U.S. patent number RE37,561 [Application Number 09/219,150] was granted by the patent office on 2002-02-26 for rf signal train generator and interferoceivers.
Invention is credited to Ming-Chiang Li.
United States Patent |
RE37,561 |
Li |
February 26, 2002 |
RF signal train generator and interferoceivers
Abstract
New apparatus .[.comprise a.]. .Iadd.comprises an
.Iaddend.optical fiber based RF signal train generator for storing
transient RF pulses and regenerating the identical replicas for
analysis. The apparatus further .[.comprise.]. .Iadd.comprises an
.Iaddend.RF .[.receivers.]. .Iadd.receiver .Iaddend.to process one
stored pulse with a reference to .[.other.]. .Iadd.another
.Iaddend.stored pulse. The present invention drastically increases
our abilities to investigate acoustical, electromagnetic, and
optical transient phenomena.
Inventors: |
Li; Ming-Chiang (Mitchellville,
MD) |
Family
ID: |
46276300 |
Appl.
No.: |
09/219,150 |
Filed: |
December 12, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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018388 |
Feb 17, 1993 |
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185177 |
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877419 |
May 1, 1992 |
5294930 |
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185177 |
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787085 |
Nov 4, 1991 |
5296860 |
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Reissue of: |
185177 |
Jan 24, 1994 |
05589929 |
Dec 31, 1996 |
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Current U.S.
Class: |
356/5.01;
342/172; 342/175; 367/127; 367/149 |
Current CPC
Class: |
G01S
7/495 (20130101); G01S 13/003 (20130101); G01S
13/87 (20130101); G01S 7/288 (20130101); G01S
7/4052 (20130101); G01S 7/282 (20130101); G01S
7/003 (20130101); G01S 13/86 (20130101); G01S
7/4091 (20210501) |
Current International
Class: |
G01S
7/48 (20060101); G01S 7/495 (20060101); G01S
7/288 (20060101); G01S 7/40 (20060101); G01S
7/285 (20060101); G01S 13/00 (20060101); G01S
13/87 (20060101); H04B 10/22 (20060101); H04K
3/00 (20060101); G01S 13/86 (20060101); G01S
7/00 (20060101); G01S 7/28 (20060101); G01S
7/282 (20060101); G01C 003/08 (); G01S 007/40 ();
G01S 013/00 (); G01S 003/80 () |
Field of
Search: |
;356/5.01,5.15,345,28.5
;342/172,175 ;367/127,149 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Buczinski; Stephen C.
Parent Case Text
This application is a continuation-in-part of application Ser. No.
18,388 filed Feb. 17, 1993.Iadd., which was refiled as Ser. No.
08/439,284 on May 11, 1995 now U.S. Pat. No. 5,955,983,
.Iaddend.and a continuation-in-part of Ser. No. 877,419 filed May
1, 1992 now U.S. Pat. No. 5,294,930 and a continuation-in-part of
Ser. No. 787,085 filed Nov. 4, 1991 now U.S. Pat. No. 5,296,860.
Claims
What is claimed is:
1. An interferoceiver comprising:
an input system for receiving one or more RF signals from a source
and for applying the one or more RF signals to an RF signal train
generator;
wherein the RF signal train generator comprises:
means, responsive to the input, for storing the one or more RF
signals;
means for regenerating replicas of the one or more stored RF
signals;
means for pairing the regenerated replicas; and
means for outputting the paired replicas.
2. The interferoceiver of claim 1 further comprising an RF
receiver; wherein the RF receiver comprises means for receiving the
replicas of the RF signals; and means for processing the replicas
with a reference to their pairs..[.
3. The interferoceiver of claim 2 wherein said source comprises
means for generating an acoustical signal and for splitting the
generated acoustical signal in parts; wherein the interferoceiver
further comprises means for sending one of parts to the RF signal
train generator; wherein the interferoceiver further comprises a
system under test, and means for sending other parts through the
system under test to the RF signal train generator; wherein the RF
signal train generator further comprises means for convening
acoustical signals to RF signals..]..[.
4. The interferoceiver of claim 2 wherein said source comprises
means for generating an acoustical signal; wherein the
interferoceiver further comprises a system under test, and means
for sending the acoustical signal to the system under test; wherein
the system under test comprises means for splitting the acoustical
signal into parts, and for sending split parts to the RF signal
train generator; wherein the RF signal train generator further
comprises means for converting acoustical signals to RF
signals..]..[.
5. The apparatus of claim 2 wherein said source comprises means for
generating an RF signal and for splitting the generated RF signal
in parts; wherein the interferoceiver further comprises means for
sending one of parts to the RF signal train generator; wherein the
interferoceiver further comprises a system under test, and means
for sending other parts through the system under test to the RF
signal train generator..]..[.
6. The interferoceiver of claim 2 wherein said source comprises
means for generating an RF signal; wherein the interferoceiver
further comprises a system under test, and means for sending the RF
signal to the system under test; wherein the system under test
comprises means for splitting the RF signal into parts, and for
sending split pans to the RF signal train generator..]..[.
7. The interferoceiver of claim 2 wherein said source comprises
means for generating an optical signal and for splitting the
generated optical signal in parts; wherein the interferoceiver
further comprises means for sending one of parts to the RF signal
train generator; wherein the interferoceiver further comprises a
system under test, and means for sending other parts through the
system under test to the RF signal train generator; wherein the RF
signal train generator further comprises means for converting
optical signals to RF signals..]..[.
