CA2005755A1 - Direct microwave modulation and demodulation device - Google Patents
Direct microwave modulation and demodulation deviceInfo
- Publication number
- CA2005755A1 CA2005755A1 CA002005755A CA2005755A CA2005755A1 CA 2005755 A1 CA2005755 A1 CA 2005755A1 CA 002005755 A CA002005755 A CA 002005755A CA 2005755 A CA2005755 A CA 2005755A CA 2005755 A1 CA2005755 A1 CA 2005755A1
- Authority
- CA
- Canada
- Prior art keywords
- phase
- controlled
- signals
- signal
- oscillator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D1/00—Demodulation of amplitude-modulated oscillations
- H03D1/22—Homodyne or synchrodyne circuits
- H03D1/2245—Homodyne or synchrodyne circuits using two quadrature channels
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B2201/00—Aspects of oscillators relating to varying the frequency of the oscillations
- H03B2201/02—Varying the frequency of the oscillations by electronic means
- H03B2201/0208—Varying the frequency of the oscillations by electronic means the means being an element with a variable capacitance, e.g. capacitance diode
Abstract
ABSTRACT
DIRECT MIRCOWAVE MODULATION AND
DEMODULATION DEVICE.
A microwave circuit intended for either direct modulation or direct demodulation of a microwave link communications signal is characterized in that the local oscillator (8) is incorporated in the circuit. The local oscillator supplies two signals that are in phase opposition at 180 degrees. Each signal is sent to a phase shifter. The first phase shifter (9) supplies two signals that are in quadrature, at 0 and 90 degrees. The second phase shifter supplies two signals in quadrature at 180 and 270 degrees. The 0 and 180 degree signals are sent to a first mixer (2), while the 90 and 270 degree signals are sent to a second mixer (3).
Figure 3.
DIRECT MIRCOWAVE MODULATION AND
DEMODULATION DEVICE.
A microwave circuit intended for either direct modulation or direct demodulation of a microwave link communications signal is characterized in that the local oscillator (8) is incorporated in the circuit. The local oscillator supplies two signals that are in phase opposition at 180 degrees. Each signal is sent to a phase shifter. The first phase shifter (9) supplies two signals that are in quadrature, at 0 and 90 degrees. The second phase shifter supplies two signals in quadrature at 180 and 270 degrees. The 0 and 180 degree signals are sent to a first mixer (2), while the 90 and 270 degree signals are sent to a second mixer (3).
Figure 3.
Description
~S75~i D I~EC 1 ~1ILi~'UI~lA~E 1~10~UL~TI~!I~I f~l\ll~
~E~IODULhTlOl;~i ~EvlCi_ E;~Ck~ OUhl~ OF rH~ INvEhil ION
l. Fleld of the lnventiQn The present invention reiates tQ a cilrec t micrQwaYe modulaltlon and den~odulatlon device. The devlce is ue,iclned to be in the form o f an integrated circuit and is ~ar~;icularly intencied tor data processing in ~he fieid o~ microwave link communications~
Since ~he circuits used for ciirec~ modulation and ~modul~tion are ~irtually iCientical e~,~cel~t for minor de~ails, the presen t inventian shall be e:~plained with reference to a demadulator tor -the sake o~ clarity. ~ietails i~hat are specific to ~ mociLIlator shall be given ~here necessary.
~ . ~escription o~ the FriDr ~rt Cl~ssical circui~ desi~ns for diqital microwave link communications rec ~ivers alwalys include circui~s op~ratinq at intermediate tre~uencies. These intermeJiate frequency circuit~
carry out ~he preampiitication1 til~ering and ampllfi~ation ~i~h autQmatic gain con~rol ~GC) necessary to provide a conerent i, ionstant amplitucle slgnal tD the de~w~ulator.
The principle of direct modLIlation~ which is ~nown 1n the art~ consis~s in tr~nsposin~ the interrnediate trequency operations to a ba~e band ~n~ regeneratin~ the mo~ulated carrier in the demodLllation stage~ 50mpared with dassical 5 aFFroache~, ~lrect modulation obYiates the need ~or a numDer of circuits~ Lncludin~ . d~ couplers, ~f~ degree phase shitters~
~ ~ol~age-controlled osclllator, a low-noise ~GC amplitier~ and mi~.~ers.
'7~i5 In prior ar~ dire-t demodulal;lon~ a local osclliatot elivers a sin~le signal that supplies two phase shiftet stages.
fi~ st pha~e shifter accordlngly produces an in-phase signal F
iie~rees~ and a quadrature signal Q ~4 degrees~. In a second stage within the r~ r~ a second phase shif tet cQnverts the in-phase signal into two signals that ~re l~ and l~C~ de~rees out of phase~ wnile ~ third phase shifter~ conYerts the quadrature si~nal into two signal~ that are ~o and ?7l:~ de~ree~ out of Fl~se.
SOA prior art derl~odulators are gS~nerally in the form of hybrid cireuits in whlch Phase shifts are ot~tained by means o~ delay lines having YariOUs propa~ation rnodes:
microstrip linesq slotted lin~s, coplanar lines.
If monolithic gallium arsenide inte~rated circuit technology i5 U sed~ the len~th of the ~elay line ~ecomes prohit~itive, and it is the~ efore nece 5ai~y to turn to other designs~ e.g. employing locali7ed ele~nents.
S ~F~Y OF THE Il~ ENTIOhl The present in~lention teaches a different rec iYer front end ~hat is never~hel~ss functional~y equivalent. The local oscillator ~OL) produces two voltages that are e~r~actly in phase oppo~ition~ Each component is then divided in qua~rature prior to keing used for mixing. In this solution~ the ~
degree Rhase shift is generated ~y the looal osciLl~tor itself and ~nly two ~ degree ~;hif ts need be implemented on the integr alted cit cuit~ as opposed to th~ ee in a classioal :le~ n ~onoe ~C~ degrees followe~ y twice 18~:J de~reesi.
