USRE42043E1 - Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion - Google Patents
Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion Download PDFInfo
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- USRE42043E1 USRE42043E1 US11/318,388 US31838805A USRE42043E US RE42043 E1 USRE42043 E1 US RE42043E1 US 31838805 A US31838805 A US 31838805A US RE42043 E USRE42043 E US RE42043E
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
- H04L27/20—Modulator circuits; Transmitter circuits
- H04L27/2032—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner
- H04L27/2053—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases
- H04L27/206—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases using a pair of orthogonal carriers, e.g. quadrature carriers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/38—Angle modulation by converting amplitude modulation to angle modulation
- H03C3/40—Angle modulation by converting amplitude modulation to angle modulation using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated
- H03C3/403—Angle modulation by converting amplitude modulation to angle modulation using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated using two quadrature frequency conversion stages in cascade
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
- H03D7/16—Multiple-frequency-changing
- H03D7/165—Multiple-frequency-changing at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature
- H03D7/166—Multiple-frequency-changing at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature using two or more quadrature frequency translation stages
Definitions
- the field of the invention is that of transmitting signals by a frequency channel.
- transmission of a signal by a frequency channel more and more often calls upon digital modulation, the main advantage of which is that it permits the use of signal processing algorithms.
- the purpose of these algorithms is to increase the strength of the signal to be transmitted relative to the propagation channel.
- the invention relates to a radiofrequency transmitter of the type supplied by two signals (or components) in baseband and in quadrature i(t) and q(t), which are images of two binary streams representing a piece of information to be transmitted.
- i(t) and q(t) are images of two binary streams representing a piece of information to be transmitted.
- radiofrequency transmitter In the state of the technology, different types of radiofrequency transmitter are known, each based on a distinct architecture. The most widely known are the radiofrequency transmitter with frequency transposition, the radiofrequency transmitter with direct conversion and the radiofrequency transmitter with a phase locked loop. Their respective disadvantages will now be discussed.
- the radiofrequency transmitter with frequency transposition which permits transposition to an intermediate frequency FI, requires the use of selective pass band filters, so as to reject the image frequency of the wanted signal to be transmitted.
- This first type of radiofrequency transmitter provides good performance, thanks to frequency transposition into the digital domain.
- the requirement to use high performance filters restricts its degree of integration onto silicon.
- the radiofrequency transmitter with direct conversion has the most simple architecture and offers a high degree of integration. Its weak point is its high sensitivity to the performance of the elements that make it up. In particular, it is recommended that any leakage from the conversion oscillator via the mixer be avoided or that provision is made for perfect quadrature of the sine and cosine signals. These imperatives are often difficult to keep to.
- the radiofrequency transmitter with a phase locked loop offers numerous advantages, such as the ability to do away with RF filters thanks to the pass band characteristic of the phase locked loop or PLL.
- the requirement to have the signals strictly in quadrature is also avoided. Nevertheless, these results are only possible if the voltage controlled oscillator or VCO included in the PLL provides high performance. This is not the case with integrated VCOs. Consequently, the PLL radiofrequency transmitter does not enable a high level of integration to be provided.
- a particular objective of the invention is to remedy these various disadvantages of the state of the technology.
- one of the objectives of this invention is to provide a radiofrequency transmitter providing good precision and offering a very high degree of integration on silicon.
- Another objective of the invention is to provide such a radiofrequency transmitter that has very low sensitivity to the imperfections in the elements that make it up.
- Another objective of the invention is to provide such a radiofrequency transmitter that enables one to avoid degradation of the wanted signal.
- a complementary objective of the invention is to provide such a radiofrequency transmitter which is simple and is not any more complex than the known architectures.
- Another objective of the invention is to provide such a radiofrequency transmitter that allows one to generate a resultant signal that has an image frequency that is sufficiently weak to be able to be suppressed by a filter with relaxed constraints (this filter thus being capable of being integrated).
- another objective of the invention is to provide a radiofrequency transmitter that does not give an image frequency, the image frequency at the output being completely attenuated, in an automatic fashion, by a self-calibrating system that compensates for imperfections both in gain and in phase.
- a radiofrequency transmitter of the type supplied with two signals in baseband and in quadrature, i(nT) and q(nT), which are images from two binary streams representing information to be transmitted, the radiofrequency transmitter comprising:
- this invention proposes an original architecture for a radiofrequency transmitter that combines the architectures with direct conversion and with frequency transposition, and which provides, in addition, means of digital processing, which provide preprocessing that permits attenuation at the output of the image frequency introduced by the means of transposition into an intermediate frequency.