8. The interferoceiver of claim 2 wherein said source comprises
means for generating an optical signal; wherein the interferoceiver
further comprises a system under test, and means for sending the
optical signal to the system under test; wherein the system under
test comprises means for splitting the optical signal into parts,
and for sending split parts to the RF signal train generator;
wherein the RF signal train generator further comprises means for
converting optical signals to RF signals..].
9. A method for operating an interferoceiver comprising steps
of:
(a) storing one or more RF signals from a source in an RF signal
train generator;
(b) regenerating replicas of the one or more stored RF signals from
the RF signal train generator; and
(c) pairing the regenerated replicas.
10. The method of claim 9 further comprising steps of:
(d) processing the replicas in a reference to their pairs. .[.
11. The method of claim 10 further comprising steps of:
(e) generating an acoustical signal from the source;
(f) splitting the acoustical signal into parts;
(g) sending one of part to the RF signal train generator and send
other parts through a system under test to the RF signal train
generator; and
(h) converting acoustical signals to RF signals..]. .[.
12. The method of claim 10 further comprising steps of:
(e) generating an acoustical signal from the source;
(f) sending the acoustical signal to a system under test;
(g) splitting the acoustical signal by the system under test and
sending the split acoustical signals to the RF signal train
generator; and
(h) convening acoustical signals to RF signals..]. .[.
13. The method of claim 10 further comprising steps of:
(e) generating an RF signal from the source;
(f) splitting the RF signal into pans; and
(g) sending one of part to the RF signal train generator and send
other parts through a system under test to the RF signal train
generator..]. .[.
14. The method of claim 10 further comprising steps of:
(e) generating an RF signal from the source;
(f) sending the RF signal to a system under test; and
(g) splitting the RF signal by the system under test and sending
the split RF signals to the RF signal train generator..]. .[.
15. The method of claim 10 further comprising steps of:
(e) generating an optical signal from the source;
(f) splitting the optical signal into parts;
(g) sending one of parts to the RF signal train generator and send
other parts through a system under test to the RF signal train
generator; and
(h) converting optical signals to RF signals..]. .[.
16. The method of claim 10 further comprising steps of:
(e) generating an optical signal from the source;
(f) sending the optical signal to a system under test;
(g) splitting the optical signal by the system under test and
sending the split acoustical signals to the RF signal train
generator; and
(h) converting optical signals to RF signals..].
17. An apparatus for investigating transient phenomena
comprising:
an input system for receiving an RF pulse from a source and for
applying the RF pulse to an RF signal train generator;
wherein the RF Signal train generator comprises:
means, responsive to the input, for storing the RF pulse;
means for regenerating a train of replicas from the stored RF
pulse; and
means for sampling regenerated replicas in the train with different
delays. .[.
18. The apparatus of claim 17 wherein said source is an optical,
infrared electromagnetic, mechanical or acoustical
source..]..[.
19. The apparatus of claim 17 wherein said RF signal train
generator further comprises: means for receiving a second pulse
from the source and for generating the replicas of the second
pulse;
wherein the apparatus further comprises means for processing the
replicas of the first pulse with a reference to the replicas of the
second pulse..]. .[.
20. The apparatus of claim 17 further comprises means for
processing the replicas with an RF receiver..]..Iadd.
21. An interferoceiver comprising:
an input system which receives one or more signals and outputs RF
signals;
an RF signal train generator which receives the RF signals from the
input system and outputs multiple paired replicas of the RF
signals. .Iaddend..Iadd.
22. The interferoceiver of claim 21 further comprising an RF
receiver, which pairwise analyzes the paired replicas of the RF
signals. .Iaddend..Iadd.
23. The interferoceiver of claim 22 further comprising a source,
which emits the one or more signals. .Iaddend..Iadd.
24. The interferoceiver of claim 22 further comprising a
source;
wherein the source emits one or more signals;
wherein a splitter splits the one or more signals into a first
group of signals and a second group of signals;
wherein the second group of signals transits to, and interacts
with, a system; and
wherein the input system is adapted to receive the first group of
signals and the interacted second group of signals.
.Iaddend..Iadd.
25. The interferoceiver of claim 22 further comprising a
source;
wherein the source emits one or more signals which interact with a
system; and
wherein the input system is adapted to receive the interacted one
or more signals. .Iaddend..Iadd.
26. The interferoceiver of claim 21;
wherein the input system comprises a splitter which splits the one
or more signals. .Iaddend..Iadd.
27. The interferoceiver of claim 21;
wherein the RF signal train generator comprises a pairing apparatus
which pairs the generated replicas. .Iaddend..Iadd.
28. The interferoceiver of claim 21;
wherein the RF signal train generator comprises an optical store
which stores the RF signals as optical RF signals.
.Iaddend..Iadd.
29. The interferoceiver of claim 28;
wherein the RF signal train generator comprises an extractor which
generates replicas of the optical RF signals stored in the optical
store. .Iaddend..Iadd.
30. The interferoceiver of claim 29;
wherein the optical store and the extractor are configured so that
the replicas generated by the extractor are paired.
.Iaddend..Iadd.
31. The interferoceiver of claim 28;
wherein the optical store comprises one or more optical RF delay
loops, or comprises one delay lines. .Iaddend..Iadd.
32. The interferoceiver of claim 22;
wherein the RF receiver comprises a digitizer which analyzes the
paired replicas of the RF signals by using one of the paired
replicas as triggering pulses to sample another one of the paired
replicas. .Iaddend..Iadd.
