Canadian Patents Database / Patent 2165420 Summary

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(12) Patent: (11) CA 2165420
(54) English Title: SYSTEM AND METHOD FOR MODULATING A CARRIER FREQUENCY
(54) French Title: SYSTEME ET METHODE DE MODULATION DE FREQUENCE DE PORTEUSE
(51) International Patent Classification (IPC):
  • H03C 5/00 (2006.01)
(72) Inventors (Country):
  • LABRECHE, LOUIS (Canada)
  • LEPAGE, JEAN-PIERRE (Canada)
(73) Owners (Country):
  • THE CANADIAN SPACE AGENCY, AN AGENCY OF THE GOVERNMENT OF CANADA (Canada)
(71) Applicants (Country):
  • THE CANADIAN SPACE AGENCY, AN AGENCY OF THE GOVERNMENT OF CANADA (Canada)
(74) Agent: FRENCH, DAVID J.
(45) Issued: 2003-12-16
(86) PCT Filing Date: 1994-06-17
(87) PCT Publication Date: 1995-01-05
Examination requested: 1998-11-09
(30) Availability of licence: N/A
(30) Language of filing: English

(30) Application Priority Data:
Application No. Country Date
220,215 United States of America 1994-03-30
2,120,077 Canada 1993-06-17

English Abstract






A carrier frequency modulating system and method for producing a modulated carrier frequency is disclosed. The system comprises
a carrier frequency signal generator (23) for producing a carrier frequency signal at a carrier frequency at an output (42) thereof. The
system further comprises a sequencer (32) for producing a modulation signal at an output (35) thereof. This modulation signal comprises a
plurality of modulation signal portions (68, 68) separated by at least one null modulation signal portion (69) having a corresponding time
length. The system is provided with a modulator (46) for producing a modulated carrier frequency signal at an output (76) thereof. The
modulator (76) has a first input (44) connected to the output (42) of the carrier frequency signal generator (23) for receiving the carrier
frequency signal, and has a second input (48) for receiving the modulation signal. The system further comprises a power supply unit (55)
for supplying electrical power to the carrier frequency signal generator (23). The sequencer (32) is connected to the carrier frequency signal
generator (23) for controlling the activation thereof and to interrupt the carrier frequency signal generator (23) instead of modulating the
null modulation signal portion during the corresponding time length, whereby power consumption of the system is minimized.


French Abstract

L'invention concerne un système et un procédé qui permettent de produire une fréquence porteuse modulée. Le système comprend un générateur (23) de signal de fréquence porteuse qui produit un tel signal à une fréquence porteuse au niveau d'une sortie (42). Ce système comporte aussi un séquenceur (32) qui produit un signal de modulation au niveau d'une sortie (35). Ce signal de modulation comprend plusieurs parties (68) séparées par au moins une partie (69) de signal à modulation nulle émise pendant une durée correspondante. Ce système comporte un modulateur (46) qui produit au niveau d'une sortie (76) un signal de fréquence porteuse modulée. Ce modulateur (76) présente une première entrée (44), connectée à la sortie (42) du générateur (23) de signal de fréquence porteuse (23), afin de recevoir ce signal, et il présente une deuxième entrée (48) destinée à recevoir le signal de modulation. Le système comprend en outre une unité d'alimentation (55) qui fournit l'énergie électrique au générateur (23) de signal de fréquence porteuse. Le séquenceur (32), connecté à ce générateur (23), en commande l'activation et l'interrompt plutôt que de moduler la partie de signal à modulation nulle, pendant sa durée correspondante, ce qui permet de réduire la consommation d'énergie du système.


Note: Claims are shown in the official language in which they were submitted.


35

CLAIMS

1. A carrier frequency modulating system
comprising:

a carrier frequency signal generator
(99) for producing.a carrier frequency signal at a
carrier frequency at an output (42) thereof;
a sequences (32) for producing a
modulation signal at an output (35) thereof, said
modulation signal comprising a plurality of
modulation signal portions (68,68) separated by
at least one null modulation signal portion (69)
having a corresponding time length;
a modulator (46) for producing a
modulated carrier frequency signal at an output
(76) thereof, said modulator having a first input
(44) connected to the output of said carrier
frequency signal generator for receiving said
carrier frequency signal, and having a second
input (48) for receiving said modulation signal;
a power supply means (55) for supplying
electrical power to said carrier frequency signal
generator;
wherein said sequences (32) is connected
to said carrier frequency signal generator (99)
for controlling the activation thereof and to
interrupt said carrier frequency signal generator
instead of modulating said at least one null
modulation signal portion (69) during said
corresponding time length.

2. A carrier frequency modulating system as
claimed in claim 1, wherein said carrier frequency
signal generator (99) comprises:
an oscillator (72) for producing a first
signal at a first frequency at an output (71)
thereof ;


36

a harmonic generator (22) having an
input (26) connected to the output (71) of said
oscillator to produce a second signal comprising a
plurality of harmonic frequencies at an output
(40) thereof, said harmonic frequencies being
higher than said first frequency;

a bandpass filter means (49) having an
input (38) connected to the output (40) of said
harmonic generator to select a substantially
narrow frequency band centered at a single
harmonic frequency from said harmonic frequencies
thereby producing a corresponding carrier
frequency signal at said carrier frequency at an
output thereof;
wherein said sequencer (32) is connected
to said oscillator and said harmonic generator for
controlling the activation thereof.