- this new architecture combines the main advantage of the radiofrequency transmitter with direct conversion (no image frequency) with that of the radiofrequency transmitter with frequency transposition (no degradation of the wanted signal), while at the same time avoiding their disadvantages (sensitivity to imperfections, high performance filter).
- this invention operates perfectly if the two channels of the direct conversion means have the same gain and if the sines and cosines supplied by the oscillator included in the direct conversion means do not suffer from poor quadrature forming.
- the first frequency transposition and the signal processing are carried out in the digital domain, which enables one to benefit from the precision and the high degree of integration (on silicon for example).
- the radiofrequency transmitter according to the invention has a high degree of integration (for example, on silicon) and advantageously can even be entirely produced in the form of an integrated circuit.
- the means of direct conversion are known for their high degree of silicon integration.
- the level of integration of the means of transposition into an intermediate frequency can be relatively high since it is not necessary to use high performance filters.
- the digital processing means can be reduced to an assembly of elements currently used in integrated systems on silicon, and notably in transmitters with frequency transposition. This assembly of elements comprises, for example, a Numerically Controlled Oscillator or NCO and linear operators (multipliers and adders).
- said radiofrequency transmitter additionally comprises means of digitally compensating for imperfections in gain and in phase in said means of direct conversion.
- the performance of the radiofrequency transmitter according to the invention is optimized and the resulting transmitted signal has characteristics close to the ideal case. Thanks to this self-calibrating technique of image annulment, the errors introduced by the analog part (that is to say the means of direct conversion) sensitive to the imperfections, are compensated for in the digital domain.
- said analog/digital conversion means have a working frequency substantially identical to the working frequency of the digital/analog conversion means in said means of direct conversion.
- said means of digital compensation are included in said integrated circuit.
- the radiofrequency transmitter according to this invention can be entirely integrated, for example on silicon.
- FIG. 1 shows a general diagram of a first embodiment of a radiofrequency transmitter according to this invention with “simple” image annulment
- FIG. 2 shows a general diagram of a second embodiment of a radiofrequency transmitter according to this invention with “self-calibrating” image annulment.
- the invention relates to a radiofrequency transmitter of the type supplied with two digital signals in baseband and in quadrature i(nT) and q(nT), which are images of two binary streams representing information to be transmitted.
- T is the sample period.
- m(t) i(t) ⁇ cos( ⁇ t) ⁇ q(t) ⁇ sin( ⁇ t).
- a first embodiment of a radiofrequency transmitter according to this invention will now be described making reference to FIG. 1 .
- the radiofrequency transmitter comprises means 1 of transposition into an intermediate frequency and of digital processing and means 2 of direct conversion.
- the means 1 of transposition into an intermediate frequency and of digital processing generate two signals m 1 (t) and m 2 (t) at an intermediate frequency ⁇ 0 and in quadrature. They comprise:
- the means 2 of direct conversion generate a resultant signal m(t). They comprise:
- This filter 17 may possibly also be included in the integrated circuit in which form the radiofrequency transmitter is produced.
- the principle consists of generating two signals m 1 (t) and m 2 (t) made up of the two channels in quadrature i(t) and q(t).
- m 1 (t) i(t) ⁇ cos( ⁇ 0 t) ⁇ q(t) ⁇ sin( ⁇ 0 t)
- m 2 (t) ⁇ i(t) ⁇ sin( ⁇ 0 t) ⁇ q(t) ⁇ cos( ⁇ 0 t) (2)
- the means 2 of direct conversion transpose the two signals around the carrier frequency ⁇ 1 by multiplying them by sin( ⁇ 1 t+ ⁇ ) and cos ( ⁇ 1 t+ ⁇ ).
- m(t) g 1 ⁇ m 1 (t) ⁇ cos( ⁇ 1 t+ ⁇ 1 )+g 2 ⁇ m 2 (t) ⁇ sin( ⁇ 1 t+ ⁇ 2 ) (5)
- the resultant signal m(t) is therefore constituted by:
- Equation (11) shows that the imperfections in gain and in phase generate a parasite component in ⁇ 2 of power sufficiently low to be easily filtered. Contrary to this, the imperfections have very little influence on the quality of the wanted signal.
- the C/I of the wanted signal (power of the signal/power of the interference at frequency ⁇ 2 ) is 68 dBc, instead of 28 dBc for an architecture with traditional direct conversion.