33. The interferoceiver of claim 32;
wherein the digitizer further comprises a delay apparatus which
systematically delays the triggering pulses. .Iaddend..Iadd.
34. The interferoceiver of claim 22;
wherein the RF receiver comprises a coherent receiver which
analyzes the paired replicas of the RF signals by using one of the
paired replicas as a reference to produce relative amplitudes and
phases or relative frequency differences between the RF signals.
.Iaddend..Iadd.
35. The interferoceiver of claim 21;
wherein the input system is adapted to receive at least one of
optical, infrared, acoustical, electromagnetic, mechanical, or
nuclear signals. .Iaddend..Iadd.
36. The apparatus of claim 21;
wherein the input system is adapted to output optical RF signals,
and the RF signal train generator is adapted to receive optical RF
signals. .Iaddend..Iadd.
37. A method for investigating one or more signals comprising steps
of:
receiving the one or more signals and outputting RF signals;
receiving the RF signals by an RF signal train generator; and
outputting multiple paired replicas of the RF signals.
.Iaddend..Iadd.
38. The method of claim 37 further comprising a step of:
pairwise analyzing the paired replicas. .Iaddend..Iadd.
39. The method of claim 38 further comprising a step of:
emitting the one or more signals from a source. .Iaddend..Iadd.
40. The method of claim 38 further comprising steps of:
splitting the one or more signals into a first group of signals and
a second group of signals;
interacting the second group with a system; and
wherein the step of receiving comprises steps of receiving the
first group of signals and the interacted second group of signals.
.Iaddend..Iadd.
41. The method of claim 38 further comprising a step of:
interacting the one or more signals with a system; and
wherein the step of receiving comprises a step of receiving the
interacted one or more signals. .Iaddend..Iadd.
42. An apparatus for investigating one or more signals
comprising:
an input system which receives the one or more signals and outputs
RF signals;
an RF signal train generator which receives the RF signals from the
input system and regenerates a train of replicas; and
a receiver which samples the regenerated replicas in the train with
different delays. .Iaddend..Iadd.
43. The apparatus of claim 42;
wherein the receiver further comprises a correlator.
.Iaddend..Iadd.
44. The apparatus of claim 42;
wherein the receiver is adapted to output a data stream, and to
send the data stream to a medium. .Iaddend..Iadd.
45. The apparatus of claim 42;
wherein the input system is adapted to output optical RF signals,
and the RF signal train generator is adapted to receive optical RF
signals. .Iaddend..Iadd.
46. A method for investigating one or more signals comprising steps
of:
receiving the one or more signals;
outputting one or more RF signals and regenerating a train of
replicas of the RF signals; and
sampling the regenerated replicas in the train with different
delays. .Iaddend..Iadd.
47. The method of claim 46 further comprising steps of:
producing a data stream; and
sending the data system to a medium. .Iaddend..Iadd.
48. The method of claim 46 further comprising a step of storing the
one or more signals as one or more optical RF signals. .Iaddend.
Description
TECHNICAL FIELD OF INVENTION
This invention relates to .Iadd.an .Iaddend.apparatus which
.[.utilize.]. .Iadd.utilizes .Iaddend.an optical fiber loop based
RF signal train generator to store transient pulses and regenerate
their identical replicas for analysis. The present invention
drastically increases our abilities to investigate acoustical,
electromagnetic, and optical transient phenomena.
BACKGROUND
Interferometer is a widely used instrument. The constituents of
interferometers may vary, but they all comprise these essential
elements: a source, a splitter, two paths, and a detection
apparatus. The source may generate acoustical, electromagnetic, and
light wave, which is split into two paths by the splitter. The
detection apparatus compares waves from the two paths, and
.[.determine.]. .Iadd.determines .Iaddend.their variational
differences. Interferometer is a powerful instrument, which is
capable of probing micro, meso, and macro systems. A system under
test may be the source, the splitter, or an external system
inserted into an interferometer path. We can infer the physical
characteristics of the system under test from the observed
variational differences.
An interferometer with a continuous wave source requires both the
interferometer and system under test to be stable and stationary.
Any random and vibrational motion will blur the variational
differences, and mask the physical characteristics of the system
under test. An interferometer with a short-pulsed source will
freeze a transient natural event. However, with a conventional
interferometer we are not able to decipher completely the
variational difference created by a single transient event.
Multiple pulses and events are needed, thus the short pulse and the
transient event have to be exactly and repeatedly reproduced. This
may not be possible with all transient events.
Digitizing receiver is another widely used instrument. It comprises
a radio frequency (RF) receiver and a digitizer. In a receiving
process, the RF receiver first converts an RF signal to an
intermediate frequency (IF) signal, and then to a video signal. A
digitizer converts the analog video signal to a digital signal. The
capability of a digitizer depends on its sampling rate. Digitizers
with sampling rate of 200 MHz are commercially available.
Digitizers with sampling rate of 1 GHz have been reported.
Depending on the capability of a digitizer, the down conversion to
a video signal may not be needed and a digitizer may directly
digitize .[.a.]. .Iadd.an .Iaddend.IF signal. A down conversion
will filter away many intrinsic traits of a transient event. Most
radar receivers have IF frequency of 60 MHz. More sophisticated RF
receivers have IF frequency of 10 GHz to preserve the intrinsic
traits of subnanosecond RF pulses. It is still impossible for a
digitizing receiver to completely capture the intrinsic traits of a
single RF pulse with frequency of 10 GHz and pulse width of 1 GHz.
