths or short sample spacing. |
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|
|
| Pat.#5465094: |
Two terminal micropower
radar sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Nov. 7, 1995 |
| FILED: |
Jan. 14, 1994 |
| ABSTRACT:
A simple, low power ultra-wideband radar motion sensor/switch
configuration connects a power source and load to ground. The switch is
connected to and controlled by the signal output of a radar motion sensor.
The power input of the motion sensor is connected to the load through a
diode which conducts power to the motion sensor when the switch is open.
A storage capacitor or rechargeable battery is connected to the power input
of the motion sensor. The storage capacitor or battery is charged when
the switch is open and powers the motion sensor when the switch is closed.
The motion sensor and switch are connected between the same two terminals
between the source/load and ground. |
| Back
To Top |
|
|
| Pat.#5457394: |
Impulse radar studfinder |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Oct. 10, 1995 |
| FILED: |
May. 7, 1993 |
| ABSTRACT:
An impulse radar studfinder propagates electromagnetic pulses
and detects reflected pulses from a fixed range. Unmodulated pulses, about
200 ps wide, are emitted. A large number of reflected pulses are sampled
and averaged. Background reflections are subtracted. Reflections from wall
studs or other hidden objects are detected and displayed using light emitting
diodes. |
| Back
To Top |
|
|
| Pat.#5455593: |
Efficiently decreasing
the bandwidth and increasing the radiated energy of an UWB radar or data
link transmission |
| INVENTORS: |
Ross; Gerald F., Longboat
Key, FL |
| ASSIGNEES: |
Anro Engineering,
Inc., Lexington, MA |
| ISSUED: |
Oct. 3, 1995 |
| FILED: |
Jul. 18, 1994 |
| ABSTRACT:
An Ultra-Wideband (UWB) transmitter array consists of N individual
transmitters coupled to a reference cw oscillator. Each of the N transmitters
generates a waveform consisting of a number of cycles of a nominal carrier
frequency of f0. The duration of the amplitude spectrum of the envelope
of each signal is T. The transmitters are arranged in close proximity to
form a multipole moment and are precisely synchronized to each other and
delayed appropriately so that the resulting amplitude spectrum of the envelope
of the transmitter array is due to a pulse duration of NT seconds. This
reduces the overall signal bandwidth by a factor of N, at the same time
increasing the radiated energy by a factor of N. |
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|
|
| Pat.#5422607: |
Linear phase compressive
filter |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Jun. 6, 1995 |
| FILED: |
Feb. 9, 1994 |
| ABSTRACT:
A phase linear filter for soliton suppression is in the form
of a laddered series of stages of non-commensurate low pass filters with
each low pass filter having a series coupled inductance (L) and a reverse
biased, voltage dependent varactor diode, to ground which acts as a variable
capacitance (C). L and C values are set to levels which correspond to a
linear or conventional phase linear filter. Inductance is mapped directly
from that of an equivalent nonlinear transmission line and capacitance
is mapped from the linear case using a large signal equivalent of a nonlinear
transmission line. |
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|
|
| Pat.
#5389939: |
Ultra wideband
phased array antenna |
| INVENTORS: |
Tang; Raymond, Fullerton,
CA |
| |
Lee; Kuan M., Brea,
CA |
| ASSIGNEES: |
Hughes Aircraft Company,
Los Angeles, CA |
| ISSUED: |
Feb. 14, 1995 |
| FILED: |
Mar. 31, 1993 |
| ABSTRACT:
An ultra wideband (UWB) phased array antenna using a frequency-multiplexing,
space-fed lens with a UWB feed horn achieves multi-octave bandwidth. The
lens includes two UWB radiating apertures with relatively narrow band phase
shifters connecting corresponding radiating elements of the arrays. Each
aperture multiplexes the incoming UWB signal into separate frequency bands
so that the phase shifters need only be tuned to these narrower frequency
bands, and are set to form a beam in the desired direction. For wide instantaneous
bandwidth operation, the beams from the various frequency bands are collimated
in the same direction. For multi-mode operation, the beams corresponding
to the various frequency bands are formed in different directions. The
phase shifters need have a maximum phase shift of 360 degrees. |
| Back
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|
|
| Pat.
#5381151: |
Signal processing
for ultra-wideband impulse radar |
| INVENTORS: |
Boles; Sol, Syosset,
NY |
| |
Buckland; Dennis J.,
Bethpage, NY |
| ASSIGNEES: |
Grumman Aerospace
Corporation, Bethpage, NY |
| ISSUED: |
Jan. 10, 1995 |
| FILED: |
Feb. 2 , 1994 |
| ABSTRACT:
An ultra-wideband impulse radar system for use on an airborne
platform includes circuitry for coherently integrating the signals to improve
signal-to-noise ratio so as to enhance the detection capability of the
system, and for motion compensation of the signals to correct for inadvertent
modulations of received signals due to buffeting or vibration of the airborne
platform which may otherwise corrupt the filtering and signal integration
processes. The inclusion of velocity filters and coherent integration despite
the lack of phase information in the signals is accomplished by exploiting
the time-delay properties of the received impulse signals, in which the
observable pulse repetition frequency of the received signals differs from
the transmitted pulse repetition frequency by virtue of the relative velocity
between signal reflecting elements and the radar platform. |
| Back
To Top |
|
|
| Pat.