- the power level of the interference present at the image frequency ⁇ ⁇ 2 is about 28 dB below the wanted signal while it would be 25 times higher with a traditional frequency transposition structure.
- this original system offers the following advantages:
- a second embodiment of a radiofrequency transmitter according to this invention will now be described with reference to FIG. 2 .
- This second embodiment differs from the first embodiment (described above with reference to FIG. 1 ) in that it additionally comprises means 10 , 11 of digitally compensating for imperfections in gain ⁇ g and in phase ⁇ of the direct conversion means 2 .
- These compensation means themselves comprise means 10 of estimating the imperfections ⁇ g and ⁇ , and means 11 of applying a correction to the two signals m 1 (t) and m 2 (t) in a way that generates two corrected signals m 1c (t) and m 2c (t).
- the means 10 of estimating the imperfections comprise:
- the means 1 of transposition into intermediate frequency and of digital processing, the means 15 of calculating the imperfections and the means 11 of applying a correction to the two signals m 1 (t) and m 2 (t) can be included in one and the same digital signal processor (or DSP) 16 .
- this second embodiment of the radiofrequency transmitter can be broken down into three successive phases, namely;
- the resultant signal m(t) is multiplied by the frequency ⁇ 1 of the conversion oscillator 7 (the latter is included in the direct conversion means 2 ). Hence m(t) is transposed to a lower fixed frequency, before analog/digital conversion.
- m 3 ′ ⁇ ( t ) g 3 ⁇ m ⁇ ( t ) ⁇ cos ⁇ ( w 1 ⁇ t + ⁇ - ⁇ ⁇ ⁇ ⁇ 2 )
- m′ 3 (t) ⁇ g ⁇ cos ⁇ ( ⁇ ⁇ ⁇ ⁇ 2 ) ⁇ ⁇ i ⁇ ( t ) 2 ⁇ [ cos ⁇ ( ⁇ 0 ⁇ t + ⁇ ⁇ ⁇ ⁇ 2 ) + cos ⁇ ( 2 ⁇ ⁇ 1 ⁇ t + ⁇ 0 ⁇ t + 2 ⁇ ⁇ - ⁇ ⁇ ⁇ 2 ) ] - q ⁇ ( t ) 2 ⁇ [ sin ⁇ ( ⁇ 0 ⁇ t + ⁇ ⁇ ⁇ ⁇ 2 ) + sin ⁇ ( 2 ⁇ ⁇ 1 ⁇ t + ⁇ 0 ⁇ t + 2 ⁇ ⁇ - ⁇ ⁇ ⁇ 2 ) ] ⁇ - ⁇ ⁇ ⁇ ⁇ g 2 ⁇ sin ⁇ ( ⁇ ⁇ ⁇ ⁇ g 2 ⁇ sin ⁇ ( ⁇ ⁇ ⁇ ⁇ g 2 ⁇ sin ⁇ ( ⁇
- m c ⁇ ( t ) m 1 ⁇ c ⁇ ( t ) ⁇ ( g - ⁇ ⁇ ⁇ g 2 ) ⁇ cos ⁇ ( ⁇ 1 ⁇ t + ⁇ - ⁇ ⁇ ⁇ 2 ) + ⁇ m 2 ⁇ c ⁇ ( t ) ⁇ ( g + ⁇ ⁇ ⁇ g 2 ) ⁇ sin ⁇ ( ⁇ 1 ⁇ t + ⁇ + ⁇ ⁇ ⁇ ⁇ 2 ) ( 25 )
- m 1c (t) and m 2c (t) are the two channels corrected for gain and phase:
- m 1 ⁇ c ⁇ ( t ) 1 ( 1 + ⁇ ⁇ ⁇ g 2 ⁇ ) ⁇ [ i ⁇ ( t ) ⁇ cos ⁇ ( ⁇ 0 ⁇
- m 1 ⁇ c ⁇ ( t ) ( 1 + ⁇ ⁇ ⁇ g 2 ⁇ g ) ⁇ [ i ⁇ ( t ) ⁇ cos ⁇ ( ⁇ 0 ⁇ t - ⁇ ⁇ ⁇ ⁇ 2 ) - q ⁇ ( t ) ⁇ sin ⁇ ( ⁇ 0 ⁇ t - ⁇ ⁇ ⁇ ⁇ 2 ) ]
- m 2 ⁇ c ⁇ ( t ) - ( 1 + ⁇ ⁇ ⁇ g 2 ⁇ ) ⁇ [ i ⁇ ( t ) ⁇ sin ⁇ ( ⁇ 0 ⁇ t + ⁇ ⁇ ⁇ ⁇ 2 ) + q ⁇ ( t ) ⁇ sin ⁇ ( ⁇ 0 ⁇ t + ⁇ ⁇ ⁇ ⁇ 2 ) ]
- the algorithms for calculating ⁇ g and ⁇ have been successfully simulated: the error is compensated after 5 iterations at the most, according to the orders of magnitude of ⁇ g and ⁇ (up to 10% and 8° respectively) and with an error ranging up to 12% on the value of g 3 .