The inte~rated circuit ir;corporatin~ the abo~e novel demodulator with the law-noise amplifier forms a recei~er Z~ i5 clrcui t havlng a reduced numt!er of componen ts~ ccort lingly9 l t can produced wi th a higher yleld~
Furthermore, the s tucture accorrlint~ the oresent invention c~n alst~ be used for modulatot s ln transmitter circui ts.
rlore specil ically~ the Fresen~ inventiDn concerns a t~evice tor direct modulation or demodulation of microwaY~s, sai~ device beint~ comorisei of first and second mi~ers that deliver (in demt~dula tion~ or receive lin modul~tion~ respectively an in--phase sit~nal and ~ quairature sign~l, said first mi~.~er beinrt controlled by two signals whose phase an~les are ~J and degrees respectively~ said second mi~er t~eint~ controiled by two siqnaLls whose phasoa ant~les are qt~ and ~71:~ de~rees r esFectively, the tour signals being delivered by first and second ohase shif ters, wherein s~id device further compt-ises a ~folt~sge contrQlled local oscillator that su~plies fit-st and second sl4na,1s in phasD opposit1on~ ~;ald first si~nal having~ a t:J
de.3ree phase angle and beint! supplied to said first phase shifter~ and said second signal having a l8(:J deoree pha~;e opposition and belng supplied to said second phase shifter~
EkTEF DES~ TION OF THE I~F~t~tWIN~iS
The pr~ent invention shall be better understQod and i~s at~vantages sh2.11 t1 come clearer upon reading ~he tolloP~lng descriFtion ~f an embo~:iiment wlth reference to the apRended dr2.wings in which:
-- Fi~ure 1 is a oloc~ di~ ram o1 a pr ior at t de~nodul~tQr;
-- Figure 2 is ~ wirin~ d1~ram of a prior art demodul~tor;
-- Figure .~. is a block diagram of a demodula tor accor.iing to the present invention;
5~7~5 - Figure 4 is a wirlng dlacJr~m o~ a recelYer accordin~ to the ~nvention;
- Figure 5 i5 a circuit dlagram D-f the oscil1ator supplying two si~nal~ in quadrature, according to the pre~ent invention;
- Figure ~ is a circuit diaqram of a phase shifter prDdLIclng two si~nals in quadrature9 accordin~ tn the invention~
- Figure 7 is a circuit dia~ram of a signal input di~ider for a demodula~or according the invention;
- Figure ~ is a circuit diagram of an output com~iner for a 11~ moJulator accQr~ing to the invention;
- Fig~lre ~ is a circuit diagram of the lo~-noise A~C amplifier.
~ESC~IPTIO~ OF THE FREFE~RE~ E~ODI~ENTS
The novelty of the present invention can be ~e~ter understoad throu~h a coMparison with a classic~l circuit~ ~lnce _ the invention shall be e:~plained in terms o~ a de~a~ulator~ the i:3 prior art of fi~ure 1 also relate~ to a demodulatot-.
The lattet- forms p~r~ of a dat~ processing chain in which the mo~ul~tion method used is of the vectorial type~ i~e.
in which the carrier and its quadrature component are linearly ~i mo~ulated. ~ccordingly, the single si~nal from th~ loca1 os~illatQr ~LO~ is divided into two components ln qu~drature b~tween the two in-phase ~ and quadrature ~ channels. ~~he mi~<ers in e~ch ot the two channels can be either single~ double or ~uadru~le ~ypes~ In direct modulation7 the nee~ tor ~alanced __ structures calls for the introduction nf ~ ~ to 1~ de~ree phase shift b~tween e~ch local oscill~tor diodey in tne case o-f diode mixer.
~ receiver 1~ront end ~or vectorially modulated signal~;
therefore carries out a first l~--~0 de~ree phase shif~ on the 2~St7~S
OL siqnal, and then a ~ degree phase shi-f t on each of the mixers~ Thl, ha~ the effect of producin4 the the four Qh~ses , 4~ nd ~7i:) degt~ee~ - on the OL si~nal~
ln fi~ure 1~ ~he input ~ilgnal v~t~ is applied -50 a ', 5 divider I alld f~d to ~wo frixer~, respectively in phase F and ln quadr~ture ~ Z and ~;. Demoduiatinn i5 c~rried ~u t by a voltage controlled osclllator tvu-O~ ~hat i5 teedback con~rolled i~y a micro~trip and ~ dielectric resonator. The sin~le ~utput from the vOO is sent to a first phase shi~ter 5 that produces l~i a u degree phase signal and the ~C~ degree quadrature signal~
The ~:j degree phase sign2.1 is sent to a second phase shifter ~ thal; ~upplies the i:~ degree Dhase ~ignal ~vF.1~t~i and the 12t:~ d~ree phase opposition ~i~n~l tvF~2tt~. These t~o si~nals ~Lre sent ts the same ml.~er ~ Df the in-phase cnannel.
1-5 In a symmetrie manner, the 9C~ ~e4ree qua~r~sture si~nal is sent to a third pha~e shifter 7 that suppiie~ the ~n and 27~ degree siqnals sent to the common mi.~er 3 of the quadrature channel.
In the above demsdui~torl the input signal v~ti = ~
2l~ sin tc-~"t ~ O (t~) is ~i~fided ~et~een the tWD mixers as follows:
v~;l it~ sin t ~"t + ~ ttii; and ~ S~' it~ = ~Q sln t ~ot + i$1 tt~i, where ~ ~t~ is the modulation ~onveyed by the carrier WQ~
For a modulatlon with 4 ,ohase states~ ~he ,modulalGion ~,~ is e~spres:,ed as:
~p (t.) = ~4 + ~ where ~ o,~
Tho si~nal supplied by the Yoltage controlled oscillator is expressed as:
~ co(ti = ~ sin ~ Qt + 0 ~, e~nd e~ter ~oth typQ~ o~
21:)05~7S5 phase shif t ~ and ~, nr JZ12~ ~he four compDnents become:
VF 1 ~ t ) ~ si n ~ l~) o t ~ ~ ~1 VF~2 ~t~ = E:F~2 sin ~ tj) ot ~
VQ, ~t~ sin i (~` ot ~ t ~i:
~E~IODULhTlOl;~i ~EvlCi_ E;~Ck~ OUhl~ OF rH~ INvEhil ION
l. Fleld of the lnventiQn The present invention reiates tQ a cilrec t micrQwaYe modulaltlon and den~odulatlon device. The devlce is ue,iclned to be in the form o f an integrated circuit and is ~ar~;icularly intencied tor data processing in ~he fieid o~ microwave link communications~
Since ~he circuits used for ciirec~ modulation and ~modul~tion are ~irtually iCientical e~,~cel~t for minor de~ails, the presen t inventian shall be e:~plained with reference to a demadulator tor -the sake o~ clarity. ~ietails i~hat are specific to ~ mociLIlator shall be given ~here necessary.
~ . ~escription o~ the FriDr ~rt Cl~ssical circui~ desi~ns for diqital microwave link communications rec ~ivers alwalys include circui~s op~ratinq at intermediate tre~uencies. These intermeJiate frequency circuit~
carry out ~he preampiitication1 til~ering and ampllfi~ation ~i~h autQmatic gain con~rol ~GC) necessary to provide a conerent i, ionstant amplitucle slgnal tD the de~w~ulator.