#5365240: |
Efficient driving
circuit for large-current radiator |
| INVENTORS: |
Harmuth; Henning F.,
Potomac, MD |
| ASSIGNEES: |
Geophysical Survey
Systems, Inc., North Salem, NH |
| ISSUED: |
Nov. 15, 1994 |
| FILED: |
Nov. 4, 1992 |
| ABSTRACT:
An improved driving circuit for a large-current radiator
avoids the need to dissipate large powers in the driving circuit by drawing
a certain energy value from a power supply to a storage capacitor and then
feeding this energy to the radiating antenna. A constant current source
provides, when a switching circuit coupled to the radiator is opened, a
current to counter the tendency of the radiator otherwise to maintain continuity
of current through the switching circuit, keeping to a minimum the voltage
across the switching circuit so that essentially no energy will need to
be dissipated in the driving circuit. By choosing the stored energy value
carefully one can make it just large enough to cover the radiated energy
but leave essentially no energy to be dissipated in the radiator driving
circuit. |
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|
|
| Pat.
#5363108: |
Time domain radio
transmission system |
| INVENTORS: |
Fullerton; Larry W.,
Huntsville, AL |
| ASSIGNEES: |
Phillips; Charles
A., Ardmore, TN |
| ISSUED: |
Nov. 8, 1994 |
| FILED: |
Mar. 5, 1992 |
| ABSTRACT:
A time domain communications system wherein a broadband of
time-spaced signals, essentially monocycle-like signals, are derived from
applying stepped-in-amplitude signals to a broadband antenna, in this case,
a reverse bicone antenna. When received, the thus transmitted signals are
multiplied by a D.C. replica of each transmitted signal, and thereafter,
they are, successively, short time and long time integrated to achieve
detection. |
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|
|
| Pat.
#5361070: |
Ultra-wideband
radar motion sensor |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
Regents of the University
of California, Oakland, CA |
| ISSUED: |
Nov. 1, 1994 |
| FILED: |
Apr. 12, 1993 |
| ABSTRACT:
A motion sensor is based on ultra-wideband (UWB) radar. UWB
radar range is determined by a pulse-echo interval. For motion detection,
the sensors operate by staring at a fixed range and then sensing any change
in the averaged radar reflectivity at that range. A sampling gate is opened
at a fixed delay after the emission of a transmit pulse. The resultant
sampling gate output is averaged over repeated pulses. Changes in the averaged
sampling gate output represent changes in the radar reflectivity at a particular
range, and thus motion. |
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|
|
| Pat.
#5351063: |
Ultra-wideband
high power photon triggered frequency independent radiator with equiangular
spiral antenna |
| INVENTORS: |
Kim; Anderson H.,
Toms River, NJ |
| |
DiDomenico; Leo D.,
Spotswood, NJ |
| |
Weiner; Maurice, Ocean,
NJ |
| |
Youmans; Robert J.,
Brick, NJ |
| |
Jasper, Jr.; Louis
J., Fulton, MD |
| ASSIGNEES: |
The United States
of America as represented by the Secretary of the Army, Washington, DC |
| ISSUED: |
Sep. 27, 1994 |
| FILED: |
May 19, 1993 |
| ABSTRACT:
A photoconductive switch coupled to an energy storage device
wherein the tch is comprised of photoconductive semiconductor material
while the energy storage device comprises two spiral metalized arms that
make up a spiral antenna. The photoconductive switch is electrically connected
to the storage device to facilitate fast discharge of the stored energy
through a load. A variation comprises a storage device comprising two separate
pieces of substrate material each having a spiral metalized arm. The separate
pieces being connected by highly dielectric material to form a spiral antenna
ultra wideband radiator. |
| Back
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|
|
| Pat.
#5351053: |
Ultra wideband
radar signal processor for electronically scanned arrays |
| INVENTORS: |
Wicks; Michael C.,
Utica, NY |
| |
Brown; Russell D.,
Holland Patent, NY |
| ASSIGNEES: |
The United States
of America as represented by the Secretary of the Air Force, Washington,
DC |
| ISSUED: |
Sep. 27, 1994 |
| FILED: |
July 30, 1993 |
| ABSTRACT:
A radar system that includes an ultra wideband radar signal
processor for electronically scanned arrays that utilizes frequency offset
generation (FOG) to achieve beam steering as compared with phase shift
an time delay techniques of conventional radars. The device comprises a
transmit antenna, a chirp generator connected to the transmit antenna and
a first summing circuit, a receiver antenna connected to the first summing
circuit, a Doppler de-ramping chirp circuit connected to a second summing
circuit, the output of the second summing circuit connected to an amplitude
and weighting circuit and the output of the amplitude circuit connected
to a spectrum analyzer of a Fast Fourier Transform (FFT) circuit. The signal
processing consists of mixing the target returns with the transmitted signal
to obtain a video beat note signal. This video beat note signal is mixed
with a Doppler de-ramping chirp waveform which is matched to the desired
target velocity. The output is amplitude weighted and the FFT algorithm
applied. To achieve beam steering for the detection of off boresight targets,
a phased array with distributed receivers is required. Also, frequency
offset generation must be incorporated into the Doppler de-ramping chirp
generator. |
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| Pat.
#5345471: |
Ultra-wideband
receiver |
| INVENTORS: |
McEwan; Thomas E.,
Livermore, CA |
| ASSIGNEES: |
The Regents of the
University of California, Oakland, CA |
| ISSUED: |
Sep. 6, 1994 |
| FILED: |
Apr. 12, 1993 |
| ABSTRACT:
An ultra-wideband (UWB) receiver utilizes a strobed input
line with a sampler connected to an amplifier. In a differential configuration,
±UWB inputs are connected to separate antennas or to two halves
of a dipole antenna. The two input lines include samplers which are commonly
strobed by a gating pulse with a very low duty cycle. In a single ended
configuration, only a single strobed input line and sampler is utilized.
The samplers integrate, or average, up to 10,000 pulses to achieve high
sensitivity and good rejection of uncorrelated signals. |
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