3. A carrier frequency modulating system as
claimed in claim 1, wherein said carrier frequency
signal generator (99) comprises:

an oscillator (72) for producing a first
signal at a first frequency at an output (71)
thereof;

signal frequency multiplying means (18)
having an input (30) connected to the output (71)
of said oscillator to produce a second signal at a
second frequency at an output (28) thereof, said
second frequency being higher than said first
frequency;
a harmonic generator (22) having an
input (26) connected to the output (28) of said
frequency multiplying means (18) to produce a
third signal comprising a plurality of harmonic
frequencies at an output (40) thereof, said


37
harmonic frequencies being higher than said second
frequency;

a bandpass filter means; (49) having an
input (38) connected to the output (40) of said
harmonic generator (22) to select a substantially
narrow frequency band centered at a single
harmonic frequency from said harmonic frequencies
thereby producing a corresponding carrier
frequency signal at said carrier frequency at an
output thereof;

wherein said sequencer (32) is connected
to said frequency multiplying means (18) and said
harmonic generator (22) for controlling the
activation thereof.

4. A carrier frequency modulating system as
claimed in claim 2 or 3, further comprising a
second bandpass filter means (150) having an input
(73) connected to the output (76) of said
modulator (46) to attenuate frequencies adjacent
said carrier frequency thereby producing a single
frequency modulated carrier frequency signal.

5. A carrier frequency modulating system as
claimed in claim 1, further comprising antenna
means (78) coupled to the output (76) of said
modulator, to transmit said modulated carrier
frequency signal.

6. A carrier frequency modulating system as
claimed in claim 5, further comprising a variable
attenuator (74) having an input (73) connected to
the output (76) of said modulator (46) for
coupling said modulator output (76) to said
antenna means (78), said sequencer (32) being
connected to said variable attenuator (74) for


38

controlling the output level of said modulated
carrier frequency signal at an output (75)
provided on said variable attenuator (74).

7. A carrier frequency modulating system as
claim in claim 6, wherein said sequencer (32)
comprises a digital to analog converter (163),
said sequencer being connected to said variable
attenuator (74) through said digital to analog
converter (163).

8. A carrier frequency modulating system as
claimed in claim 2 or 3, wherein said bandpass
filter means 49 comprises a bandpass filter (118)
and a lowpass filter (124) connected in series
with said bandpass filter (118), said lowpass
filter having a cutoff frequency higher than said
single harmonic frequency and being in a range
near said single frequency;
whereby said carrier frequency signal is
substantially free of interference harmonic
frequencies generated by said bandpass filter
(118).

9. A carrier frequency modulating system as
claimed in claim 3, wherein said frequency
multiplying means (18) comprises at least one
frequency multiplier and a bandpass filter
connected in series with said at least one
frequency multiplier, said bandpass filter having
a bandwidth substantially centered on said second
frequency.

10. A carrier frequency modulating system as
claimed in claim 2 or 3, wherein said harmonic
generator (22) comprises a clipping amplifier (84)



39

connected to an impedance matching circuit (94) to
produce an amplified signal at an output (94)
thereof, and a step recovery diode (108) having a
terminal (106) connected to the output (94) of
said impedance matching circuit, whereby said
amplified signal drives said step recovery diode
(108) for producing said third signal.

11. A carrier frequency modulating system as
claimed in claim 1, wherein at least one of said
modulation signal portions (68,68) comprises at
least one phase modulation signal section (68).

12. A carrier frequency modulating system as
claimed in claim 1, wherein at least one of said
modulation signal portions (68,68) comprises at
least one amplitude modulation signal section
(68).

13. A carrier frequency modulating system as
claimed in claim 1, said wherein at least one of
said modulation signal portions (68,68) comprises
at least one phase modulation signal section (68)
and at least one of said modulation signal
portions comprises at least one amplitude
modulation signal section (68), said modulated
carrier frequency signal comprising respectively
at least one phase modulated carrier frequency
signal and at least one amplitude modulated
carrier frequency signal.

14. A carrier frequency modulating system as
claimed in claim 11 or 13, wherein said first
input (44) of said modulator is connected at a
first connecting node (126) to respective inputs
(127,128) of first and second conducting paths
(129,130) having a difference in length


40

substantially equal to half a wavelength
corresponding to said carrier frequency, said
conducting paths (129,130) having respective
outputs (132,133) being connected to the output
(76) of said modulator at a second connecting node
(135), said modulator further comprising a
switching means (131) connected to said input (48)
for receiving said modulation signal, said
switching means (131) being connected to said
conducting paths (129,130) to successively
activate only one of said conducting paths
(129,130) at a time, whereby to produce said phase
modulated carrier frequency portion of said
modulated carrier frequency.