The principle of direct modLIlation~ which is ~nown 1n the art~ consis~s in tr~nsposin~ the interrnediate trequency operations to a ba~e band ~n~ regeneratin~ the mo~ulated carrier in the demodLllation stage~ 50mpared with dassical 5 aFFroache~, ~lrect modulation obYiates the need ~or a numDer of circuits~ Lncludin~ . d~ couplers, ~f~ degree phase shitters~
~ ~ol~age-controlled osclllator, a low-noise ~GC amplitier~ and mi~.~ers.
'7~i5 In prior ar~ dire-t demodulal;lon~ a local osclliatot elivers a sin~le signal that supplies two phase shiftet stages.
fi~ st pha~e shifter accordlngly produces an in-phase signal F
iie~rees~ and a quadrature signal Q ~4 degrees~. In a second stage within the r~ r~ a second phase shif tet cQnverts the in-phase signal into two signals that ~re l~ and l~C~ de~rees out of phase~ wnile ~ third phase shifter~ conYerts the quadrature si~nal into two signal~ that are ~o and ?7l:~ de~ree~ out of Fl~se.
SOA prior art derl~odulators are gS~nerally in the form of hybrid cireuits in whlch Phase shifts are ot~tained by means o~ delay lines having YariOUs propa~ation rnodes:
microstrip linesq slotted lin~s, coplanar lines.
If monolithic gallium arsenide inte~rated circuit technology i5 U sed~ the len~th of the ~elay line ~ecomes prohit~itive, and it is the~ efore nece 5ai~y to turn to other designs~ e.g. employing locali7ed ele~nents.
S ~F~Y OF THE Il~ ENTIOhl The present in~lention teaches a different rec iYer front end ~hat is never~hel~ss functional~y equivalent. The local oscillator ~OL) produces two voltages that are e~r~actly in phase oppo~ition~ Each component is then divided in qua~rature prior to keing used for mixing. In this solution~ the ~
degree Rhase shift is generated ~y the looal osciLl~tor itself and ~nly two ~ degree ~;hif ts need be implemented on the integr alted cit cuit~ as opposed to th~ ee in a classioal :le~ n ~onoe ~C~ degrees followe~ y twice 18~:J de~reesi.
The inte~rated circuit ir;corporatin~ the abo~e novel demodulator with the law-noise amplifier forms a recei~er Z~ i5 clrcui t havlng a reduced numt!er of componen ts~ ccort lingly9 l t can produced wi th a higher yleld~
Furthermore, the s tucture accorrlint~ the oresent invention c~n alst~ be used for modulatot s ln transmitter circui ts.
rlore specil ically~ the Fresen~ inventiDn concerns a t~evice tor direct modulation or demodulation of microwaY~s, sai~ device beint~ comorisei of first and second mi~ers that deliver (in demt~dula tion~ or receive lin modul~tion~ respectively an in--phase sit~nal and ~ quairature sign~l, said first mi~.~er beinrt controlled by two signals whose phase an~les are ~J and degrees respectively~ said second mi~er t~eint~ controiled by two siqnaLls whose phasoa ant~les are qt~ and ~71:~ de~rees r esFectively, the tour signals being delivered by first and second ohase shif ters, wherein s~id device further compt-ises a ~folt~sge contrQlled local oscillator that su~plies fit-st and second sl4na,1s in phasD opposit1on~ ~;ald first si~nal having~ a t:J
de.3ree phase angle and beint! supplied to said first phase shifter~ and said second signal having a l8(:J deoree pha~;e opposition and belng supplied to said second phase shifter~
EkTEF DES~ TION OF THE I~F~t~tWIN~iS
The pr~ent invention shall be better understQod and i~s at~vantages sh2.11 t1 come clearer upon reading ~he tolloP~lng descriFtion ~f an embo~:iiment wlth reference to the apRended dr2.wings in which:
-- Fi~ure 1 is a oloc~ di~ ram o1 a pr ior at t de~nodul~tQr;
-- Figure 2 is ~ wirin~ d1~ram of a prior art demodul~tor;
-- Figure .~. is a block diagram of a demodula tor accor.iing to the present invention;
5~7~5 - Figure 4 is a wirlng dlacJr~m o~ a recelYer accordin~ to the ~nvention;
- Figure 5 i5 a circuit dlagram D-f the oscil1ator supplying two si~nal~ in quadrature, according to the pre~ent invention;
- Figure ~ is a circuit diaqram of a phase shifter prDdLIclng two si~nals in quadrature9 accordin~ tn the invention~
- Figure 7 is a circuit dia~ram of a signal input di~ider for a demodula~or according the invention;
- Figure ~ is a circuit diagram of an output com~iner for a 11~ moJulator accQr~ing to the invention;
- Fig~lre ~ is a circuit diagram of the lo~-noise A~C amplifier.
~ESC~IPTIO~ OF THE FREFE~RE~ E~ODI~ENTS
The novelty of the present invention can be ~e~ter understoad throu~h a coMparison with a classic~l circuit~ ~lnce _ the invention shall be e:~plained in terms o~ a de~a~ulator~ the i:3 prior art of fi~ure 1 also relate~ to a demodulatot-.
The lattet- forms p~r~ of a dat~ processing chain in which the mo~ul~tion method used is of the vectorial type~ i~e.
in which the carrier and its quadrature component are linearly ~i mo~ulated. ~ccordingly, the single si~nal from th~ loca1 os~illatQr ~LO~ is divided into two components ln qu~drature b~tween the two in-phase ~ and quadrature ~ channels. ~~he mi~<ers in e~ch ot the two channels can be either single~ double or ~uadru~le ~ypes~ In direct modulation7 the nee~ tor ~alanced __ structures calls for the introduction nf ~ ~ to 1~ de~ree phase shift b~tween e~ch local oscill~tor diodey in tne case o-f diode mixer.
~ receiver 1~ront end ~or vectorially modulated signal~;
therefore carries out a first l~--~0 de~ree phase shif~ on the 2~St7~S
OL siqnal, and then a ~ degree phase shi-f t on each of the mixers~ Thl, ha~ the effect of producin4 the the four Qh~ses , 4~ nd ~7i:) degt~ee~ - on the OL si~nal~
ln fi~ure 1~ ~he input ~ilgnal v~t~ is applied -50 a ', 5 divider I alld f~d to ~wo frixer~, respectively in phase F and ln quadr~ture ~ Z and ~;. Demoduiatinn i5 c~rried ~u t by a voltage controlled osclllator tvu-O~ ~hat i5 teedback con~rolled i~y a micro~trip and ~ dielectric resonator. The sin~le ~utput from the vOO is sent to a first phase shi~ter 5 that produces l~i a u degree phase signal and the ~C~ degree quadrature signal~
The ~:j degree phase sign2.1 is sent to a second phase shifter ~ thal; ~upplies the i:~ degree Dhase ~ignal ~vF.1~t~i and the 12t:~ d~ree phase opposition ~i~n~l tvF~2tt~. These t~o si~nals ~Lre sent ts the same ml.~er ~ Df the in-phase cnannel.