Multiple pulses and events are again needed.
In light of the above, there is a need in the art for .Iadd.a
.Iaddend.new apparatus which .[.are.]. .Iadd.is .Iaddend.capable of
capturing the intrinsic traits of and determining the variational
differences created by a random, chaotic, turbulent, or transient
phenomenon. Furthermore it will reveal the physical traits of a
single transient event without instability blurring. An
interferoceiver with RF signal train generator will fulfill the
needs to capture transient traits and to overcome the blurring. The
physical principle for the new interferoceiver to capture .[.an.].
.Iadd.a .Iaddend.transient event is the same as that for optical
fiber based radars with an RF signal train generator.
THEORY OF INVENTION
The conventional method.[., which.]. rests on the available
technology. As the technology evolves, we are able to decipher a
single transient event completely. The technology is the optical
fiber RF delay loop based RF signal train generator. The
information concerns the delay loop and generator can be found in
the parent patent applications. With their help, a radar is able to
determine the range and Doppler shift of a target with a single
radar pulse. We will give a brief discussion here on the RF signal
train generation.
Let us assume the single input RF pulse to the loop has the
form
where .omega. is the circular frequency of the RF pulse with a
pulse profile A (t-t.sub.i) centered at the time t.sub.i.
Experimentally we can not decipher the intrinsic characteristics of
a short RF pulse. It is the limitation imposed by the sampling rate
and Nyquist theorem. RF pulses are transient. Media were not
available to record a transient RF: pulse faithfully for the
examination at a later time. Since the experimental means did not
exist for completely deciphering a short RF pulse, we had to rely
on the .[.alternative.]. .Iadd.alternate .Iaddend.methods. These
methods are only useful to those short RF pulses which can be
reproduced exactly by their respective sources. We then examine a
portion of each reproduced pulse. The information from the
reproduced pulses .[.are.]. .Iadd.is .Iaddend.aggregated to
complete the deciphering of a short RF pulse. A sample oscilloscope
uses such a method to decipher a short RF pulse.
Now the optical fiber RF delay loop provides an .[.alternative.].
.Iadd.alternate .Iaddend.method. The delay loop causes the pulse
delay of the input RF pulse. The pulse train emerged from the
optical fiber delay loop can be expressed as ##EQU1##
where N is the number of pulses in the train, .tau. the time delay
of the loop, and t.sub.i =i.times..tau. denotes the time delay of
.[.a.]. .Iadd.an .Iaddend.RF pulse emerged from the storage loop
after looping i times. The delay caused by an optical fiber is a
dynamical delay. RF pulse in the emerging train replicates the
input RF pulse. By examining the copies of its replicas, a short RF
pulse can be completely deciphered and repeatedly examined. It is
impossible with a conventional digitizing receiver or
interferometer.
A reference pulse is required in deciphering an RF pulse. It plays
two roles. These are the triggering in a digitizing receiver and
the referencing in an interferometer. The triggering instructs the
digitizer when to sample. The referencing provides an
interferometer with a basis in evaluating what a transient
phenomenon has affected the probing pulse. An additional optical
fiber RF delay loop has to be introduced in yielding a reference
pulse train. An RF signal train generator comprises two identical
optical fiber RF delay loops, which will fulfill the needs. We then
examine each copy of the RF pulse replicas with the help from a
copy of the reference pulse replicas.
Pulsed signals may be acoustical, electromagnetic, and optical.
These pulse signals in their respective receivers and
interferometers will be eventually converted to the electromagnetic
pulse signals. Hence, RF signal train generators can be coupled
with acoustical, electromagnetic, and optical signals to
investigate their respective phenomena.
SUMMARY OF THE INVENTION
Embodiments of the present invention, which has a board functional
capability, advantageously satisfy the above identified needs in
the art. Embodiments of the present invention will provide an
interferoceiver which is versatile and sophisticated. Such an
interferoceiver will capture the intrinsic characteristics of a
transient event without the blurring from its instability. In
particular, embodiments of the present invention comprise optical
fiber RF delay loops for storing short pulses, and reproducing
their identical replicas.
In preferred embodiments of the present invention, the
interferoceivers are equipped with an RF signal train generator,
digitizing and intra pulse coherent processing subsystems. As a
result, a new interferoceiver will be able to freeze a transient
event, and will have the functional capabilities of determining the
statistical distribution, which describes the instability of
random, chaotic, turbulent, and transient phenomena. As those of
ordinary skill in the art will readily appreciate, in the light of
intra pulse coherence, the instability blurring associated with
multiple pulses will no longer be a problem, and external
interferences from other sources will be drastically reduced.
In other embodiments of the present invention, the RF signal train
generator, digitizing and intra pulse coherent processing
subsystems are directly added to conventional digitizers and
interferometers to upgrade their functional capabilities as well as
removing multiple pulse requirements for these instruments.
BRIEF DESCRIPTION OF THE DRAWING
A complete understanding of the present invention may be gained by
considering the following detailed description in conjunction with
the accompanying drawings, in which:
FIG. 1 shows a block diagram of an optical fiber RF delay loop for
use in fabricating embodiments of the present invention;
.Iadd.FIG. 1a shows a block diagram of a tapped optical fiber RF
delay line or a set of optical fiber RF delay lines for use in
fabricating embodiments of the present invention; .Iaddend.
FIG. 2 shows a block diagram of an RF signal train generator for
use in fabricating embodiments of the present invention;
.Iadd.FIG. 2a shows a block diagram of data flow from RF receiver
to a medium for use in fabricating embodiments of the present
invention; .Iaddend.