15. A carrier frequency modulating system as
claimed in claim 14, wherein each of said
conducting paths (129,130) comprises first and
second portions (136,137,136,137) connected
respectively by third and fourth nodes (138,139)
which are spaced from said first node (126) by a
distance substantially equal to half a wavelength
corresponding to said carrier frequency, the
second portion (137) of said first conducting path
(129) having a length separating said third node
(138) from said second node (135) by a distance
substantially equal to three quarter a wavelength
corresponding to said carrier frequency, the
second portion (137) of said second conducting
path (130) having a length separating said fourth
node (139) from said second node (135) by a
distance substantially equal to half a wavelength
corresponding to said carrier frequency, whereby
to provide said half a wavelength difference in
length of said conducting paths (129,130), said
switching means (131) being connected to said


41

first and second conducting paths (129,130)
respectively at said third and fourth nodes
(138,139).

16. A carrier frequency modulating system as
claimed in claim 15, wherein said switching means
(131) comprises first and second diodes (140,141)
having opposed polarity terminals (143,145) being
connected to said input (48) for receiving said
modulation signal and being connected to a ground
(142) of said system, each terminal of a second
pair of opposed polarity terminals (146,148) being
respectively connected to said third and fourth
connecting nodes (138,139), whereby said carrier
frequency signal traverses said first conducting
path (129) whenever said second diode (141) is
caused to conduct by said modulation signal, said
carrier frequency signal traversing said second
conducting path (130) whenever said first diode
(140) is caused to conduct by said modulation
signal.

17. A carrier frequency modulating system as
claimed in claim 1 or 2 or 3, wherein said
sequencer (32) comprises a digital generator (156)
for producing a digital modulation signal and
control signals for said carrier frequency signal
generator (99). said sequencer (32) further
comprising a digital to analog converter (161)
receiving said digital modulation signal for
producing said modulation signal.

18. A carrier frequency modulating system as
claimed in claim 17, wherein said digital to
analog converter (161) is provided with a voltage



42

to current converting means (316) to produce said
modulation signal.

19. ~A carrier frequency modulating system as
claimed in claim 18, wherein said digital
modulation signal comprises a delta modulation
signal portion, said digital to analog converter
(161) comprising:
means (264) for generating a reference
clock signal; means (261) for decoding said
digital modulation, said decoding means comprising
a shift register (282) for successively storing a
sample of said digital modulation upon receipt of
said reference clock signal, whenever said
decoding means has detected sampling actuation
data comprised in said digital modulation signal,
said decoder producing at a first output (286)
thereof a pre integration signal whose
characteristics are determined according to a
predetermined code represented by said sample;
integrating means (290) having an input
(288) receiving said pre integration signal for
integration thereof, said integrating means (290)
producing an integrated amplitude signal at an
output (292) thereof, said integrating means (29)
limiting said integrated amplitude signal to a
null or positive value:
first lowpass filter means (310)
receiving said integrated amplitude signal and
coupled to an input (314) provided on said voltage
to current converting means.

20. ~A carrier frequency modulating system as
claimed in claim 19, wherein said digital to
analog converter (161) further comprises:


43

port selector means (268) having a
control input (267) and an output (271), said
decoding means (261) having a second output (266)
for sending a port selection control signal to
said control input (267) of said port selector
means (268), and a third output (270) for
producing an alternate modulation analog signal,
said port selector means further having a first
input port (272) for receiving said alternate
modulation analog signal and a second input port
(278) coupled to said integrating means output;
said port selector means (268)
connecting said first input port (272) to said
selector output (271) whenever said decoding means
(261) has detected alternate modulation actuation
data comprised in said digital modulation signal
and has sent a corresponding selection control
signal to said port selector means (268), said
part selector means output (271) thereby sending
said integrated amplitude signal to said first
lowpass filter means (310);
said port selector means (268)
connecting said second input port (278) to said
selector output (271) whenever said decoding means
has detected sampling actuation data comprised in
said digital modulation signal and has sent a
corresponding selection control signal to said
port selector means (268), said port selector
means output thereby sending said alternate
modulation analog signal to said first lowpass
filter means (310).

21. A carrier frequency modulating system as
claimed in claim 20, wherein said alternate
modulation is a phase modulation.


44

22. A carrier frequency modulating system as
claimed in claim 21, wherein said digital to
analog converter (161) further comprises:
a second lowpass filter means (274)
coupled to said decoding means third output (270)
for filtering said alternate modulation analog
signal prior to feeding said selector means first
input port (272).

23. A carrier frequency modulating system as
claimed in claim 12, wherein said sequencer (32)
causes the amplitude of said amplitude modulation
signal to vary in successive increasing or
decreasing predetermined steps separated by
predetermined time periods, whereby said modulator
(46) produces an amplitude modulated carrier
frequency signal having a corresponding
predetermined envelope.

24. A carrier frequency modulating system as
claimed in claim 2 or 3, wherein at least one of
said modulation signal portions (68,68) comprises
at least one amplitude modulation signal section
(68), and wherein said sequencer (32) causes the
amplitude of said amplitude modulation signal to
vary in successive increasing or decreasing
predetermined steps separated by predetermined
time periods, whereby said modulator produces an
amplitude modulated carrier frequency signal
having a corresponding predetermined envelope.