1-5 In a symmetrie manner, the 9C~ ~e4ree qua~r~sture si~nal is sent to a third pha~e shifter 7 that suppiie~ the ~n and 27~ degree siqnals sent to the common mi.~er 3 of the quadrature channel.
In the above demsdui~torl the input signal v~ti = ~
2l~ sin tc-~"t ~ O (t~) is ~i~fided ~et~een the tWD mixers as follows:
v~;l it~ sin t ~"t + ~ ttii; and ~ S~' it~ = ~Q sln t ~ot + i$1 tt~i, where ~ ~t~ is the modulation ~onveyed by the carrier WQ~
For a modulatlon with 4 ,ohase states~ ~he ,modulalGion ~,~ is e~spres:,ed as:
~p (t.) = ~4 + ~ where ~ o,~
Tho si~nal supplied by the Yoltage controlled oscillator is expressed as:
~ co(ti = ~ sin ~ Qt + 0 ~, e~nd e~ter ~oth typQ~ o~
21:)05~7S5 phase shif t ~ and ~, nr JZ12~ ~he four compDnents become:
VF 1 ~ t ) ~ si n ~ l~) o t ~ ~ ~1 VF~2 ~t~ = E:F~2 sin ~ tj) ot ~
VQ, ~t~ sin i (~` ot ~ t ~i:
3 VQ2 ~tj = ~Q~? sin ~ ~d Qt ~ ~ ~ ff t~
~fter filtering, the ol~tput frum ~nl.er F becQmes:
P ~t~ = ~ cos ~ it~; ~nd the output fr3m ml ~er ~;
b2comæs:
Q ~tj = C~ sin ~ ~t~ ~ where ~ and ~ are coer1icients.
regeneratDr reconstitutes the s~ream of transmitted d~ta on the basis ol the above two wave trains l t) and ~
f i~re r~ show~ a physical layout of a rE~?ceiver comprislng the direct demoJulatiQn device of figu~e 1.
3 receiver is a demodulator to which are added a low--nQlse empiifler wlth ~iC ~nd ~ ~C~O. ~iuch a t-eceiver comprise~ three phase ~hifters 5,b~7~ whether i~ be constructed as a hybrid or as an Integrated cir}uit.
rhe d1rect demoaLllatlon devlce accordln~ to che present inventlon 15 shown in fi~Llre ~. lt is comp~ised ot only two phase sni~ters Y,lo slnce the osclllator 8 ~s lncludea the clemodu~a~3r and gens r ~t2s two l~ ~egree phase shifted signals at source. ~ha~e shifters S~ generate two ~ iegree phas2 shif ted si4nals.
~ccordin~ly~ wherea~; a prior at-t device wouid employ a ~o clegree pnase shi-f t~r 5 followe ~ y two l~w degree pha~e shltters ~7~ the pre~ent invention uses an oscillator ~3 followed by ~WQ ~0 de~ree ph~se shifters ~1l1, It follows tha t two ~u~Futs~ respectlvely at ~ and 113~:~ degrees~ o~ ~he Dhase , . . .
:. : ,:
, . . : : . ::~ . . : :
`7~S
shif~ers ~ ~ ar~ permuted~ F'hase shlfter ;~ drives one lnput at e~ch ot the two ln-phase ~nd ~uadrature ml)~et s~
F~ In a ~ymmetric mannery phase shlf~er lC/ also dt ~.es one input ~n each of the t~o mi~ers.
The ,~scllla tor ~ produces two vol ta~3s in phase oppositlon:
VCi (tj = vl sin t ~ t + ~ nd v, 2 tt~ = V2 sin i~c~ + 0 +Ir ~
The above two volt~ges themselves prodLIre two lC~ voltages in quadrature Jownstre~m of the phase shifters ~,lC~
V~L tt~ = Et~l sin (0O~ +~
VQ~ it~ sin ~ ~ ot + B + Ir ~
c,~ (t~ ;in i(,~ ~,t CQ~ it~ 2 sin t t~ .t ~ ~ +ir ~
There i~i thus obtained the four cQmponents of a ~lassical demo~ulator structure~ Accordln~ly, the same w~ve tralns F':t~ ~ncl ~)itJ are ~rDduced at the demodulator ou tPUt~
The novelty ot the present strul::ture lS of inverting th~
and 18l~ de~1ree phase shif ts and bringing the l~l~ degree phase _ ~ shlft to the level of the oscilla~or where it can easily b;3 carrled out.
Fi~ure 4~ tak:en in contrast with ~igure ~, demons ~rates that the demodul~tor Oaccording to the present n~ention i~ simpler than that of the prior art, since there are only two F~hase shif ter5 ~lo. Tne description of th~ stru.ctl lre of each par t o~ the demoluOator shall show that the presen t C:lt cuit lends itseif parti~ularly to well to inte~3ration, e~pecially on gr oup III-v materials adapted to micro~aves, such ~.~ ~i~i~15~
- : , ' ' ' : :. . ; :
5i5 The balanced t~ CI degree osclllal:ar~ sho~Jn in tigure 5, lS of the push-pull type and its operation 15 p2rtially kn~n~ e.g. from French Fatent No~ 85~4 from the applicant.
~ut tne oscill~tar of the present invention has been modified with respect ~o the prior art oscillator in order to deliver two output signals in pha~e oppositlQn, as opposed to a slng31e slgnal at a doubled frequency.
hll the elem~nts appearing nn the left of the dotted line are in hy~rid technology. They comprise two microstrip 14 prDp~gation lines 11?1~ on an insul~ting substrate terminated by 5d ohm load~ hn inductor Lp connectlng the two lines puts in serles the low-frequency noi~e generators which cancel e~ch ot~er out. The two lines, which carry currents i~1 and ig?
~; tlowing in oaposlte direct1ons,~are coupled by a dielectrlc resonator 1~ connected therebetween.
~ 11 the elements appearing on the right of the dotted line are m~de in t~alhum arsenide integrated circult technology.
They first Df al~ comprise tran~ist~rs T1 ~nd T~ functloning as an oscillator and whose drain currents id~ an~ id~ are ln pha~e ~o opposlt1on~ sint-e their gate currents ig3~ 2nd i92 ~re ~l,o ln phase opposition.
h source impedance, generally designated Z5~ connects together ~he sourres of the tw~ transistors Tl and T~. The imped~nce is comprised of t~o ~aractor diodes controllet~ by respectiYe volta~3es Vzl and v ~ Pnabling the introduction of the frequency change require~ during demodulation.
