Patent EP1416291A2 successfully refreshed from Google Patents.
EP1416291A2
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EP
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Wideband NQR system using multiple de-coupled RF coils
Assignee: Analogic Corp
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Filing: 2003-10-30
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Granted: —
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Expires: 2023-10-30
Abstract
Abstract A wideband NQR detection system includes an RF coil system (110) having a plurality of RF coils that can be used to excite and detect a plurality of NQR spectral lines at the same time. Each of the plurality of RF coils is shaped and configured so as to generate, when driven by RF pulses, RF fields that are substantially de-coupled, for example by being mutually orthogonal. In this way, each coil can function independently, without affecting the operation of any other coil. The RF pulses used to excite NQR resonances can be prepared digitally, as a composite waveform formed as a superposition of individual waveforms, each optimally tailored to excite one spectral line. The wideband NQR detection system also includes a wideband transmitter (120) for generating and transmitting RF pulses, and a wideband receiver (130) for receiving the NQR response signals detected by the coils.
Inventors
- 👤 Ching-Ming-Lai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 02:25
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/441
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
117 words
An NQR (nuclear quadrupole resonance) system for detecting NQR spectral lines from an
object containing one or more quadrupolar nuclei, the system comprising: A. a transmitter for generating and transmitting RF signals; B. at least two RF coils shaped and configured to generate, when driven by said RF signals, RF
electromagnetic fields that are substantially de-coupled from each other, so that a plurality of nuclear
quadrupole resonances are excited when said de-coupled RF fields are applied to at least a portion of
said object at frequencies matching characteristic transition frequencies for said resonances, said RF
coils being operable to detect NQR response signals from said object; and C. a receiver for receiving said detected NQR response signals.
Claim 2
Dependent Claim
25 words
An NQR system according to claim 1, wherein said RF fields generated by said at least two
RF coils. are substantially orthogonal to each other.
Claim 3
Dependent Claim
32 words
An NQR system according to claim 1, wherein each RF coil is tuned to at least one
resonant frequency substantially marching a characteristic spectral frequency of one of said NQR
spectral lines.
Claim 4
Dependent Claim
58 words
An NQR system according to claim 1, wherein each RF coil is multiply tuned to a
plurality of resonant frequencies for concurrent detection by said coil of a plurality of NQR
spectral lines, and wherein said plurality of resonant frequencies for a given RF coil correspond
to characteristic spectral frequencies of respective ones of said NQR spectral lines.
Claim 5
Dependent Claim
29 words
An NQR system according to claim 4, wherein at least one resonant frequency of a given
RF coil is relatively close to a resonant frequency of another RF coil.
Claim 6
Dependent Claim
15 words
An NQR system according to claim 1, wherein said RF signals comprise pulsed RF
signals.
Claim 7
Dependent Claim
48 words
An NQR system according to claim 6, wherein each pulsed RF signal comprises a
composite waveform formed as a superposition of a plurality of individual waveforms, each
individual waveform being characterized by a frequency that substantially matches a
characteristic spectral frequency of one of said NQR spectral lines.
Claim 8
Dependent Claim
33 words
An NQR system according to claim 1, wherein said object includes one or more chemical
compounds, and wherein said chemical compounds include at least one of TNT, RDX, HMX,
PETN, cocaine, and heroine.
Claim 9
Dependent Claim
32 words
An NQR system according claim 1, wherein each RF coil is operable both to excite at
least one nuclear quadrupole resonance, and to detect the NQR response signal resulting from
said resonance.
Claim 10
Dependent Claim
24 words
An NQR system in accordance with claim 1, wherein said transmitter comprises a power
amplifier for driving said RF coils with said RF signals.
Claim 11
Dependent Claim
23 words
An NQR system in accordance with claim 1, wherein said transmitter comprises a wideband
transmitter, and wherein said receiver comprises a wideband receiver.
Claim 12
Dependent Claim
36 words
An NQR system in accordance with claim 1, wherein said at least two RF coils are
constructed and arranged so as to define a hollow interior region having a size sufficient to enclose
said object therewithin.
Claim 13
Dependent Claim
28 words
A wideband NQR system according to claim 1, wherein said object forms part of a structure
comprising at least one of a package item, and a luggage item.
Claim 14
Dependent Claim
29 words
An NQR system according to claim 4, wherein at least one resonant frequency of a given RF
coil is substantially identical to a resonant frequency of another RF coil.