25. A carrier frequency modulating system as
claimed in claim 24, wherein said sequences (32)
causes said harmonic generator (22) to be
successively activated before an amplitude
modulation period and deactivated after said


45

amplitude modulation period, said at least a
portion of said amplitude modulation signal being
produced while said harmonic generator is
activated during said amplitude modulation period.

26. A carrier frequency modulating system as
claimed in claim 1, wherein said sequencer (32)
further comprises:
a sequence mode selector (162) for
selecting from a plurality of modes associated
with a plurality of functions sequences a mode
associated with a respective sequence of functions
to be provided in said modulation signal, said
sequence mode selector (162) sending a signal
indicating said selected mode at an output (164)
thereof;
a function address generator (168)
having an input (166) connected to the output
(164) of said sequence mode selector (162), said
function address generator (168) comprising a
memory (170) for storing function addresses
(172,172) associated with each sequence of said
plurality of sequences corresponding to said
plurality of modes, said function address
generator (168) being responsive to said signal
indicating said selected mode to produce at a
first output (174) thereof a first function
address signal associated with a first function
(182) corresponding to said selected mode;
a function element address generator
(176) having an input (178) connected to the first
output (174) of said function address generator
(168), said function element address generator
(176) receiving said first function address signal
associated with said selected mode, said function
element address generator (176) producing at a


46

first output (180) thereof a function element
address signal associated with at least one
function element constituting said first function
(182) of said selected mode;
a function memory (181) having an input
(179) connected to the first output (180) of said
function element address generator (176) for
receiving said function element address signal,
said function memory (181) storing at
corresponding addresses (183,185) modulation
information associated with said at least one
element of said first function (182), and for
storing at corresponding addresses
(190,187,192,189) information associated with at
least one additional function element associated
with a plurality of additional functions
(184,186), said modulation information associated
with said function elements comprising modulation
and control data and timing data, said function
memory (181) producing at a first output (199)
thereof a composite digital modulation signal
comprising modulation and control data
corresponding to said function element address
signal associated with at least one function
element constituting said first function (182) of
said selected mode, said function memory (181)
producing at a second output (200) a timing signal
representing said timing data corresponding to
said function element address signal associated
with at least one function element constituting
said first function (182) of said selected mode;
a function timer (203) for producing at
an output thereof a timing reference signal into a
first input (205) of a timing comparator (206)
having a second input (208) connected to the
second output (200) of said function memory (181)


47

for receiving said timing data signal, to produce
a transmission control signal at an output (209)
thereof whenever the value of said timing data
signal equals the value of said timing reference
signal;
a buffer (210) having a first input
(211) connected to the first output (199) of said
function memory (181) to receive and store said
composite digital modulation signal comprising
modulation and control data corresponding to said
function element address signal associated with at
least one function element constituting said first
function (182) of said selected mode, said buffer
(210) having a driver (216) provided with a
digital modulation signal output (218) and a first
control output means (219,220) connected to said
carrier frequency signal generator (99), said
buffer (210) has a second input (213) connected to
the output (214) of said timing comparator (206)
for receiving said transmission control signal,
whereby to cause said driver (216) to transmit a
digital modulation signal comprising modulation
data through said digital modulation signal output
(218) and to cause said driver (216) to transmit
control signal for said carrier frequency signal
generator (23) through said first control output
means(219,220);
wherein said function element address
generator (176) has a second input (224) connected
to the output (209) of said timing comparator
(206) for receiving said transmission control
signal, to cause said function element address
generator (176) to increment said function address
element signal whereby to produce at the output
(180) of said function element address generator a
function next element address to be transmitted to


48

said function memory (181) whenever data
corresponding to said function next element
address differs from an end of function code, said
function element address generator means (176)
producing an end of function signal at a second
output (235) thereof whenever said data
corresponding to said function next element
address corresponds to said end of function code,
said second output (235) being connected to a
first input (208) provided on said function timer
(237) for resetting said function timer (237);
said system further comprising a
function sequence counter (238) having a first
input (239) connected to the second output (235)
of said function element address generator (176)
for receiving said end of function signal, to
cause said function sequence counter (238) to be
incremented and to produce at an output (240)
thereof a next function control signal to a second
input (241) provided on said function address
generator (168), causing said function address
generator (168) to produce at said first output
(174) thereof a next function address signal
associated with a next function (183,184) to be
transmitted for the corresponding selected mode
whenever said next function address differs from
an end of sequence code, thereby causing said
function element address generator (176) to
produce at said first output (180) thereof a
function element address signal associated with at
least one function element constituting said next
function (183,184) of said selected mode whenever
data corresponding to said function next element
address differs from said end of function code,
thereby causing said function memory (181) to
produce at said first output (199) thereof a


49

composite digital modulation signal comprising
modulation and control data corresponding to said
function element address signal associated with at
least one function element constituting said next
function (183,184) of said selected mode, thereby
causing said driver (216) to transmit a
corresponding digital modulation signal containing
modulation data through said digital modulation
signal output (218) and to cause said driver (216)
to transmit corresponding control signal for said
carrier frequency signal generator (23) through
said first control output means (219,220), said
function address generator (168) producing an end
of sequence signal at a second output (243)
thereof whenever said next function corresponds to
said end of sequence code, said second output
(243) being connected to a second input (247)
provided on said function sequence counter (238)
for resetting said sequence counter (238) after
completion of the transmission of a last function
of said function sequence corresponding to said
selected mode;
a reference clock signal generating
means (248) having an output (249) sending a
reference clock signal respectively to a second
input (250) provided on said function timer (202),
to a third input (253) provided on said function
sequence counter (238) and to a third input (256)
provided on said function element address
generator.