FIG. 3 shows a block diagram of an interferoceiver for use in
fabricating embodiments of the present invention;
FIG. 4 shows a block diagram of an interferoceiver with a system
under test inserted into a path for use in fabricating embodiments
of the present invention;
FIG. 5 shows a block diagram of an interferoceiver with a system
under test as the splitter for use in fabricating embodiments of
the present invention;
.Iadd.FIG. 6 shows a block diagram of some sources for use in
fabricating embodiments of the present invention;.Iaddend.
.Iadd.FIG. 7 shows a block diagram of some RF receiver functions
for use in fabricating embodiments of the present invention.
.Iaddend.
DETAILED DESCRIPTION
FIG. 1 shows a block diagram of an optical fiber RF delay loop 100
for use in fabricating embodiments of the present invention. This
is the same optical fiber RF delay loop as in the parent patent
applications of optical fiber based radars and optical RF stereo.
As shown in FIG. 1, the optical RF signals through optical fiber
121 are applied as input to switchable coupler 120. Switchable
coupler 120 switches the optical RF signals from optical fiber 121
into optical fiber loop 110. Isolator 140 assures the optical RF
signals in optical fiber loop circulating only in one direction. As
the optical RF signals circulate the optical fiber loop 110, the
strength of optical RF signals reduces. The reduction is
compensated by in-line optical amplifier (OA) 130 to keep the
optical RF signals circulating in the loop again and again until
switchable coupler 120 is closed. A portion of optical RF signals
is switched from optical fiber loop 110 to optical fiber 122 and
the remainder of optical RF signals will still circulate in optical
fiber loop 110. The steps repeat again and again. The closing of
loop switch 150 will quench the circulation of optical RF signals
in optical fiber loop 110 before admitting any new arrivals of
optical RF signals from optical fiber 121. Switchable coupler 120,
in-line optical amplifier 130, isolator 140 and loop switch 150 are
well known to those of ordinary skill in the art.
.Iadd.FIG. 1a shows a block diagram of a tapped optical fiber RF
delay line or a set of optical fiber RF delay lines for use in
fabricating embodiments of the present invention. The optical RF
signals through optical fiber 121 are applied as input to taps or
splitter 1120. Taps or splitter 1120 splits the optical RF signals
and applies the split optical RF signals as input to optical fiber
RF delay lines 11111, 11112, . . . , 1111n. These delay lines have
different lengths. Taps or combiner 1121 combines the optical RF
signals from the optical fiber RF delay lines 11111,11112, . . . ,
1111n, and applies the combined optical RF signals as input to
optical fiber 122. Taps, splitter, and combiner are well known to
those of ordinary skill in the art. .Iaddend.
FIG. 2 shows a block diagram of an RF signal train generator 200
for use in fabricating embodiments of the present invention. This
is the same RF signal train generator as in the parent patent
application of optical fiber based radars. RF signal train
generator 200 comprises two identical optical fiber RF delay loops
according to the present invention. As shown in FIG. 2, two
temporally aligned RF pulses 210 and 220 are applied as inputs to
their respective optical fiber delay loops 230 and 240. So as not
to loose clarity, optical fiber RF up and down converters, and low
noise amplifiers have not been depicted in FIG. 2. Loops 230 and
240 are identical and operated in a same manner thus respectively
producing two pulse trains 250 and 260.
As those of ordinary skill in the art will readily appreciate,
embodiments of the present invention may not comprise an optical
fiber RF storage subsystem as in comparison with optical fiber
based radars for temporal alignment of two input pulses. The path
length difference of two paths from a source to the RF signal train
generator usually is small and can be simply adjusted through
conventional RF means, which are known to those of ordinary skill
in the art. However, if the need arises, one may introduce an
optical fiber RF storage subsystem as well. Embodiment of the
optical fiber RF storage subsystem is described in the parent
patent application of optical fiber based radars. Furthermore, one
may double one of the optical fiber delay loop in the RF signal
train generator as the optical fiber RF storage subsystem.
RF receiver (RFR) 30 uses direct digitizing and coherent receiving
methods to process pulse trains 250 and 260 from RF signal train
generator 200. These methods are well known to those of ordinary
skill in the art. The direct digitizing method uses one train as
triggering pulses to instruct the digitizer to sample the
respective pulses of the second train. The triggering is
systematically delayed in sampling the sequential pulses of the
second train. The direct digitizing method yields the intrinsic
structure of the initial pulse, which generates the second pulse
train. The coherent receiving method, based on the intra pulse
coherence, uses the pulses of one train as reference to process
variational differences of their respective pulses of the second
train. The mechanism to achieve intra pulse coherence was proposed
in the parent patent application of optical fiber based bistatic
radar. The coherent receiving method yields the relative amplitudes
and phases, or the relative frequency differences between RF pulses
210 and 220. Furthermore, RFR 30 will correlate pulse trains 250
and 260 to achieve a precise determination of their variational
differences. The manner in which RFR 30 processes RF pulse trains
is well known to those of ordinary skill in the art. As those of
ordinary skill in the art will readily appreciate, RF signal train
generator 200 of the present invention virtually mimics multiple
pulses for RFR 30 to decipher the information contained in RF
pulses 210 and 220.
As those of ordinary skill in the art will readily appreciate,
embodiments other than the specific architecture shown in FIG. 2
may be fabricated to provide the RF signal train generator. The
optical fiber may vary its electrical length under external
controls as a variable delay line. The optical fiber RF delay loop
may be replaced by a tapped optical fiber RF delay line or by a set
of optical fiber RF delay lines.Iadd., as shown in FIG.
1a.Iaddend..
.Iadd.FIG. 2a shows a block diagram of data flow from RF receiver
to a medium for use in fabricating embodiments of the present
invention. After processing, RF receiver 30 produces a data stream
301. The data stream 301 is then sent to medium 302..Iaddend.
.Iadd.FIG. 6 shows a block diagram of some sources for use in
fabricating embodiments of the present invention. Source (610) for
an interferoceiver may be acoustical (601), electromagnetic (602),
mechanical (603), infrared (604), optical (605), nuclear (606), or
other types..Iaddend.
.Iadd.FIG. 7 shows a block diagram of some RF receiver functions
for use in fabricating embodiments of the present invention. RF
receiver (30) for an interferoceiver has one or many capabilities
including those of amplitude and phase measurements (31), relative
amplitude and phase determination (32), frequency measurement (33),
relative frequency difference determination (34), correlation (35),
and signal delay determination (36). .Iaddend.
FIG. 3 shows a block diagram of an interferoceiver for use in
fabricating embodiments of the present invention. As shown in FIG.
3 the interferoceiver is comprised of source 310, splitter 320,
converters 323 and 324, RF signal train generator 200, and RF
receiver 30. Source 310, splitter 320, converters 323 and 324 are
well known to those of ordinary skill in the art.
During an operation, source 310 generates acoustical,
electromagnetic, or optical signals for transit along path 311.
Splitter 320 uses the signals from path 311 as input and outputs
two split signals. Furthermore, splitter 320 applies two split
signals to two paths 321 and 322 for transit to converters 323 and
324. Converters 323 and 324 then use the signals from paths 321 and
322 as inputs and convert them respectively to optical RF signals.
Converters 323 and 324 may simply pass through these signals, if
conversions are not needed. Converters 323 and 324 further apply
optical RF signals respectively from paths 321 and 322 to optical
fiber paths 325 and 326 for transit to RF signal train generator
200. RF signal train generator 200 uses optical RF signals as input
and outputs two pulse trains with respective to optical RF signals
from paths 325 and 326. RF signal train generator 200 further
applies two pulse trains respectively to optical fiber paths 327
and 328 for transit to RFR 30. RFR 30 uses pulse trains from
optical fiber paths 327 and 328 as inputs to process these two
pulse trains.
RFR 30 may further comprise phase shifters and delay lines for
processing transient signals from source 310. Furthermore, as is
well known to those of ordinary skill in the art, RFR 30 will yield
the spectrum of the signals, transient and intrinsic
characteristics of source 310, and turbulence characteristics of
the media surrounding source 310.
As those of ordinary skill in the art will readily appreciate,
embodiment of interferoceiver 300 will leads to investigation of
many transient and nonrepeatable signals in acoustics,
electromagnetism, and optics. Those signals in acoustics are the
blasts, explosions, thunders, etc . . . . Those signals in
electromagnetism are electromagnetic pulses from lightning, violent
electromagnetic discharge, electromagnetic pulse of opportunity,
electromagnetic pulses emitted by nuclear blasts and celestial
objects, etc . . . . Those signals in optics are the lights emitted
by atoms and molecules in a turbulent media of burning, discharge,
plasma, lightning, etc . . . . Furthermore, all the above mentioned
signals are well know to those of ordinary skill in the art.
FIG. 4 shows a block diagram of an interferoceiver with a system
under test inserted into a path for use in fabricating embodiments
of the present invention. As shown in FIG. 4, interferoceiver 400
is comprised of source 410, splitter 420, converters 423 and 424,
RF signal train generator 200, and RF receiver 30. Source 410,
splitter 420, system under test 430, converters 423 and 424 are
well known to those of ordinary skill in the art.
During an operation, source 410 generates acoustical,
electromagnetic, or optical signals for transit along path 411.
Splitter 420 uses the signals from path 411 as input and outputs
two split signals. Furthermore, splitter 420 applies two split
signals to two paths 421 and 422 for transit to converters 423 and
325. Signal of path 422 transits through system under test 430.
Intrinsic charateristics of system under test 430 is random,
chaotic, turbulent, or transient. As those of ordinary skill in the
art will readily appreciate that signal of path 422 will interact
with system under test and be tainted with the intrinsic
characteristics of system under test 430 after the transit. Then
converters 423 and 424 use the signals from paths 421 and 422 as
inputs and convert them respectively to optical RF signals.
Converters 423 and 424 may simply pass through these signals, if
conversions are not needed. Converters 423 and 424 further apply
optical RF signals respectively from paths 421 and 422 to optical
fiber paths 425 and 426 for transit to RF signal train generator
200. RF signal train generator 200 uses optical RF signals as input
and outputs two pulse trains with respect to optical RF signals
from paths 425 and 426. RF signal train generator 200 further
applies two pulse trains respectively to optical fiber paths 427
and 428 for transit to RFR 30. RFR 30 uses pulse trains from
optical fiber paths 427 and 428 as inputs to process signal train
from path 428 by using signal train from path 427 as a reference.
As is well known to those of ordinary skill in the art, the
reference signals from splitter 420 through path 421, converter
423, path 425, RF signal train generator 200, path 427 to RFR 30
are protected from external contamination and interference.