- the signal processing functions are carried out in the digital domain so as to exploit the precision and the high degree of integration on silicon.
- the analog/digital converter (CAN) 14 is, for example of the “delta-sigma pass band” type, whose working frequency is preferably identical to that of the two digital/analog converters 5 1 and 5 2 .
- the analog high stop filter 13 has relaxed constraints: a filter of order 2 is sufficient in most cases.
- the radiofrequency transmitter according to the invention provides relatively low complexity compared with the remainder of the transmission chain and has the advantage of being able to be completely integrated on silicon.
Abstract
Description
-
- m(t)=i(t)·cos(ωt)−q(t)·sin(ωt), where ω (=2πf) is the transmission frequency of the signal (also called the carrier frequency).
-
- means of transposition into an intermediate frequency and of digital processing, that provide a first transposition into the digital domain, at an intermediate frequency ω0, for said base band signals, and generating, by combination, two signals at the intermediate frequency and in quadrature;
- means of direct conversion, providing a second transposition into the analog domain, after multiplication by a frequency ω1, followed by a summation, of said two signals at the intermediate frequency and in quadrature, in a way that generates a resultant signal which is finally modulated around a frequency ω2, where ω2=ω0+ω1.
m(t)=i(t)·cos(ωt)−q(t)·sin(ωt).
where ω (=2πf), the frequency of transmission of the signal (also called the carrier frequency).
-
- a numerically controlled oscillator NCO (not shown) at an intermediate frequency ω0, supplying the following signals: cos(ω0·nT) and sin(ω0·nT);
- four multipliers 3 1 to 3 4; and
- two adders 4 1 to 4 2.
m1(nT)=i(nT)·cos(ω0·nT)−q(nT)·sin(ω0·nT)
m2(nT)=−i(nT)·sin(ω0·nT)−q(nT)·cos(ω0·nT)
-
- on each of the two channels in quadrature, a digital/analog converter (CNA) 5 1, 5 2 and a high-
stop filter - a
conversion oscillator 7 at a transmission frequency ω1, supplying the following signals: cos(ω1·t) and sin(ω1·t); - two multipliers 8 1 and 8 2;
- one adder 9.
- on each of the two channels in quadrature, a digital/analog converter (CNA) 5 1, 5 2 and a high-
m(t)=g1·m1(t)·cos(ω1t+θ1)+g2·m2(t)·sin(ω1t+θ2)
where g1 and g2 are the respective gains of the two channels in quadrature of the
m1(t)=i(t)·cos(ω0t)−q(t)·sin(ω0t)
m2(t)=−i(t)·sin(ω0t)−q(t)·cos(ω0t) (2)
where ω0(=2πf0) is the first intermediate frequency generated in the digital domain.
m(t)=m1(t)·cos(ω1t+φ)+m2(t)·sin(ω1t+φ)=i(t)·cos(ω0t+ω1t+φ)−q(t)·sin(ω0t+ω1t+φ) (3)
m(t)=i(t)·cos(ω2t+φ)−q(t)·sin(ω2t+φ) (4)
m(t)=g1·m1(t)·cos(ω1t+θ1)+g2·m2(t)·sin(ω1t+θ2) (5)
m(t)=i(t)·[g1·cos ω0t·cos(ω
1t+θ1)−g2·sin ω0t·sin(ω1t+θ2)]
−q(t)·[g1·sin ω0t·cos(ω1t+θ1)+g
2·cos ω0t·sin(ω1t+θ2)]
which means that m(t) can be expressed in the form:
-
- a wanted signal (modulated about the carrier ω2), weighted by a gain equal to
- an undesirable component, whose amplitude is of the order of
- an image in ω−2 (due to the imperfections), the power of which depends on the difference in gain Δg and in phase Δθ between the two channels.