The transistors T~3 and T4 function as an ~mplifler respectively loading ~ransistors Tl and T~ with impedances that are optimi~ed tor osclllation. They provide the outout level ; - ~ ,, , .:
: ,, . ~ : , :
;7~
for e~ch char~nel ~nd the isolation with respect to the clrcuit appllcation tload impeoance~.
Tr an~i~tDrS r~. and T4 respectivel.y dellYer the ln-phase si~nal ~cl {t~ and ~he phase opposition signal ~c~ it~, 5 which are sent to the ~hase shil ters ~ and 10.
In the above oscill~tor, the signals ar-e in phase opposltion by virtue of the struCtLlre~ so long as the two channels are electrically and geometrically symme~rical. These criteria are well satisfied by the impl ementation in a gaili~
10 ~rsenide inte4rated clrcult.
The two phase shif ters 4,1~ are of -the same type and their outputs ~eliver two slgnals in ~uadra ture. iqore sp~cifically~ one ot th~3 si~3nals has a 45 ~legree phase ~dvance, while the nther has a 45 degree phase delay; ~u t the two 15~ sil;nals do indeed have a ~C1 degree rela tive ph~se shif t. The clrcult dia~ram for one of the phase shlf~ers i5 ~hown in tigure ~
F~t the input E, the signal -- Vcl (tj9 for instance - is divided into two in a l~lilkinson type -trllcture with locali~ed ~o elements Cll~ L11, Ll:~, F~11y L111, L11 .
In a first channel~ shown in the top portion of fi~ure ~, 5he circuit defined by the elements L1~;, L14~ Tll? F~
and Cl~ forms a vari~ble phase--shif t cell controlled by the gate voltage of an unbiased ~ranslstor T11. The re4ulating voltage ~ l acting on the g~te of T11 increases or decreases the capacit~nce of the latter, ~hlch 15 connected ln parallel wi~h C;1~.. The p5 ase shlft for the above channei lg f1nally obtalned oy adiu~tin~ the circult elements L14~ C1-4 and L15.
The si~nal YF'1 ~t~ output from this channel lS phase . - .
,, - . '::: : : . -: : ' : :
.. . ~ ~: :, : :: :
;, ~ : : ::, . ::: :
21)~5~
1l) shi fted by ~ 45 degree with respect to the slgnal voltaqe Vcl i t`~ at tne lnF!ut E.
In a second channel~ the circult elements L~ 1?, T1~ l- and ~15 form a variabie attenuator whlch ~lse~ two unbiased tr~nsistors. The attenuation lS controlled t~y the adjustment v~ltage VF~ app~ied bet~een F~ and L15. q se~ond clrcult, defineci by elements ~ ;1~, L17 and C17~ allowc ~o obtaln an ou~put signal v~ t~ that 15 pha~e shltted by - 45 degree~1 and hence in quadrature with si~nal vFl it~ ~rom the first channel.
The equaii2ing of amplit Ide between the two channels is carried out by tr~nSiStQrs Ti2 and Tl~ an~ the Y O degree phase shitt i~; regulated by transls~or Tll? all three transistors oein~ unbiased lYdS = t~ V~
The input divider tor the clirect mol:iuiation or demo~lulation deYice can t~e of a known design. However~ there i5 shown in fi~ure 7 an original ~lesign that has been specially produced ~or the purposes ol lntegration~ and in particular Tor inte~ration on g~lliun) arsenide.
Here~ the principle involves applyin~ the signal V it~
present at the input E -- an i which must be ~iivi:led into two e~lal sign~ls -- to the single bifurca te~i gate of a transistor T ~ ha~-ing t~o ~rains. The tr~nslstor is shown on the right-han~ portion of fig ~re 7. The two ~;eparate ~irain~i ~rovidS~ the t~o output channels ~S~ it~ and ~S2 ~t~.
Ir the circuit elements are strictly identical for each chanrlel, the outp ut si~nals will have the sam~? Dhase an~
amplitude. The advantage of the above divider is that ~he use of acti~e elemen-~s ean provide a gain fnr each channel and a , . : : ::
-: ~,; ''.' ' ~ :
~o~s~
goQd isolation af the channels with respect; to the input.
Up ~o this point, the pr esent }nventlon has t~een ~escriue~ wlth r eference to a direct demodu1ato~. However, tne inventlon concerns a dlrec t modulator then the divlaer 5 ClrCLii t ol figure 7 should be replaced by a comblner CirCUlt, as ~hown in f iguiSe 8.
In the latter case, the input slgnals are signals P~t~
and bl ~t~ of figure 3? and the combiner of figur~ ~3 combines in -phase the two modulated channels output by the m1. et-s ~ ~3 lq This combinet is in fact a WilkiQs~sn type circuit which i~
identical to that lncor porated in the phase shifters s7~
The combiner is followed by an automatic gain control ampii~ication stage for transmit ting the modulated sign~i7 the amplification stage repladng ~he IQw-noise ampLifier at the 15 lnpu t for the case o~ demodulation.
~ ;eturning to a di~Sect delr;ndula~lon clevice~ fi~ur-e shows a CirCLIi t 1:iiagram ~or the low--nois , a~tomatic gain control amplifier.
The ampli~let has a three-s~age struct~re7 each stage providin~ a ~pecific func~ion. The fir ~t stage ~tr ansi~tor T~
has an input adapted for a low noise factor. The second stage ~transistor T3~ uses a dual--gate transistor, the secon~ qate ~f ~hich is biased by a voltage VF;3 that controls the gain for that stage. The last stage itransistor T3~) has a very ~ide 7~ transistor to give a very linear response to the amplifier -sin~ transi~tor T33 i~ wid S-~ it opet ates far fr om lts sa tur a tion point~
The ml~ ers 2~ are no t covered in detail. They ha~,-e nown~ al2nced type structures, and ran be construc~ed rrom ... . . . . .
: . . .
diodes or transistors.
The direct modulation or [iemodula tion cievices accordin~ tQ the present in~/ention are u~ed for processing mlcrl~wave signals~ e~g~ in line--of-sight communicatlon~; or radar.
They ~re definecl in the following claims~
2~i .
~fter filtering, the ol~tput frum ~nl.er F becQmes:
P ~t~ = ~ cos ~ it~; ~nd the output fr3m ml ~er ~;
b2comæs:
Q ~tj = C~ sin ~ ~t~ ~ where ~ and ~ are coer1icients.
regeneratDr reconstitutes the s~ream of transmitted d~ta on the basis ol the above two wave trains l t) and ~
f i~re r~ show~ a physical layout of a rE~?ceiver comprislng the direct demoJulatiQn device of figu~e 1.