27. A carrier frequency modulating
system as claimed in claim 2, wherein said
sequencer (32) further comprises:
a sequence mode selector (162) for
selecting from a plurality of modes associated




50


with a plurality of function sequences a mode
associated with a respective sequence of functions
to be provided in said modulation signal, said
sequence mode selector (162) sending. a signal
indicating said selected mode at an output (164)
thereof;

a function address generator (168)
having an input (166) connected to the output
(164) of said sequence mode selector (162), said
function address generator (168) comprising a
memory (170) for storing function addresses
(172,172) associated with each sequence of said
plurality of sequences corresponding to said
plurality of modes, said function address
generator (168) being responsive to said signal
indicating said selected mode to produce at a
first output (174) thereof a first function
address signal associated with a first function
(182) corresponding to said selected mode;

a function element address generator
(176) having an input (178) connected to the first
output (174) of said function address generator
(168), said function element address generator
(176) receiving said first function address signal
associated with said selected mode, said function
element address generator (176) producing at a
first output (180) thereof a function element
address signal associated with at least one
function element constituting said first function
(182) of said selected mode;

a function memory (181) having an input
( 179 ) connected to the first output (180) of said
function element address generator (176) for
receiving said function element address signal,
said function memory (181) storing at
corresponding addresses (183,185) modulation




51


information associated with said at least one
element of said first function (182), and for
storing at corresponding addresses
(190,187,192,189) information associated with at
least one additional function elements associated
with a plurality of additional functions
(184,186), said modulation information associated
with said function elements comprising modulation
and control data and timing data, said function
memory (181) producing at a first output (199)
thereof a composite digital modulation signal
comprising modulation and control data
corresponding to said function element address
signal associated with at least one function
element constituting said first function (182) of
said selected mode, said function memory (181)
producing at a second output (200) a timing signal
representing said timing data corresponding to
said function element address signal associated
with at least one function element constituting
said first function (182) of said selected mode;

a function timer (203) for producing at
an output thereof a timing reference signal into a
first input (205) of a timing comparator (206)
having a second input (208) connected to the
second output (200) of said function memory (181)
for receiving said timing data signal, to produce
a transmission control signal at an output (209)
thereof whenever the value of said timing data
signal equals the value of said timing reference
signal;

a buffer (210) having a first input
(211) connected to the first output (199) of said
function memory (181) to receive and store said
composite digital modulation signal comprising
modulation and control data corresponding to said




52


function element address signal associated with at
least one function element constituting said first
function (182) of said selected mode, said buffer
(210) having a driver (216) provided with a
digital modulation signal output (218) and first
and second control outputs (219,220) respectively
connected to said frequency multiplying means (18)
and harmonic generator (22), said buffer (210) has
a second input (213) connected to the output (214)
of said timing comparator (206) for receiving said
transmission control signal, whereby to cause said
driver (216) to transmit a digital modulation
signal comprising modulation data through said
digital modulation signal output (218) and to
cause said driver (216) to transmit control
signals for said frequency multiplying means (18)
and harmonic generator (22) respectively through
said first and second control outputs (219,220);

wherein said function element address
generator (176) has a second input (224) connected
to the output (209) of said timing comparator
(206) for receiving said transmission control
signal, to cause said function element address
generator (176) to increment said function address
element signal whereby to produce at the output
(180) of said function element address generator a
function next element address to be transmitted to
said function memory (181) whenever data
corresponding to said function next element
address differs from an end of function code, said
function element address generator means (176)
producing an end of function signal at a second
output (235) thereof whenever said data
corresponding to said function next element
address corresponds to said end of function code,
said second output (235) being connected to a





53


first input (208) provided on said function timer
(237) for resetting said function timer (237);

said system further comprising a
function sequence counter (238) having a first
input (239) connected to the second output (235)
of said function element address generator (176)
far receiving said end of function signal, to
cause said function sequence counter (238) to be
incremented and to produce at an output (240)
thereof a next function control signal to a second
input (241) provided on said function address
generator (168), causing said function address
generator (168) to produce at said first output
(174) thereof a next function address signal
associated with a next function (183,184) to be
transmitted for the corresponding selected mode
whenever said next function address differs from
an end of sequence code, thereby causing said
function element address generator (176) to
produce at said first output (180) thereof a
function element address signal associated with at
least one function element constituting said next
function (183,184) of said selected mode whenever
data corresponding to said function next element
address differs from an end of function code,
thereby causing said function memory (181) to
produce at said first output (199) thereof a
composite digital modulation signal comprising
modulation and control data corresponding to said
function element address signal associated with at
least one function element constituting said next
function (183,184) of said selected mode, thereby
causing said driver (216) to transmit a
corresponding digital modulation signal containing
modulation data through said digital modulation
signal output (218) and to cause said driver (216)