Claim 15
Dependent Claim
128 words
An NQR system for simultaneously detecting a plurality of NQR spectral lines, the system
comprising: A. means for generating pulsed RF signals; B. three RF coils shaped and configured so as to generate, when driven by said RF signals,
substantially orthogonal and de-coupled RF electromagnetic fields in the x, y, and z directions,
respectively; wherein upon transmission of said orthogonal RF electromagnetic fields by said RF coils onto a
given region of an obj ect containing quadrupolar nuclei, a plurality of nuclear quadrupole resonances
can be concurrently excited in said region, and wherein said three RF coils are operable to detect from said object the NQR response signals
resulting from said plurality of excited resonances; and C. means for receiving said NQR response signals from said RF coils.
Claim 16
Dependent Claim
144 words
A wideband NQR system for simultaneously detecting multiple NQR resonance frequencies,
the system including: A. means for generating pulsed RF signals; B. at least a first set of RF coils and a second set of RF coils, wherein each set of coils
comprises: a plurality of RF coils shaped and configured to generate, when driven by said RF signals,
RF electromagnetic fields that are mutually orthogonal and substantially de-coupled, so that a
plurality of nuclear quadrupole resonances can be excited simultaneously by applying said mutually
orthogonal RF fields to at least a portion of an object containing quadrupolar nuclei, each RF coil
being operable both to excite nuclear quadrupole resonances, and to detect the NQR response signals
resulting from said excited resonances; and C. means for receiving respective NQR response signals from each of said plurality of RF coils
in each set of coils.
Claim 17
Dependent Claim
150 words
A wideband NQR system for simultaneously detecting multiple nuclear quadrupole spectral
lines, the system comprising: A. a wideband transmitter for generating and transmitting pulsed RF signals; B. a plurality of RF coils that are shaped and configured to generate, when driven by said RF
signals, oscillating RF electromagnetic fields that are substantially de-coupled from each other, so
that a plurality of nuclear quadrupole resonances can be excited simultaneously by applying said de-coupled
RF fields to at least a portion of an object containing quadrupolar nuclei, at frequencies
matching characteristic transition frequencies for said resonances, said RF coils also functioning as
pickup coils for detecting the NQRresponse signals resulting from said excited resonances, each RF
coil being tuned to a plurality of resonant frequencies corresponding to the characteristic spectral
frequencies of respective ones of said resonances; and C. a wideband receiver for receiving from said RF coils said NQR response signals.
Claim 18
Dependent Claim
109 words
A wideband NQR system according to claim 17, wherein said wideband transmitter
comprises: a. pulse generating means for generating a sequence of RF pulses, wherein each RF pulse is a composite waveform formed as a superposition of a plurality of
individual waveforms, each individual waveform being characterized by a different frequency; and wherein at least one of said plurality of individual waveforms is amplitude-modulated and scaled for
excitation of an NQR spectral line at one of said tuned resonant frequencies of one of said RF coils;
and b. at least one wideband power amplifier for driving said RF coils with said RF pulses
generated by said pulse generating means.
Claim 19
Dependent Claim
29 words
A wideband NQR system according to claim 18, wherein said pulse generating means
comprises a digital waveform generator for digitally computing said composite waveforms and the
constituent individual waveforms.
Claim 20
Dependent Claim
49 words
A wideband NQR system according to claim 18, wherein one or more of said RF pulses is a
combination of a plurality of said composite waveforms, each of said plurality of composite
waveforms differing from each other in at least one of starting phase, pulse width, and amplitude
modulation.
Claim 21
Dependent Claim
35 words
An NQR system according to claim 18, wherein each composite waveform comprises at least
one of: 1) a waveform generated in real time; and 2) a waveform read out from a table of pre-computed
waveforms.
Claim 22
Dependent Claim
22 words
A wideband NQR system according to claim 18, wherein said plurality of RF coils are
driven by a single wideband power amplifier.
Claim 23
Dependent Claim
125 words
A wideband NQR system according to claim 17, wherein said wideband receiver comprises: A. a receiver channel for each RF coil, each receiver channel including: i. a wideband preamplifier, said wideband preamplifier having an input for receiving one or
more NQR signals from each RF coil, and an output for providing an output RF signal; ii. a wideband filter for filtering said output RF signal from said wideband preamplifier, so as to
provide a filtered RF signal; and iii. a digitizer for digitizing said filtered RF signal so as to provide one or more digitized output
signals from each receiver channel;
and B. a digital processor for processing the digitized output signals from each receiver channel, so
as to extract therefrom NQR spectral line information.
Claim 24
Dependent Claim
28 words
A wideband NQR system according to claim 23, wherein said digitizer is adapted to digitize
said filtered RF signal without downshifting the frequency of said filtered RF signal.
Claim 25
Dependent Claim
50 words
A wideband NQR system according to claim 23, wherein said digital processor is adapted to
average said digitized output signals in accordance with said sequence of RF pulses, and wherein
said digital processor is further adapted to Fourier transform said digitized output signals so as to
generate NQR spectral lines.
References Cited (Backward Citations)
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