3 receiver is a demodulator to which are added a low--nQlse empiifler wlth ~iC ~nd ~ ~C~O. ~iuch a t-eceiver comprise~ three phase ~hifters 5,b~7~ whether i~ be constructed as a hybrid or as an Integrated cir}uit.
rhe d1rect demoaLllatlon devlce accordln~ to che present inventlon 15 shown in fi~Llre ~. lt is comp~ised ot only two phase sni~ters Y,lo slnce the osclllator 8 ~s lncludea the clemodu~a~3r and gens r ~t2s two l~ ~egree phase shifted signals at source. ~ha~e shifters S~ generate two ~ iegree phas2 shif ted si4nals.
~ccordin~ly~ wherea~; a prior at-t device wouid employ a ~o clegree pnase shi-f t~r 5 followe ~ y two l~w degree pha~e shltters ~7~ the pre~ent invention uses an oscillator ~3 followed by ~WQ ~0 de~ree ph~se shifters ~1l1, It follows tha t two ~u~Futs~ respectlvely at ~ and 113~:~ degrees~ o~ ~he Dhase , . . .
:. : ,:
, . . : : . ::~ . . : :
`7~S
shif~ers ~ ~ ar~ permuted~ F'hase shlfter ;~ drives one lnput at e~ch ot the two ln-phase ~nd ~uadrature ml)~et s~
F~ In a ~ymmetric mannery phase shlf~er lC/ also dt ~.es one input ~n each of the t~o mi~ers.
The ,~scllla tor ~ produces two vol ta~3s in phase oppositlon:
VCi (tj = vl sin t ~ t + ~ nd v, 2 tt~ = V2 sin i~c~ + 0 +Ir ~
The above two volt~ges themselves prodLIre two lC~ voltages in quadrature Jownstre~m of the phase shifters ~,lC~
V~L tt~ = Et~l sin (0O~ +~
VQ~ it~ sin ~ ~ ot + B + Ir ~
c,~ (t~ ;in i(,~ ~,t CQ~ it~ 2 sin t t~ .t ~ ~ +ir ~
There i~i thus obtained the four cQmponents of a ~lassical demo~ulator structure~ Accordln~ly, the same w~ve tralns F':t~ ~ncl ~)itJ are ~rDduced at the demodulator ou tPUt~
The novelty ot the present strul::ture lS of inverting th~
and 18l~ de~1ree phase shif ts and bringing the l~l~ degree phase _ ~ shlft to the level of the oscilla~or where it can easily b;3 carrled out.
Fi~ure 4~ tak:en in contrast with ~igure ~, demons ~rates that the demodul~tor Oaccording to the present n~ention i~ simpler than that of the prior art, since there are only two F~hase shif ter5 ~lo. Tne description of th~ stru.ctl lre of each par t o~ the demoluOator shall show that the presen t C:lt cuit lends itseif parti~ularly to well to inte~3ration, e~pecially on gr oup III-v materials adapted to micro~aves, such ~.~ ~i~i~15~
- : , ' ' ' : :. . ; :
5i5 The balanced t~ CI degree osclllal:ar~ sho~Jn in tigure 5, lS of the push-pull type and its operation 15 p2rtially kn~n~ e.g. from French Fatent No~ 85~4 from the applicant.
~ut tne oscill~tar of the present invention has been modified with respect ~o the prior art oscillator in order to deliver two output signals in pha~e oppositlQn, as opposed to a slng31e slgnal at a doubled frequency.
hll the elem~nts appearing nn the left of the dotted line are in hy~rid technology. They comprise two microstrip 14 prDp~gation lines 11?1~ on an insul~ting substrate terminated by 5d ohm load~ hn inductor Lp connectlng the two lines puts in serles the low-frequency noi~e generators which cancel e~ch ot~er out. The two lines, which carry currents i~1 and ig?
~; tlowing in oaposlte direct1ons,~are coupled by a dielectrlc resonator 1~ connected therebetween.
~ 11 the elements appearing on the right of the dotted line are m~de in t~alhum arsenide integrated circult technology.
They first Df al~ comprise tran~ist~rs T1 ~nd T~ functloning as an oscillator and whose drain currents id~ an~ id~ are ln pha~e ~o opposlt1on~ sint-e their gate currents ig3~ 2nd i92 ~re ~l,o ln phase opposition.
h source impedance, generally designated Z5~ connects together ~he sourres of the tw~ transistors Tl and T~. The imped~nce is comprised of t~o ~aractor diodes controllet~ by respectiYe volta~3es Vzl and v ~ Pnabling the introduction of the frequency change require~ during demodulation.
The transistors T~3 and T4 function as an ~mplifler respectively loading ~ransistors Tl and T~ with impedances that are optimi~ed tor osclllation. They provide the outout level ; - ~ ,, , .:
: ,, . ~ : , :
;7~
for e~ch char~nel ~nd the isolation with respect to the clrcuit appllcation tload impeoance~.
Tr an~i~tDrS r~. and T4 respectivel.y dellYer the ln-phase si~nal ~cl {t~ and ~he phase opposition signal ~c~ it~, 5 which are sent to the ~hase shil ters ~ and 10.
In the above oscill~tor, the signals ar-e in phase opposltion by virtue of the struCtLlre~ so long as the two channels are electrically and geometrically symme~rical. These criteria are well satisfied by the impl ementation in a gaili~
10 ~rsenide inte4rated clrcult.
The two phase shif ters 4,1~ are of -the same type and their outputs ~eliver two slgnals in ~uadra ture. iqore sp~cifically~ one ot th~3 si~3nals has a 45 ~legree phase ~dvance, while the nther has a 45 degree phase delay; ~u t the two 15~ sil;nals do indeed have a ~C1 degree rela tive ph~se shif t. The clrcult dia~ram for one of the phase shlf~ers i5 ~hown in tigure ~
F~t the input E, the signal -- Vcl (tj9 for instance - is divided into two in a l~lilkinson type -trllcture with locali~ed ~o elements Cll~ L11, Ll:~, F~11y L111, L11 .
In a first channel~ shown in the top portion of fi~ure ~, 5he circuit defined by the elements L1~;, L14~ Tll? F~
and Cl~ forms a vari~ble phase--shif t cell controlled by the gate voltage of an unbiased ~ranslstor T11. The re4ulating voltage ~ l acting on the g~te of T11 increases or decreases the capacit~nce of the latter, ~hlch 15 connected ln parallel wi~h C;1~.. The p5 ase shlft for the above channei lg f1nally obtalned oy adiu~tin~ the circult elements L14~ C1-4 and L15.
The si~nal YF'1 ~t~ output from this channel lS phase . - .
,, - . '::: : : . -: : ' : :
.. . ~ ~: :, : :: :
;, ~ : : ::, . ::: :
21)~5~
1l) shi fted by ~ 45 degree with respect to the slgnal voltaqe Vcl i t`~ at tne lnF!ut E.