- a wanted signal (modulated about the carrier ω2), weighted by a gain equal to
-
- an identical gain for the channels i(t) and q(t);
- negligible degradation of the wanted signal (≈Δg·Δθ/4);
- a highly attenuated image frequency which can be suppressed with a relaxed constraint filter;
- reduced complexity compared with a direct conversion transmitter thanks to signal processing being carried out in the digital domain.
-
- transposition means 12, providing a third transposition in the analog domain, by multiplication of the resultant signal m(t) by the transmission frequency ω1, in a way that generates an intermediate signal: m′3(t)=g3·m(t)·cos(ω1t+θ1), where g3 is the gain introduced by the transposition means 12, the filtering means 13 and the analog/digital A/N conversion means 14.
- a
high stop filter 13, providing filtering of the intermediate signal m′3(t) and generating an intermediate filtered signal m′(t); - an analog/digital converter (CAN) 14, enabling one to convert the intermediate filtered signal m′(t) into digital;
- means 15 of calculating imperfections in gainΔg and in phase Δθ from the digital filtered intermediate signal m′(t).
-
- recovery of the resultant transmitted signal m(t);
- calculation of the correction coefficients Δg and Δθ;
- calculation of the resultant corrected signal mc(t).
a=i(t)·i′(t)+q(t)·q′(t)
b=i(t)·q′(t)−q(t)·i′(t) (19)
1.3 CALCULATION OF THE CORRECTION COEFFICIENTS
where m1c(t) and m2c(t) are the two channels corrected for gain and phase:
-
- to the first channel: a gain equal to (1+Δg/2g) and a phase shift equal to (−Δθ/2);
- to the second channel: a gain equal to (1−Δg/2g) and a phase shift equal to (+Δθ/2).
Claims (28)
Δg=g2−g1
Δθ=θ2−θ1
mc(t)=g1·m1c(t)·cos(ω1t+θ1)+g2·m2c(t)·sin(ω1t+θ2).
m′3(t)=g3·m(t)·cos(ω1t+θ1),
m′(t)=i′(t)·cos(ω0t)−q′(t)·sin(ω0t)
Δg=2g−(4/g3)·[i′(t)+q′(t)]·[i(t)−q(t)]
Δθ=(1/g·g3)·[i(t)·q′(t)−q(t)i′(t)].
m1c(t)=(1+(Δg/2g))·[i(t)·cos(ω0t−(Δθ/2))−q(t)·sin(ω0t−(Δθ/2))]
m2c(t)=−(1−(Δg/2g))·[i(t)·sin(ω0t−(Δθ/2))−q(t)·cos(ω0t+(Δθ/2))].
m 1(t)=i(t)·cos(ω0 t)−q(t)·sin(ω0 t)
m 2(t)=−i(t)·sin(ω0 t)−q(t)·cos(ω0 t); and
m(t)=g 1 ·m 1(t)·cos(ω1 t+θ 1)+g 2 ·m 2(t)·sin(ω1 t+θ 2),
Δg=g 2 −g 1 ; and
Δθ=θ2−θ1 ; and
m c(t)=g 1 ·m 1c(t)·cos(ω1 t+θ 1)+g 2 ·m 2c(t)·sin(ω1 t+θ 2).
m′ 3(t)=g 3 ·m(t)·cos(ω1 t+θ 1),
m′(t)=i′(t)·cos(ω0 t)−q′(t)·sin(ω0 t);
Δg=2g−( 4/g 3)·[i′(t)+q′(t)]·[i(t)−q(t)]
Δθ=( 1/g·g 3)·[i(t)·q′(t)−q(t)i′(t)].
m 1c(t)=( 1+(Δg/2g))·[i(t)·cos(ω0 t−(Δθ/2 ))−q(t)·sin(ω0 t−(Δθ/2 ))]
m 2c(t)=−( 1−(Δg/2g))·[i(t)·sin(ω0 t−(Δθ/2 ))−q(t)·cos(ω0 t+(Δθ/2 ))].
m 1(t)=i(t)·cos(ω0 t)−q(t)·sin(ω0 t)
m 2(t)=−i(t)·sin(ω0 t)−q(t)·cos(ω0 t); and
m(t)=g 1 ·m 1(t)·cos(ω1 t+θ 1)+g 2 ·m 2(t)·sin(ω1 t+θ 2)
m 1(t)=i(t)·cos(ω0 t)−q(t)·sin(ω0 t)
m 2(t)=−i(t)·sin(ω0 t)−q(t)·cos(ω0 t); and
m(t)=g 1 ·m 1(t)·cos(ω1 t+θ 1)+g 2 ·m 2(t)·sin(ω1 t+θ 2)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/318,388 USRE42043E1 (en) | 1999-03-23 | 2005-12-23 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9903768A FR2791506B1 (en) | 1999-03-23 | 1999-03-23 | RADIO FREQUENCY TRANSMITTER WITH HIGH DEGREE OF INTEGRATION AND WITH IMAGE CANCELLATION, POSSIBLY SELF-CALIBRATED |
FR9903768 | 1999-03-23 | ||
US09/518,944 US6668024B1 (en) | 1999-03-23 | 2000-03-06 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
US11/318,388 USRE42043E1 (en) | 1999-03-23 | 2005-12-23 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
Related Parent Applications (1)
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US09/518,944 Reissue US6668024B1 (en) | 1999-03-23 | 2000-03-06 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
Publications (1)
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USRE42043E1 true USRE42043E1 (en) | 2011-01-18 |
Family
ID=9543657
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US09/518,944 Ceased US6668024B1 (en) | 1999-03-23 | 2000-03-06 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
US11/318,388 Expired - Fee Related USRE42043E1 (en) | 1999-03-23 | 2005-12-23 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
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US09/518,944 Ceased US6668024B1 (en) | 1999-03-23 | 2000-03-06 | Radiofrequency transmitter with a high degree of integration and possibly with self-calibrating image deletion |
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Country | Link |
---|---|
US (2) | US6668024B1 (en) |
EP (1) | EP1039628B1 (en) |
DE (1) | DE60022247T2 (en) |
FR (1) | FR2791506B1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US10756798B2 (en) * | 2016-08-04 | 2020-08-25 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and transmitter for transmit beamforming in a wireless communication system |
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WO2002051003A2 (en) * | 2000-12-18 | 2002-06-27 | Koninklijke Philips Electronics N.V. | Generating two signals having a mutual phase difference of 90° |
US7177372B2 (en) * | 2000-12-21 | 2007-02-13 | Jian Gu | Method and apparatus to remove effects of I-Q imbalances of quadrature modulators and demodulators in a multi-carrier system |
US20030003891A1 (en) * | 2001-07-02 | 2003-01-02 | Nokia Corporation | Method to improve I/Q-amplitude balance and receiver quadrature channel performance |
DE10144907A1 (en) * | 2001-09-12 | 2003-04-03 | Infineon Technologies Ag | Transmission arrangement, in particular for mobile radio |
KR100457175B1 (en) * | 2002-12-14 | 2004-11-16 | 한국전자통신연구원 | Quadrature modulation transmitter |
US7515647B2 (en) | 2003-11-28 | 2009-04-07 | Samsung Electronics Co., Ltd | Digital frequency converter |
US7647028B2 (en) * | 2005-04-06 | 2010-01-12 | Skyworks Solutions, Inc. | Internal calibration system for a radio frequency (RF) transmitter |
FR2914515B1 (en) | 2007-04-02 | 2009-07-03 | St Microelectronics Sa | CALIBRATION IN A RADIO FREQUENCY TRANSMIT MODULE |
CN102460978B (en) * | 2009-06-23 | 2015-08-12 | 诺基亚公司 | For the method for Dual channel transmission, device and radio communication equipment |
DE102010027566A1 (en) * | 2010-05-18 | 2011-11-24 | Rohde & Schwarz Gmbh & Co. Kg | Signal generator with digital intermediate frequency and digital fine tuning |
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1999
- 1999-03-23 FR FR9903768A patent/FR2791506B1/en not_active Expired - Fee Related
-
2000
- 2000-03-02 EP EP00460019A patent/EP1039628B1/en not_active Expired - Lifetime
- 2000-03-02 DE DE60022247T patent/DE60022247T2/en not_active Expired - Lifetime
- 2000-03-06 US US09/518,944 patent/US6668024B1/en not_active Ceased
-
2005
- 2005-12-23 US US11/318,388 patent/USRE42043E1/en not_active Expired - Fee Related
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Cited By (1)
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US10756798B2 (en) * | 2016-08-04 | 2020-08-25 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and transmitter for transmit beamforming in a wireless communication system |
Also Published As
Publication number | Publication date |
---|---|
DE60022247T2 (en) | 2006-07-20 |
DE60022247D1 (en) | 2005-10-06 |
EP1039628B1 (en) | 2005-08-31 |
FR2791506A1 (en) | 2000-09-29 |
EP1039628A1 (en) | 2000-09-27 |
US6668024B1 (en) | 2003-12-23 |
FR2791506B1 (en) | 2001-06-22 |
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