54


to transmit corresponding control signals for said
frequency multiplying means (18) and harmonic
generator (22) respectively through said first and
second control outputs (219,220),said function
address generator (168) producing an end of
sequence signal at a second output (243) thereof
whenever said next function corresponds to said
end of sequence code, said second output (243)
being connected to a second input (247) provided
on said function sequence counter (238) for
resetting said sequence counter (238) after
completion of the transmission of a last function
of said function sequence corresponding to said
selected mode;

a reference clock signal generating
means (248) having an output (249) sending a
reference clock signal respectively to a second
input (250) provided on said function timer (202),
to a third input (253) provided on said function
sequence counter (238) and to a third input (256)
provided on said function element address
generator.

28. A carrier frequency modulating system as
claimed in claim 3, wherein said sequencer (32)
further comprises:

a sequence mode selector (162) for
selecting from a plurality of modes associated
with a plurality of function sequences a mode
associated with a respective sequence of functions
to be provided in said modulation signal, said
sequence mode selector (162) sending a signal
indicating said selected mode at an output (164)
thereof;

a function address generator (168)
having an input (166) connected to the output




55

(164) of said sequence mode selector (162), said
function address generator (168) comprising a
memory (170) for storing function addresses
(172,172) associated with each sequence of said
plurality of sequences corresponding to said
plurality of modes, said function address
generator (168) being responsive to said signal
indicating said selected mode to produce at a
first output (174) thereof a first function
address signal associated with a first function
(182) corresponding to said selected mode;

a function element address generator
(176) having an input (178) connected to the first
output (174) of said function address generator
(168), said function element address generator
(176) receiving said first function address signal
associated with said selected mode, said function
element address generator (176) producing at a
first output (180) thereof a function element
address signal associated with at least one
function element constituting said first function
(182) of said selected mode;

a function memory (181) having an input
(179) connected to the first output (180) of said
function element address generator (176) for
receiving said function element address signal,
said function memory (181) storing at
corresponding addresses (183,185) modulation
information associated with said at least one
element of said first function (182), and for
storing at corresponding addresses
(190,187,192,189) information associated with at
least one additional function elements associated
with a plurality of additional functions
(184,186), said modulation information associated
with said function elements comprising modulation






56


and control data and timing data, said function
memory (181) producing at a first output (199)
thereof a composite digital, modulation signal
comprising modulation and control data
corresponding to said function element address
signal associated with at least one function
element constituting said first function (182) of
said selected mode, said function memory (181)
producing at a second output (200) a timing signal
representing said timing data corresponding to
said function element address signal associated
with at least one function element constituting
said first function (182) of said selected mode;

a function timer (203) for producing at
an output thereof a timing reference signal into a
first input (205) of a timing comparator (206)
having a second input (208) connected to the
second output (200) of said function memory (181)
for receiving said timing data signal, to produce
a transmission control signal at an output (209)
thereof whenever the value of said timing data
signal equals the value of said timing reference
signal;

a buffer (210) having a first input
(211) connected to the first output (199) of said
function memory (181) to receive and store said
composite digital modulation signal comprising
modulation and control data corresponding to said
function element address signal associated with at
least one function element constituting said first
function (182) of said selected mode, said buffer
(210) having a driver (216) provided with a
digital modulation signal output (218) and first
and second control outputs (219,220) respectively
connected to said oscillator (72) and harmonic
generator (22), said buffer (210) has a second





57


input (213) connected to the output (214) of said
timing comparator (206) for receiving said
transmission control signal, whereby to cause said
driver (216) to transmit a digital modulation
signal comprising modulation data through said
digital modulation signal output (218) and to
cause said driver (216) to transmit control
signals for said oscillator (72) and harmonic
generator (22) respectively through said first and
second control outputs (219,220);

wherein said function element address
generator (176) has a second input (224) connected
to the output (209) of said timing comparator
(206) for receiving said transmission control
signal, to cause said function element address
generator (176) to increment said function address
element signal whereby to produce at the output
(180) of said function element address generator a
function next element address to be transmitted to
said function memory (181) whenever data
corresponding to said function next element
address differs from an end of function code, said
function element address generator means (176)
producing an end of function signal at a second
output (235) thereof whenever said data
corresponding to said function next element
address corresponds to said end of function code,
said second output (235) being connected to a
first input (208) provided on said function timer
(237) for resetting said function timer (237);

said system further comprising a
function sequence counter (238) having a first
input (239) connected to the second output (235)
of said function element address generator (176)
for receiving said end of function signal, to
cause said function sequence counter (238) to be





58


incremented and to produce at an output (240)
thereof a next function control signal to a second
input (241) provided on said function address
generator (168), causing said function address
generator (168) to produce at said first output
(174) thereof a next function address signal
associated with a next function (183,184) to be
transmitted for the corresponding selected mode
whenever said next function address differs from
an end of sequence code, thereby causing said
function element address generator (176) to
produce at said first output (180) thereof a
function element address signal associated with at
least one function element constituting said next
function (183,184) of said selected mode whenever
data corresponding to said function next element
address differs from an end of function code,
thereby causing said function memory (181) to
produce at said first output (199) thereof a
composite digital modulation signal comprising
modulation and control data corresponding to said
function element address signal associated with at
least one function element constituting said next
function (183,184) of said selected mode, thereby
causing said driver (216) to transmit a
corresponding digital modulation signal containing
modulation data through said digital modulation
signal output (218) and to cause said driver (216)
to transmit corresponding control signals for said
oscillator (72) and harmonic generator (22)
respectively through said first and second control
outputs (219,220), said function address generator
(168) producing an end of sequence signal at a
second output (243) thereof whenever said next
function corresponds to said end of sequence, said
second output (243) being connected to a second




59


input (247) provided on said function sequence
counter (238) for resetting said sequence counter
(238) after completion of the transmission of a
last function of said function sequence
corresponding to said selected mode;

a reference clock signal generating
means (248) having an output (249) sending a
reference clock signal respectively to a second
input (250) provided on said function timer (202),
to a third input (253) provided on said function
sequence counter (238) and to a third input (256)
provided on said function element address
generator.

29. A carrier frequency modulating system as
claimed in claim 26 or 27 or 28, wherein said
sequences (32) further comprises a digital to
analog converter (161) receiving said digital
modulation signals for producing corresponding
modulation signals.

30. A carrier frequency modulating system as
claimed in claim 26 or 27 or 28, further
comprising a second bandpass filter means (150)
having an input connected to the output of said
modulator (46) to attenuate frequencies adjacent
said carrier frequency thereby producing a single
frequency modulated carrier frequency signal.

31. A carrier frequency modulating system as
claimed in claims 26, further comprising antenna
means (78) coupled to the output (76) of said
modulator, to transmit said modulated carrier
frequency signal.



60

32. A carrier frequency modulating system as
claimed in claims 27 or 28, further comprising
antenna means (78) coupled to the output of said
modulator, to transmit said modulated carrier
frequency signal.

33. A carrier frequency modulating system as
claimed in claim 31, wherein said modulation
information associated with said function elements
further comprise modulated signal level control
data, said system further comprising a variable
attenuator (74) having a first input (73)
connected to the output (76) of said modulator
(46) for coupling said modulator output (76) to
said antenna means (78) and a second output (77)
coupled to a second control output means (160)
provided on said buffer (210), said buffer (210
producing at said second control output means
(160) thereof corresponding modulated signal level
digital control signals for said variable
atenuator (74).

34. A carrier frequency modulating system as
claimed in claim 33, wherein said sequencer (32)
further comprises a digital to analog converter
(163) coupling said variable attenuator second
input (77) to said buffer second control output
(160), said digital to analog converter (163)
producing corresponding modulated signal level
analog control signals for said variable
attenuator (74).

35. A carrier frequency.modulating system as
claimed in claim 32, wherein said modulation
information associated with said function elements
further comprise modulated signal level control



61

data, said composite digital modulation signals
further comprises said modulated signal level
control data, said system further comprising a
variable attenuator (74) having a first input
(73) connected to the output (76) of said
modulator (46) for coupling said modulator output
(76) to said antenna means (78) and a second input
(77) coupled to a third control output (160)
provided on said buffer (210), said buffer (210)
producing at said third control output (160)
thereof corresponding modulated signal level
digital control signals for said variable
attenuator (74).

36. A carrier frequency modulating system as
claimed in claim 35, wherein said sequences (32)
further comprises a digital to analog converter
(163), coupling said variable attenuator second
input (77) to said buffer third control output
(160), said digital to analog converter (163)
producing corresponding modulated signal level
analog control signals for said variable
attenuator (74).

37. A carrier frequency modulating system as
claimed in claim 31, wherein said system is a
microwave landing system receiver testing system,
said modulation signal comprises at least one
phase modulation signal portion (68) and at least
one amplitude modulation signal portion (68),
said modulated carrier frequency signal comprising
respectively at least one phase modulated carrier
frequency portion and at least one amplitude
modulated carrier frequency portion.



62

38. A carrier frequency modulating system as
claimed in claim 32, wherein said system is a
microwave landing system receiver testing system,
said modulation signal comprising at least one
phase modulation signal portion (68) and at least
one amplitude modulating signal portion (68'),
said modulated carrier frequency signal comprising
respectively at least one phase modulated carrier
protion and at least one amplitude modulated
carrier frequency portion.

39. A carrier frequency modulating system as
claimed in claim 26 or 27 or 28, wherein said
reference clock signal means (248) has an input
connected to the output of said oscillator (72).

40. A carrier frequency modulating system as
claimed in claim 34, wherein said system is a
microwave landing system receiver testing system,
said modulation signal comprising at least one
phase modulation signal portion (68) and at least
one amplitude modulation signal portion (68),
said modulated carrier frequency signal comprising
respectively at least one phase modulated carrier
frequency portion.

41. A carrier frequency modulating system as
claimed in claim 36, whrein said sytem is a
microwave landing system receiver testing system,
said modulation signal comprising at least one
phase modulation signal portion (68) and at least
one amplitude modulation signal portion (68),
said modulated carrier frequency signal comprising
respectively at least one phase modulated carrier
frequency portion.



63

42. A method of modulating a carrier
frequency comprising the steps of:
i) producing a carrier frequency
signal;
ii) producing a modulation signal
comprising:
a plurality of modulation signal
portions separated by at least one
null, each said
modulation signal portion having
a corresponding time length;
iii) modulating said carrier frequency
signal according to said plurality
of modulation signal portions; and
iv) interrupting said step i) instead
of modulating said at least one
null modulation signal portion
during said corresponding time
length.

43. A method for modulating a carrier
frequency as claimed in claim 42, wherein said
step i) comprises the steps of:
a) producing a first signal at a
first frequency;
b) multiplying said first signal to
produce a second signal at a
second frequency said second
frequency being higher than
said first frequency;
c) using said second signal to
produce a third signal comprising
a plurality of harmonic
frequencies, said frequencies
higher than said second frequency;
d) filtering said harmonic



64

frequencies to select
a substantially narrow frequency
band centered at a single harmonic
frequency from said thereby
producing a corresponding
carrier frequency signal.

44. A method for modulating a carrier
frequency as claimed in claim 43, further
comprising the steps of:
v) filtering said carrier frequency
signal for attenuating frequencies
adjacent said single harmonic
frequency thereby producing a
single frequency modulated carrier
frequency signal.

45. A method for modulating a carrier
frequency as claimed in claim 42 or 43, further
comprising the steps of:
v) transmitting said modulating
signal through an antenna.



A single figure which represents the drawing illustrating the invention.

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Admin Status

Title Date
(86) PCT Filing Date 1994-06-17
(87) PCT Publication Date 1995-01-05
(85) National Entry 1995-12-15
Examination Requested 1998-11-09
(45) Issued 2003-12-16
Expired 2014-06-17

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Filing $0.00 1995-12-15
Maintenance Fee - Application - New Act 2 1996-06-17 $100.00 1996-05-29
Registration of Documents $0.00 1996-09-26
Maintenance Fee - Application - New Act 3 1997-06-17 $100.00 1997-06-04
Maintenance Fee - Application - New Act 4 1998-06-17 $100.00 1998-06-11
Request for Examination $400.00 1998-11-09
Maintenance Fee - Application - New Act 5 1999-06-17 $150.00 1999-05-26
Maintenance Fee - Application - New Act 6 2000-06-19 $150.00 2000-05-19
Maintenance Fee - Application - New Act 7 2001-06-18 $150.00 2001-05-18
Maintenance Fee - Application - New Act 8 2002-06-17 $150.00 2002-05-29
Maintenance Fee - Application - New Act 9 2003-06-17 $150.00 2003-04-25
Final $300.00 2003-09-25
Maintenance Fee - Patent - New Act 10 2004-06-17 $250.00 2004-05-27
Maintenance Fee - Patent - New Act 11 2005-06-17 $250.00 2005-06-13
Maintenance Fee - Patent - New Act 12 2006-06-19 $250.00 2006-05-23
Maintenance Fee - Patent - New Act 13 2007-06-18 $250.00 2007-05-31
Maintenance Fee - Patent - New Act 14 2008-06-17 $250.00 2008-05-22
Maintenance Fee - Patent - New Act 15 2009-06-17 $450.00 2009-05-04
Maintenance Fee - Patent - New Act 16 2010-06-17 $450.00 2010-05-04
Maintenance Fee - Patent - New Act 17 2011-06-17 $450.00 2011-05-24
Maintenance Fee - Patent - New Act 18 2012-06-18 $450.00 2012-05-30
Maintenance Fee - Patent - New Act 19 2013-06-17 $450.00 2013-05-10

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Abstract 1995-01-05 1 65
Claims 1995-01-05 30 1,274
Claims 2002-07-22 30 1,282
Claims 2002-07-23 30 1,279
Claims 2003-01-15 30 1,284
Cover Page 1996-04-18 1 19
Cover Page 2003-11-13 1 56
Description 1995-01-05 34 1,517
Description 2003-03-25 34 1,525
Description 2003-01-15 34 1,524
Drawings 1995-01-05 10 226
Drawings 2003-01-15 10 228
Prosecution-Amendment 2003-03-25 2 80
Prosecution-Amendment 2003-02-24 1 20
Prosecution-Amendment 2003-01-15 10 392
Prosecution-Amendment 2002-11-05 2 37
Prosecution-Amendment 2002-07-23 4 169
Prosecution-Amendment 2002-07-22 4 177
Prosecution-Amendment 2002-01-21 2 49
Prosecution-Amendment 1999-06-29 1 35
Prosecution-Amendment 1998-11-09 1 37
Representative Drawing 2003-12-15 1 11
Representative Drawing 2003-05-09 1 11
Representative Drawing 1998-07-20 1 10