In a second channel~ the circult elements L~ 1?, T1~ l- and ~15 form a variabie attenuator whlch ~lse~ two unbiased tr~nsistors. The attenuation lS controlled t~y the adjustment v~ltage VF~ app~ied bet~een F~ and L15. q se~ond clrcult, defineci by elements ~ ;1~, L17 and C17~ allowc ~o obtaln an ou~put signal v~ t~ that 15 pha~e shltted by - 45 degree~1 and hence in quadrature with si~nal vFl it~ ~rom the first channel.
The equaii2ing of amplit Ide between the two channels is carried out by tr~nSiStQrs Ti2 and Tl~ an~ the Y O degree phase shitt i~; regulated by transls~or Tll? all three transistors oein~ unbiased lYdS = t~ V~
The input divider tor the clirect mol:iuiation or demo~lulation deYice can t~e of a known design. However~ there i5 shown in fi~ure 7 an original ~lesign that has been specially produced ~or the purposes ol lntegration~ and in particular Tor inte~ration on g~lliun) arsenide.
Here~ the principle involves applyin~ the signal V it~
present at the input E -- an i which must be ~iivi:led into two e~lal sign~ls -- to the single bifurca te~i gate of a transistor T ~ ha~-ing t~o ~rains. The tr~nslstor is shown on the right-han~ portion of fig ~re 7. The two ~;eparate ~irain~i ~rovidS~ the t~o output channels ~S~ it~ and ~S2 ~t~.
Ir the circuit elements are strictly identical for each chanrlel, the outp ut si~nals will have the sam~? Dhase an~
amplitude. The advantage of the above divider is that ~he use of acti~e elemen-~s ean provide a gain fnr each channel and a , . : : ::
-: ~,; ''.' ' ~ :
~o~s~
goQd isolation af the channels with respect; to the input.
Up ~o this point, the pr esent }nventlon has t~een ~escriue~ wlth r eference to a direct demodu1ato~. However, tne inventlon concerns a dlrec t modulator then the divlaer 5 ClrCLii t ol figure 7 should be replaced by a comblner CirCUlt, as ~hown in f iguiSe 8.
In the latter case, the input slgnals are signals P~t~
and bl ~t~ of figure 3? and the combiner of figur~ ~3 combines in -phase the two modulated channels output by the m1. et-s ~ ~3 lq This combinet is in fact a WilkiQs~sn type circuit which i~
identical to that lncor porated in the phase shifters s7~
The combiner is followed by an automatic gain control ampii~ication stage for transmit ting the modulated sign~i7 the amplification stage repladng ~he IQw-noise ampLifier at the 15 lnpu t for the case o~ demodulation.
~ ;eturning to a di~Sect delr;ndula~lon clevice~ fi~ur-e shows a CirCLIi t 1:iiagram ~or the low--nois , a~tomatic gain control amplifier.
The ampli~let has a three-s~age struct~re7 each stage providin~ a ~pecific func~ion. The fir ~t stage ~tr ansi~tor T~
has an input adapted for a low noise factor. The second stage ~transistor T3~ uses a dual--gate transistor, the secon~ qate ~f ~hich is biased by a voltage VF;3 that controls the gain for that stage. The last stage itransistor T3~) has a very ~ide 7~ transistor to give a very linear response to the amplifier -sin~ transi~tor T33 i~ wid S-~ it opet ates far fr om lts sa tur a tion point~
The ml~ ers 2~ are no t covered in detail. They ha~,-e nown~ al2nced type structures, and ran be construc~ed rrom ... . . . . .
: . . .
diodes or transistors.
The direct modulation or [iemodula tion cievices accordin~ tQ the present in~/ention are u~ed for processing mlcrl~wave signals~ e~g~ in line--of-sight communicatlon~; or radar.
They ~re definecl in the following claims~
2~i .
Claims (6)
1. a device for direct modulation or demodulation of microwaves, said device being comprised of first and second mixers that deliver (in demodulation) or receive (in modulation) respectively an in-phase signal and a quadrature signal, said first mixer being controlled by two signals whose phase angles are 0 and 180 degrees respectively, said second mixer being controlled by two signals whose phase angles are 90 and 270 degrees respectively, the four signals being delivered by first and second phase shifters, wherein said device further comprises a voltage controlled local oscillator that supplies first and second signals in phase opposition, said first signal having a 0 degree phase angle and being supplied to said first phase shifter, and said second signal having a 180 degree phase opposition and being supplied to said second phase shifter.
2. A device as claimed in claim 1, wherein said first and second phase shifters each deliver two signals that are in quadrature, said two signals delivered by said first phase shifter, respectively having phase angles of 0 and 90 degrees, being supplied to said first and second mixers respectively.
3. A device as claimed in claim 1 wherein said voltage controlled oscillator is comprised of first and second field effect oscillator transistors that are connected in parallel, and wherein: - the sources are interconnected via a variable impedance comprised of two varactors controlled by two voltages: - the gates are controlled by a circuit comprised of two microstrip lines coupled to a single dielectric resonator.
the current flow in said microstrip lines being in mutually opposite directions; - the drain cut-rents are accordingly in phase opposition; said oscillator further comprising two additional amplifier transistors, one per output channel, whose gates are controlled by the drain currents of said first and second oscillator transistors.
the current flow in said microstrip lines being in mutually opposite directions; - the drain cut-rents are accordingly in phase opposition; said oscillator further comprising two additional amplifier transistors, one per output channel, whose gates are controlled by the drain currents of said first and second oscillator transistors.
4. A device as claimed in claim 1, wherein each of said two phase shifters is comprised of:
- a Wilkinson type structure comprised of localised elements, having an input. receiving a signal from said oscillator, said structure dividing said oscillator signal into two signals sent respectively to:
- a first in-phase channel comprising a variable phase shift circuit controlled by an unbiased transistor controlled by an regulating voltage, and a fixed phase shift circuit; and - a second channel in quadrature comprising a variable attenuator circuit controlled by two unbiased transistors, controlled by a regulating voltage, and a fixed phase shift circuit, said two regulating voltages serving to adjust the balance the amplitudes and the 90 degree phase shift angle of said two channels.
- a Wilkinson type structure comprised of localised elements, having an input. receiving a signal from said oscillator, said structure dividing said oscillator signal into two signals sent respectively to:
- a first in-phase channel comprising a variable phase shift circuit controlled by an unbiased transistor controlled by an regulating voltage, and a fixed phase shift circuit; and - a second channel in quadrature comprising a variable attenuator circuit controlled by two unbiased transistors, controlled by a regulating voltage, and a fixed phase shift circuit, said two regulating voltages serving to adjust the balance the amplitudes and the 90 degree phase shift angle of said two channels.