As those of ordinary skill in the art will readily appreciate,
embodiment of interferoceiver 400 is well suited for investigating
random, chaotic, turbulent, or transient features of emitting
source 410 and system under test 430. The observed intrinsic traits
and variational differences contain information on both emitting
source 410 and system under test 430. With a known and pulsed
source 410, the processing of signal train from fiber optical path
428 by RFR 30 yields the intrinsic characteristics of the random,
chaotic, turbulent, or transient traits within system under test
430. As those of ordinary skill in the art will further appreciate,
a coincident circuit may be needed to coordinate the source pulse
with a transient event from system under test 430. Furthermore, RFR
30 will separate stable traits of system under test 430 from its
random, chaotic, turbulent, or transient features. The method of
separation is well known to those of ordinary skill in the art.
As those of ordinary skill in the art will readily appreciate,
embodiment of interferoceiver 400 with a pulsed ultrasonic source
410 will lead to diffraction tomography for unstable systems. An
unstable motion leads to Doppler shift disturbances in diffraction
fields and tomographic image blurring. Embodiment of
interferoceiver 400 will further lead to ultrasonic imaging of
unstable objects and of fetus. As it is well known to those of
ordinary skill in the art, RFR 30 through Fourier transformation
and moving center correction will remove Doppler shift disturbances
and sharp ultrasonic images of these systems.
As those of ordinary skill in the art will appreciate, embodiment
of interferoceiver 400 with a pulsed electromagnetic source 410
will use solid means of coaxial cables and wave guides to transit
its electromagnetic signals. For example, a single pulse from the
pulsed electromagnetic source 410 will lead to the determination of
location and speed for a fly in a transverse electromagnetic cell.
As is well known to those of ordinary skill in the art, a
conventional methods will only able to determine the location of a
fly at rest from a single electromagnetic pulse.
As those of ordinary skill in the art will readily appreciate,
embodiment of interferoceiver 400 may use .[.a.]. .Iadd.an
.Iaddend.electromagnetic pulse from lightning as a source and cloud
layers as system under test 430. RFR then will provide a detailed
information concerning the structures of these layers.
As those of ordinary skill in the art will appreciate, embodiment
of interferoceiver 400 with a continuous wave (CW) laser source 410
and .[.a.]. .Iadd.an .Iaddend.electromagnetic pulse sensor as
system under test 430 will lead to the capture of a single
electromagnetic event. Furthermore, RFR 30 will provide a detailed
information concerning transient traits and electromagnetic
spectrum of the event.
As those of ordinary skill in the art will further appreciate,
embodiment of interferoceiver 400 with a pulsed laser source 410
will lead to light scatterings by atoms, molecules, microorganisms,
medium fluctuations, plasmas, and particles suspended in chaotic
media, and many others. As is well known to those of ordinary skill
in the art, the scattered lights are affected by the initial
positions and velocities of micro objects and statistical
properties of media. As is well known to those of ordinary skill in
the art, motion of micro objects and turbulence of media will lead
to Doppler frequency shifts in scattered lights. As those of
ordinary skill in the art will appreciate, RFR 30 through Fourier
transformation will reveal the Doppler spectra associated with the
motion and turbulence, and their statistical distributions. As
those of ordinary skill in the art will appreciate, embodiment of
interferoceiver 400 will provide a much better tool than
conventional methods in revealing intrinsic characteristics of
atoms, molecules, microorganisms, medium fluctuations, plasmas, and
particles suspended in chaotic media, and many others.
As those of ordinary skill in the art readily appreciate,
embodiment of interferoceiver 400 with a pulsed laser source 410
will lead to lidars and laser velocimeters. Conventional lidars,
which are based on pulsed lasers, only measure the ranges of
reflecting objects. Conventional laser velocimeters, which are
based on CW lasers, only measure the Doppler shifts from seeded
particles. Lidars and laser velocimeters of the present invention,
with a help of optical fiber RF storage subsystems, will have both
the ranging and Doppler capabilities. As those of ordinary skill in
the art will further appreciate, the distinction between lidars and
laser velocimeters disappears in the teaching of the present
invention. With a subnanosecond pulse source, we will be able to
locate constituents in a large reflecting assembly and measure
their individual Doppler shift frequencies. As those of ordinary
skill in the art will readily appreciate, the teachings from the
parent patent applications of optical fiber based bistatic radar
and optical RF stereo will lead to the embodiments for fabricating
optical fiber based bistatic lidar and optical light stereo.
As those of ordinary skill in the art will further appreciate, the
incident and scattered laser pulses may be unsuitable for direct
feeding to optical fibers. A second laser can be deployed to down
convert the incident and scattered laser pulses to RF signals, then
with the help of optical fiber RF converters to up convert the RF
signals to optical RF signals for transit through optical fibers to
RF signal train generator. The processes of down and up conversions
of laser pulses are well known to those of ordinary skill in the
art.
FIG. 5 shows a block diagram of an interferoceiver with a system
under test as the splitter for use in fabricating embodiments of
the present invention. As shown in FIG. 5 interferoceiver 500 is
comprised of source 510, system under test 530, converters 523 and
524, RF signal train generator 200, and RF receiver 30. Source 510,
converters 523 and 524 are well known to those of ordinary skill in
the art.
During an operation, source 510 generates acoustical,
electromagnetic, or optical signals for transit along path 511.
System under test 530 uses the signals from path 511 as input,
interacts with the signals, and outputs two split signals.
Furthermore, system under test 530 applies two split signals to two
paths 521 and 522 for transit to converters 523 and 524. Then
converters 523 and 524 use the signals from paths 521 and 522 as
inputs and convert them respectively to optical RF signals.
Converters 523 and 524 may simply pass through these signals, if
conversions are not needed. Converters 523 and 524 further apply
optical RF signals respectively from paths 521 and 522 to optical
fiber paths 525 and 526 for transit to RF signal train generator
200. RF signal train generator 200 uses optical RF signals as input
and outputs two pulse trains with respective to optical RF signals
from paths 525 and 526. RF signal train generator 200 further
applies two pulse trains respectively to optical fiber paths 527
and 528 for transit to RFR 30. RFR 30 uses pulse trains from
optical fiber paths 527 and 528 as inputs to process signal train
from one path by using signal train from the other path as
reference.
As those of ordinary skill in the art will appreciate, for example,
embodiment of interferoceiver 500 with a pulsed laser source 510
will lead to the correlation of scattered lights in a light
scattering process. The correlation yields the Doppler shift
difference between two scattered lights. The mechanism of Doppler
shift difference determination was proposed in the parent patent
application of optical RF stereo. RFR 30 through Fourier
transformation will reveal the spectra of the Doppler shift
difference associated with the motion of micro objects and
turbulence of media, and their statistical distributions.
ADVANTAGES AND OBJECTIVES
Embodiments of the present invention will provide advanced means to
upgrade conventional digitizing receivers and interferometers than
those furnished by the prior art. As those of ordinary skill in the
art will further appreciate, embodiments of the present invention
provide added upgrades to the existing digitizing receivers and
interferometers without modification, which in turn will be more
cost effective and will not interrupt their normal operation.
Embodiments of the present invention will enhance the functional
diversities of conventional digitizing receivers and
interferometers. In addition, the use of RF signal train generators
makes it possible for digitizing receivers and interferometers to
completely decipher a single transient event without instability
blurring. Furthermore, embodiments of the present invention enable
digitizing receivers and interferometers to determine intrinsic
traits and Doppler spectrum of a single RF pulse.
Embodiments of the present invention will be able to reveal many
hidden mechanisms governing many statistical phenomena. For
instance, Doppler spectra of a chaotic medium and a turbulent flow
could not be directly observed. Statistical properties of the
Doppler spectra now can be systematically investigated. As those of
ordinary skill in the art will appreciate, embodiments of the
present invention will lead to better understandings of the chaotic
media and turbulent flows.
As those of ordinary skill in the art will readily appreciate,
averaging with respect to multiple pulses will smear many critical
information concerning the system under test. Embodiments of the
present invention use a single pulse rather than multiple
repetitive pulses. The embodiment will make digitizing receivers
and interferometers more versatile and sophisticated in exposing
many critical information. As those of ordinary skill in the art
will still further appreciate, embodiments of the present invention
will lead to better understandings of random, chaotic, turbulent,
or transient phenomena.
Embodiments of the present invention will be able to sharpen
ultrasonic images. Furthermore, embodiments of the present
invention will be able to separate the images of stationary
constituents from that of moving constituents. As those of ordinary
skill in the art will equally appreciate, optical fiber based
radars will also sharpen synthetic aperture radar (SAR) images, and
separate SAR images of stationary constituents from that of moving
constituents.
Embodiments of the present invention will be able to reveal
intrinsic traits of an active system. Intrinsic traits of an active
system .[.is.]. .Iadd.are .Iaddend.inherited, like imperfection in
a diamond. As those of ordinary skill in the art will equally
appreciate, optical fiber based radars and passive RF systems will
provide excellent means in revealing the unintended modulation on
pulse by active and passive objects.
Embodiments of the present invention will be advantageous to
disclose internal constituents of a system and to reveal their
characteristics. As those of ordinary skill in the art will equally
appreciate, optical fiber based radars and passive RF .[.system.].
.Iadd.systems .Iaddend.possess excellent means in suppression of
clutter returns and of multiple path interferences.
Embodiments of the present invention.Iadd., as shown in FIG. 2a,
.Iaddend.will lead to more effective means in deciphering a
transient event than a fast digitizer under development or a group
of parallel digitizers. A fast digitizer creates a massive data
stream in a very short time interval. It is difficult for a medium
to receive such a data stream.
Embodiments of the present invention will be advantageous in
destructive testings, for example, automobile collision tests.
Transient signals from various sensors will be thoroughly analyzed
by interferoceivers. Embodiments of the present invention will
provide better understandings as well as reducing the costs in
destructive tests.
Quantum mechanics is a mechanics of coherent. Many interesting
coherent phenomena implicated by Einstein, Podolsky, and Rosen
paradox are still waiting for us to discover. Embodiments of the
present invention will provide us new tools for us to discover
these interesting phenomena.
SUMMARY, RAMIFICATIONS, AND SCOPE
Those skilled in the art readily recognize that embodiments of the
present invention may be made without departing from its teachings.
For example, .[.the.]. interferoceivers may have many designs as
well as different variations. The source of an interferoceiver may
play the role of a splitter as well. Two signals at different angle
perspectives from a source are sent directly to the RF signal train
generator. An interferoceiver may compare two sequential events
from a source with the help from an optical fiber RF storage
subsystem to temporally align these two events. Such a comparison
leads to inter pulse coherence. The mechanism to achieve inter
pulse coherence was proposed in the parent patent application of
optical fiber based radars. Thus the scope of the invention should
be determined by appended claims and their legal equivalent, rather
by the examples presented here.
* * * * *