5. A device as claimed in claim 1, wherein, in the case of said device being a demodulator, the, ? divider is comprised of a field effect transistor having a single, bifurcated gate and two separate drains, the source thereof being grounded.
6. A device as claimed in claim 1, wherein, in the case of said device being a modulator, said combiner is a Wilkinson type structure having first and second inputs receiving the outputs from said first and second mixers, and an output delivering a modulated signal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8816802A FR2640829B1 (en) | 1988-12-20 | 1988-12-20 | DEVICE FOR DIRECT MICROWAVE MODULATION OR DEMODULATION |
| FR8816802 | 1988-12-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2005755A1 true CA2005755A1 (en) | 1990-06-20 |
Family
ID=9373159
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002005755A Abandoned CA2005755A1 (en) | 1988-12-20 | 1989-12-18 | Direct microwave modulation and demodulation device |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5122765A (en) |
| EP (1) | EP0375497A1 (en) |
| JP (1) | JPH02194753A (en) |
| CA (1) | CA2005755A1 (en) |
| DK (1) | DK641389A (en) |
| FR (1) | FR2640829B1 (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE9400950U1 (en) * | 1994-01-20 | 1995-08-24 | Selectronic Vertriebs Gmbh | Device for detecting living bodies and their use |
| US6091940A (en) | 1998-10-21 | 2000-07-18 | Parkervision, Inc. | Method and system for frequency up-conversion |
| US6061551A (en) | 1998-10-21 | 2000-05-09 | Parkervision, Inc. | Method and system for down-converting electromagnetic signals |
| US7515896B1 (en) | 1998-10-21 | 2009-04-07 | Parkervision, Inc. | Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships |
| US6694128B1 (en) | 1998-08-18 | 2004-02-17 | Parkervision, Inc. | Frequency synthesizer using universal frequency translation technology |
| US6542722B1 (en) | 1998-10-21 | 2003-04-01 | Parkervision, Inc. | Method and system for frequency up-conversion with variety of transmitter configurations |
| US6370371B1 (en) | 1998-10-21 | 2002-04-09 | Parkervision, Inc. | Applications of universal frequency translation |
| US7039372B1 (en) | 1998-10-21 | 2006-05-02 | Parkervision, Inc. | Method and system for frequency up-conversion with modulation embodiments |
| US6560301B1 (en) | 1998-10-21 | 2003-05-06 | Parkervision, Inc. | Integrated frequency translation and selectivity with a variety of filter embodiments |
| US7236754B2 (en) | 1999-08-23 | 2007-06-26 | Parkervision, Inc. | Method and system for frequency up-conversion |
| US6049706A (en) | 1998-10-21 | 2000-04-11 | Parkervision, Inc. | Integrated frequency translation and selectivity |
| US6061555A (en) | 1998-10-21 | 2000-05-09 | Parkervision, Inc. | Method and system for ensuring reception of a communications signal |
| US6813485B2 (en) | 1998-10-21 | 2004-11-02 | Parkervision, Inc. | Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same |
| US6704558B1 (en) | 1999-01-22 | 2004-03-09 | Parkervision, Inc. | Image-reject down-converter and embodiments thereof, such as the family radio service |
| US6704549B1 (en) | 1999-03-03 | 2004-03-09 | Parkvision, Inc. | Multi-mode, multi-band communication system |
| US6879817B1 (en) | 1999-04-16 | 2005-04-12 | Parkervision, Inc. | DC offset, re-radiation, and I/Q solutions using universal frequency translation technology |
| US6853690B1 (en) | 1999-04-16 | 2005-02-08 | Parkervision, Inc. | Method, system and apparatus for balanced frequency up-conversion of a baseband signal and 4-phase receiver and transceiver embodiments |
| US7693230B2 (en) | 1999-04-16 | 2010-04-06 | Parkervision, Inc. | Apparatus and method of differential IQ frequency up-conversion |
| US7110444B1 (en) | 1999-08-04 | 2006-09-19 | Parkervision, Inc. | Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations |
| US7065162B1 (en) | 1999-04-16 | 2006-06-20 | Parkervision, Inc. | Method and system for down-converting an electromagnetic signal, and transforms for same |
| US8295406B1 (en) | 1999-08-04 | 2012-10-23 | Parkervision, Inc. | Universal platform module for a plurality of communication protocols |
| US7010286B2 (en) | 2000-04-14 | 2006-03-07 | Parkervision, Inc. | Apparatus, system, and method for down-converting and up-converting electromagnetic signals |
| US7454453B2 (en) | 2000-11-14 | 2008-11-18 | Parkervision, Inc. | Methods, systems, and computer program products for parallel correlation and applications thereof |
| US7072427B2 (en) | 2001-11-09 | 2006-07-04 | Parkervision, Inc. | Method and apparatus for reducing DC offsets in a communication system |
| US7460584B2 (en) | 2002-07-18 | 2008-12-02 | Parkervision, Inc. | Networking methods and systems |
| US7379883B2 (en) | 2002-07-18 | 2008-05-27 | Parkervision, Inc. | Networking methods and systems |
| US7323950B2 (en) * | 2004-08-12 | 2008-01-29 | Hoover Lowell R | Balanced hybrid coupler network |
| JP4620982B2 (en) * | 2004-08-13 | 2011-01-26 | 富士通株式会社 | Oscillator circuit |
| US7760038B2 (en) * | 2005-12-07 | 2010-07-20 | Electronics And Telecommunications Research Institute | Voltage controlled oscillator capable of tuning negative resistance |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS608628B2 (en) * | 1976-07-05 | 1985-03-04 | ヤマハ株式会社 | Semiconductor integrated circuit device |
| FR2600215B1 (en) | 1986-06-13 | 1988-08-19 | Thomson Csf | DOUBLE FREQUENCY OSCILLATOR, OPERATING IN MICROWAVE |
-
1988
- 1988-12-20 FR FR8816802A patent/FR2640829B1/en not_active Expired - Fee Related
-
1989
- 1989-12-08 EP EP89403405A patent/EP0375497A1/en not_active Ceased
- 1989-12-12 US US07/448,992 patent/US5122765A/en not_active Expired - Fee Related
- 1989-12-14 JP JP1322785A patent/JPH02194753A/en active Pending
- 1989-12-18 CA CA002005755A patent/CA2005755A1/en not_active Abandoned
- 1989-12-18 DK DK641389A patent/DK641389A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| DK641389A (en) | 1990-06-21 |
| EP0375497A1 (en) | 1990-06-27 |
| FR2640829B1 (en) | 1991-02-08 |
| JPH02194753A (en) | 1990-08-01 |
| US5122765A (en) | 1992-06-16 |
| FR2640829A1 (en) | 1990-06-22 |
| DK641389D0 (en) | 1989-12-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |