Author: claimsbot

1. A compound of Formula XI:
wherein:
K1, K2 and K4 are hetero atoms independently selected from the group consisting of N, O, S, Se, Te, and CH;
K3 is N;
S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 are independently selected from the group consisting of H, aryl, phenyl, cycloalkyl, alkyl, alkenyl, alkynyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxyl, sulfonyl, imido, amido, and carbamoyl;
and wherein from one to four of S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 may optionally be independently selected linking groups Q, wherein said linking groups Q are of the formula:
wherein:
n is from 0 to 10;
R3 may be present or absent;
R1, R2, and R3 are each independently selected from the group consisting of ethene, ethyne, aryl, and heteroaryl groups, which aryl and heteroaryl groups may be unsubstituted or substituted one or more times with H, aryl, phenyl, cycloalkyl, alkyl, alkenyl, alkynyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxyl, sulfonyl, imido, amido, and carbamoyl;
Y is a protected or unprotected reactive substituent selected from the group consisting of hydroxy, thio, seleno, telluro, ester, carboxylic acid, boronic acid, phenol, silane, sulfonic acid, phosphonic acid, alkyithiol, formyl, halo, alkenyl, alkynyl, haloalkyl, alkyl phosphonate, alkyl sulfonate, alkyl carboxylate, and alkyl boronate groups; and
Z is selected from the group consisting of halo, alkoxy, and acyloxy.
2. The compound according to claim 1, wherein S1 and S5 are independently selected trans-substituted linking groups Q.
3. The compound according to claim 1, wherein S2 and S6 are independently selected trans-substituted linking groups Q.
4. The compound according to claim 1, wherein K1, and K2, and K4 are independently selected from the group consisting of N, O, S, and CH.
5. The compound according to claim 1, wherein K1, K2 and K4 are all N.
6. The compound according to claim 1, wherein S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 are all alkyl.
7. The compound of claim 1 having the formula 7a:

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A computed tomography apparatus for imaging an object, the computed tomography apparatus comprising:
an imaging region for receiving the object to be imaged,
a radiation source for generating modulated radiation traversing the object in the imaging region,
a detector for generating detection values depending on the radiation after having traversed the object,
a moving unit for moving the radiation source and the object relative to each other, while generating the detection values, for generating detection values depending on radiation having traversed the object in different directions,
a weight providing unit for providing modulation weights for weighting the detection values depending on the modulation of the radiation,
a reconstruction unit for reconstructing an image of the object, wherein the reconstruction unit is adapted to weight the detection values based on the provided modulation weights and to reconstruct the image of the object from the weighted detection values.
2. The computed tomography apparatus as defined in claim 1, wherein the computed tomography apparatus comprises an object table on which the object is to be located, wherein the moving unit is adapted to rotate the radiation source around the object table and wherein the radiation source is adapted such that the intensity of the radiation is lower above the object table than below the object table.
3. The computed tomography apparatus as defined in claim 1, wherein the weight providing unit is adapted to determine a noise variance of a detection value and to provide the modulation weight for the detection value depending on the inverse noise variance.
4. The computed tomography apparatus as defined in claim 1, wherein the radiation source is adapted to modulate the intensity of the generated radiation, wherein the weight providing unit is adapted to determine a modulation weight for a detection value depending on the modulated intensity of the generated radiation.
5. The computed tomography apparatus as defined in claim 1, wherein the radiation source is adapted to generate the modulated radiation such that the modulated radiation is conical and wherein the weight providing unit is further adapted to provide coneweights for weighting the detection values depending on a cone angle of the radiation on which the respective detection values depend.
6. The computed tomography apparatus as defined in claim 1, wherein the radiation source is adapted to generate the modulated radiation such that the modulated radiation is divergent, wherein the computed tomography apparatus further comprises a rebinning unit for rebinning the detection values being generated depending on the divergent radiation thereby forming rebinned projections, wherein the weight providing unit is adapted to:
determine intermediate modulation weights for at least a part of the detection values of a rebinned projection, wherein the intermediate modulation weights depend on the modulation of the radiation,
determine for the rebinned projection a mean modulation weight being an average of the intermediate modulation weights for the at least a part of the rebinned detection values of the rebinned projection, wherein the mean modulation weight is the provided modulation weight for the detection values of the rebinned projection.
7. The computed tomography apparatus as defined in claim 6, wherein the moving unit is adapted to rotate the radiation source and the imaging region relative to each other around a rotational axis, while generating the detection values, wherein the at least a part of the rebinned detection values of the rebinned projection are rebinned detection values arranged along a line being perpendicular to the rotational axis.
8. The computed tomography apparatus as defined in claim 6, wherein the computed tomography apparatus further comprises a region of interest selection unit for selecting a region of interest to be reconstructed, wherein the at least a part of the rebinned detection values is a part of the rebinned detection values which has been generated depending on radiation having traversed the selected region of interest.
9. The computed tomography apparatus as defined in claim 6, wherein the weight providing unit is further adapted to determine the mean modulation weight by weightedly averaging the intermediate modulation weights for the at least a part of the rebinned detection values, wherein the intermediate modulation weights are weighted during averaging such that intermediate modulation weights of rebinned detection values which depend on radiation having traversed the region of interest more centrally receive a larger weight than intermediate modulation weights of rebinned detection values which depend on radiation having traversed the region of interest more peripherally.
10. The computed tomography apparatus as defined in claim 8, wherein the weight providing unit is further adapted to determine the mean modulation weight by weightedly averaging the intermediate modulation weights of the at least a part of the rebinned detection values, wherein the intermediate modulation weights are weighted during averaging depending on the size of an intersection region of the region of interest and the radiation on which the respective rebinned detection value depends.
11. An imaging apparatus for generating an image of an object, the imaging apparatus being adapted to process detection values generated by an acquisition unit comprising:
an imaging region for receiving the object to be imaged,
a radiation source for generating modulated radiation traversing the object in the imaging region,
a detector for generating detection values depending on the radiation after having traversed the object,
a moving unit for moving the radiation source and the object relative to each other, while generating the detection values, for generating detection values depending on radiation having traversed the object in different directions, wherein the imaging apparatus comprises:
a weight providing unit for providing modulation weights for weighting the detection values depending on the modulation of the radiation,
a reconstruction unit for reconstructing an image of the object, wherein the reconstruction unit is adapted to weight the detection values based on the provided modulation weights and to reconstruct the image of the object from the weighted detection values.
12. A computed tomography method for imaging an object, the computed tomography method comprising following steps:
generating modulated radiation traversing an object in an imaging region by a radiation source,
generating detection values depending on the radiation after having traversed the object by a detector,
moving the radiation source and the object relative to each other, while generating the detection values, for generating detection values depending on radiation having traversed the object in different directions by a moving unit,
providing weights for the detection values depending on the modulation of the radiation by a weight providing unit,
weighting the detection values based on the provided modulation weights by a reconstruction unit,
reconstructing an image of the object from the weight detection values by the reconstruction unit.
13. An imaging method for generating an image of an object, the imaging method being adapted to process detection values generated by an acquisition unit comprising:
an imaging region for receiving the object to be imaged,
a radiation source for generating modulated radiation traversing the object in the imaging region,
a detector for generating detection values depending on the radiation after having traversed the object,
a moving unit for moving the radiation source and the object relative to each other, while generating the detection values, for generating detection values depending on radiation having traversed the object in different directions, wherein the imaging method comprises following steps:
providing weights for the detection values depending on the modulation of the radiation by a weight providing unit,
weighting the detection values based on the provided modulation weights by a reconstruction unit,
reconstructing an image of the object from the weight detection values by the reconstruction unit.
14. A computed tomography computer program, the computed tomography computer program comprising program code means for causing a computed tomography apparatus as defined in claim 1 to carry out the steps of the computed tomography method, when the computed tomography computer program is run on a computer controlling the computed tomography apparatus.
15. An imaging computer program, the imaging computer program comprising program code means for causing an imaging apparatus as defined in claim 11 to carry out the steps of the imaging method, when the imaging computer program is run on a computer controlling the imaging apparatus.

What is claimed is:

1. A system for an auto-ignition of gasoline internal combustion engine comprising:
a cylinder;
a piston disposed within said cylinder for reciprocating motion to define a combustion chamber;
intake means for admitting fresh air into said cylinder;
a fuel injector directly communicating with said combustion chamber;
exhaust means for discharging exhaust gas resulting from combustion within said cylinder; and
a control unit adjusting opening and closing timings of said intake means and opening and closing timings of said exhaust means such that said piston reciprocates within said cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase, wherein said intake means and exhaust means being closed to retain exhaust gas within said cylinder during said exhaust gas retaining phase,
said control unit providing a first start time of a first fuel injection by said fuel injector during said exhaust gas retaining phase and a second start time of a second fuel injection by said fuel injector during said compression phase,
said control unit determining a portion of total fuel quantity and the remainder of said total fuel quantity,
said control unit determining a first fuel injection control signal indicative of said portion of said total fuel quantity and applying said first fuel injection control signal to said fuel injector at said first start time to control fuel quantity injected for said first fuel injection,
said control unit determining a second fuel injection control signal indicative of the remainder of said total fuel quantity and applying said second fuel injection control signal at said second start time to control fuel quantity injected for said second fuel injection,
said remainder of said total fuel quantity being proportional to the engine load of the internal combustion engine.
2. The system as claimed in claim 1, wherein said portion of said determined total fuel quantity is substantially invariable with variation of the engine load of the internal combustion engine.
3. The system as claimed in claim 1, wherein said portion of said total fuel quantity is inversely proportional to the engine load of said internal combustion engine.
4. The system as claimed in claim 1, wherein said control unit provides said first start time of said first fuel injection during movement of said piston from the initiation of said exhaust gas retaining phase to the top dead center position during said exhaust gas retaining phase.
5. The system as claimed in claim 1, wherein said control unit advances said second start time of said second fuel injection as the engine load of said internal combustion engine increases.
6. The system as claimed in claim 1, wherein said control unit increases fuel quantity for said first fuel injection as the engine speed of said internal combustion engine increases.
7. The system as claimed in claim 1, wherein said control unit advances said start first time of said first fuel injection as the engine speed of the internal combustion engine increases.
8. The system as claimed in claim 1, wherein said control unit advances said second start time of said second fuel injection as the engine speed of said internal combustion engine increases.
9. A system for an auto-ignition of gasoline internal combustion engine comprising:
a cylinder;
a piston disposed within said cylinder for reciprocating motion to define a combustion chamber;
intake means for admitting fresh air into said cylinder;
a fuel injector directly communicating with said combustion chamber;
exhaust means for discharging exhaust gas resulting from combustion within said cylinder; and
a control unit selecting one of a gasoline reform auto-ignition combustion mode and an auto-ignition combustion mode in response to magnitude of an operating parameter indicative of one of the engine load and the engine speed of the internal combustion engine,
said control unit being operative during selection of said gasoline reform auto-ignition combustion mode to adjust opening and closing timings of said intake means and opening and closing timings of said exhaust means such that said piston reciprocates within said cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase,
said control unit being operative during selection of said gasoline reform auto-ignition combustion mode to provide a first start time of a first fuel injection by said fuel injector during said exhaust gas retaining phase and a second start time of a second fuel injection by said fuel injector during said compression phase,
said control unit determining total fuel quantity to be injected in response to engine load of the internal combustion engine,
said control unit being operative during selection of said gasoline reform auto-ignition combustion mode to determine a portion of and the remainder of said determined total fuel quantity,
said control unit being operative during selection of said gasoline reform auto-ignition combustion mode to determine a first fuel injection control signal indicative of said portion of said determined total fuel quantity and applying said first fuel injection control signal to said fuel injector at said first start time to control fuel quantity injected for said first fuel injection,
said control unit being operative during selection of said gasoline reform auto-ignition combustion mode to determine a second fuel injection control signal indicative of the remainder of said determined total fuel quantity and applying said second fuel injection control signal at said second start time to control fuel quantity injected for said second fuel injection.
10. The system as claimed in claim 9, wherein said operating parameter is indicative of the engine load and wherein said control unit calculates said operating parameter indicative of the engine load in response to an accelerator pedal position and the engine speed.
11. The system as claimed in claim 9, wherein said operating parameter is indicative of the engine load of the internal combustion engine, and wherein said control unit selects said gasoline reform auto-ignition combustion mode when the engine load is less than a predetermined value.
12. The system as claimed in claim 11,
wherein said control unit selects said auto-ignition combustion mode when the engine load exceeds said predetermined value,
wherein said control unit is operative during selection of said auto-ignition stratified charge combustion mode to adjust opening and closing timings of said intake means and opening and closing timings of said exhaust means such that said piston reciprocates within said cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase,
wherein said control unit is operative during selection of said auto-ignition combustion mode to provide a third start time of a third fuel injection by said fuel injector during said intake phase and said compression phase, and
wherein said control unit is operative during selection of said auto-ignition combustion mode to determine a third fuel injection control signal indicative of said determined total fuel quantity and applying said third fuel injection control signal at said third start time to control fuel quantity injected for said third fuel injection.
13. The system as claimed in claim 9, wherein said control unit is operative during selection of said gasoline reform auto-ignition combustion mode to hold said first start time and said second start time invariable against variation in the engine load.
14. The system as claimed in claim 9, wherein said control unit is operative during selection of said gasoline reform auto-ignition combustion mode to hold said first start time invariable against variation in the engine load and adjust said second start time in response to the engine load such that said second start time advances as the engine load increases.
15. The system as claimed in claim 9, wherein said operating parameter is indicative of the engine speed of the internal combustion engine, and wherein said control unit selects said auto-ignition combustion mode when the engine speed is greater than a predetermined value.
16. The system as claimed in claim 15,
wherein said control unit selects said auto-ignition combustion mode when the engine speed drops below said predetermined value,
wherein said control unit is operative during selection of said auto-ignition combustion mode to adjust opening and closing timings of said intake means and opening and closing timings of said exhaust means such that said piston reciprocates within said cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase,
wherein said control unit is operative during selection of said auto-ignition combustion mode to provide a third start time of a third fuel injection by said fuel injector during said intake phase and said compression phase, and
wherein said control unit is operative during selection of said auto-ignition combustion mode to determine a third fuel injection control signal indicative of said determined total fuel quantity and applying said third fuel injection control signal at said third start time to control fuel quantity injected for said third fuel injection.
17. The system as claimed in claim 15, wherein said control unit is operative during selection of said gasoline reform auto-ignition combustion mode to adjust said first start time in response to the engine speed such that said first start time advances as the engine speed increases and to hold said second start time invariable against variation in the engine speed.
18. The system as claimed in claim 15, wherein said control unit is operative during selection of said gasoline reform auto-ignition combustion mode to hold said first start time invariable against variation in the engine speed and to adjust said second start time in response to the engine speed such that said second start time advances as the engine speed increases.
19. A computer readable storage device having stored therein data representing instructions executable by a computer to implement an auto-ignition of gasoline internal combustion engine, the engine having a piston disposed in a cylinder for reciprocating motion to define a combustion chamber, intake means for admitting fresh air into the cylinder, a fuel injector directly communicating with the combustion chamber, and exhaust means for discharging exhaust gas resulting from combustion within the cylinder, wherein opening and closing timings of the intake means and opening and closing timings of the exhaust means are adjustable, the computer readable storage device comprising:
instructions for adjusting opening and closing timings of the intake means and opening and closing timings of the exhaust means such that the piston reciprocates within the cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase;
instructions for providing a first start time of a first fuel injection by the fuel injector during said exhaust gas retaining phase and a second start time of a second fuel injection by the fuel injector during said compression phase;
instructions for determining a portion of total fuel quantity and the remainder of said total fuel quantity;
instructions for determining a first fuel injection control signal indicative of said portion of said total fuel quantity and applying said first fuel injection control signal to the fuel injector at said first start time to control fuel quantity injected for said first fuel injection; and
instructions for determining a second fuel injection control signal indicative of the remainder of said total fuel quantity and applying said second fuel injection control signal to the fuel injector at said second start time to control fuel quantity injected for said second fuel injection.
20. A computer readable storage device having stored therein data representing instructions executable by a computer to implement an auto-ignition of gasoline internal combustion engine, the engine having a piston disposed in a cylinder for reciprocating motion to define a combustion chamber, intake means for admitting fresh air into the cylinder, a fuel injector directly communicating with the combustion chamber, and exhaust means for discharging exhaust gas resulting from combustion within the cylinder, wherein opening and closing timings of the intake means and opening and closing timings of the exhaust means are adjustable, the computer readable storage device comprising:
instructions for selecting one of a gasoline reform auto-ignition combustion mode and an auto-ignition combustion mode in response to magnitude of an operating parameter indicative of one of the engine load and the engine speed of the internal combustion engine;
instructions for adjusting, during selection of said gasoline reform auto-ignition combustion mode, opening and closing timings of the intake means and opening and closing timings of the exhaust means such that the piston reciprocates within the cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase;
instructions for providing, during selection of said gasoline reform auto-ignition combustion mode, a first start time of a first fuel injection by the fuel injector during said exhaust gas retaining phase and a second start time of a second fuel injection by the fuel injector during said compression phase;
instructions for determining total fuel quantity to be injected in response to engine load of the internal combustion engine;
instructions for determining, during selection of said gasoline reform auto-ignition combustion mode, a portion of and the remainder of said determined total fuel quantity;
instructions for determining, during selection of said gasoline reform auto-ignition combustion mode, a first fuel injection control signal indicative of said portion of said determined total fuel quantity and applying said first fuel injection control signal to the fuel injector at said first start time to control fuel quantity injected for said first fuel injection; and
instructions for determining, during selection of said gasoline reform auto-ignition combustion mode, a second fuel injection control signal indicative of the remainder of said determined total fuel quantity and applying said second fuel injection control signal to the fuel injector at said second start time to control fuel quantity injected for said second fuel injection.
21. A method for an auto-ignition of gasoline internal combustion engine, the engine having a piston disposed in a cylinder for reciprocating motion to define a combustion chamber, intake means for admitting fresh air into the cylinder, a fuel injector directly communicating with the combustion chamber, and exhaust means for discharging exhaust gas resulting from combustion within the cylinder, wherein opening and closing timings of the intake means and opening and closing timings of the exhaust means are adjustable, the method comprising:
adjusting opening and closing timings of the intake means and opening and closing timings of the exhaust means such that the piston reciprocates within the cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase;
providing a first start time of a first fuel injection by the fuel injector during said exhaust gas retaining phase and a second start time of a second fuel injection by the fuel injector during said compression phase;
determining a portion of total fuel quantity and the remainder of said total fuel quantity;
determining a first fuel injection control signal indicative of said portion of said total fuel quantity;
determining a second fuel injection control signal indicative of the remainder of said total fuel quantity;
applying said first fuel injection control signal to the fuel injector at said first start time to control fuel quantity injected for said first fuel injection; and
applying said second fuel injection control signal at said second start time to control fuel quantity injected for said second fuel injection.
22. A method for an auto-ignition of gasoline internal combustion engine, the engine having a piston disposed in a cylinder for reciprocating motion to define a combustion chamber, intake means for admitting fresh air into the cylinder, a fuel injector directly communicating with the combustion chamber, and exhaust means for discharging exhaust gas resulting from combustion within the cylinder, wherein opening and closing timings of the intake means and opening and closing timings of the exhaust means are adjustable, the method comprising:
selecting one of a gasoline reform auto-ignition combustion mode and an auto-ignition combustion mode in response to magnitude of an operating parameter indicative of one of the engine load and the engine speed of the internal combustion engine;
adjusting, during selection of said gasoline reform auto-ignition combustion mode, opening and closing timings of the intake means and opening and closing timings of the exhaust means such that the piston reciprocates within the cylinder to perform an exhaust phase, an exhaust gas retaining phase, an intake phase, a compression phase, and an expansion phase;
providing, during selection of said gasoline reform auto-ignition combustion mode, a first start time of a first fuel injection by the fuel injector during said exhaust gas retaining phase and a second start time of a second fuel injection by the fuel injector during said compression phase;
determining total fuel quantity to be injected in response to the engine load of the internal combustion engine;
determining, during selection of said gasoline reform auto-ignition combustion mode, a portion of and the remainder of said determined total fuel quantity;
determining, during selection of said gasoline reform auto-ignition combustion mode, a first fuel injection control signal indicative of said portion of said determined total fuel quantity;
determining, during selection of said gasoline reform auto-ignition combustion mode, a second fuel injection control signal indicative of the remainder of said determined total fuel quantity;
applying said first fuel injection control signal to the fuel injector at said first start time to control fuel quantity injected for said first fuel injection; and
applying said second fuel injection control signal to the fuel injector at said second start time to control fuel quantity injected for said second fuel injection.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A digital amplitude modulator for modulating the amplitude of an input carrier signal based on input digital data and generating a corresponding output signal, the digital amplitude modulator including:
a first variable gain amplifier for receiving the input carrier signal and generating a corresponding first amplified carrier signal;
a second variable gain amplifier for receiving the input digital data and generating corresponding digital amplitude control data;
a plurality of selectively activatable amplifier stages, each one receiving a replica of the first amplified carrier signal and generating a corresponding second amplified carrier signal when activated, the output signal corresponding to a combination of the second amplified carrier signals generated by the activated amplifier stages;
a driving circuit configured to receive the digital amplitude control data and activate a corresponding set of selected amplifier stages based on the digital amplitude control data, and
a power controller unit configured to adjust the power delivered by the digital amplitude modulator by setting a first amplifying gain of the first variable gain amplifier and a second amplifying gain of the second variable gain amplifier.
2. The digital amplitude modulator of claim 1, wherein:
in response to a request for decreasing the power delivered by the digital amplitude modulator, the power controller unit is configured to decrease the second amplifying gain if the resolution of the digital amplitude control data is higher than a minimum threshold, or decrease the first amplifying gain if the resolution of the digital amplitude control data is lower than or equal to the minimum threshold, and
in response to a request for increasing the power delivered by the digital amplitude modulator, the power controller unit is configured to increase the second amplifying gain if the amplitude of the first amplified carrier signal is higher than or equal to a maximum threshold, or increase the first amplifying gain if the amplitude of the first amplified carrier signal is lower than the maximum threshold.
3. The digital amplitude modulator of claim 1, wherein the plurality of selectively activatable amplifier stages includes:
a first set of amplifier stages, all the amplifier stages of the first set having a same base amplifying gain, and
a second set of amplifier stages, each amplifier stage of the second set having a respective fractional amplifying gain corresponding to a respective fraction of the base amplifier gain.
4. The digital amplitude modulator claim 1, wherein each amplifier stage includes:
a single gain stage having an input terminal configured to receive the replica of the first amplified carrier signal and an output terminal configured to provide the second amplified carrier signal, or
a sequence of gain stages each one having an input terminal and an output terminal, the input terminal of each gain stage in the sequence different from a first gain stage of the sequence being connected to the output terminal of the preceding gain stage in the sequence, the input terminal of the first gain stage being configured to receive the replica of the first amplified carrier signal, the output terminal of a last gain stage of the sequence being configured to provide the second amplified carrier signal.
5. The digital amplitude modulator of claim 4, wherein at least one gain stage of the amplifier stage includes:
a first transistor having a control terminal coupled with the input terminal through a first capacitor, a first conduction terminal coupled with a terminal providing a reference voltage and a second conduction terminal coupled with the output terminal, and
a first resistor having a first terminal coupled with a terminal providing a bias voltage through a first controlled switch and a second terminal coupled with the control terminal of the first transistor, wherein:
the control terminal of the first transistor is further coupled with a terminal providing the reference voltage through a second controlled switch, and
the first and the second controlled switches are controlled by the driving circuit based on the digital amplitude control data.
6. The digital amplitude modulator of claim 4, wherein at least one gain stage of the amplifier stage includes:
a second transistor of a first conductivity type having a control terminal coupled with the input terminal through a second capacitor and a second controlled switch, a first conduction terminal coupled with a terminal providing a reference voltage and a second conduction terminal coupled with the output terminal,
a third transistor of a second conductivity type opposite to the first conductivity type, the third transistor having a control terminal coupled with the input terminal through a third controlled switch, a first conduction terminal coupled with the second conduction terminal of the second transistor and a second conduction terminal coupled with a terminal providing a bias voltage, and
a second resistor having a first terminal coupled with the control terminal of the second transistor and a second terminal coupled with the output terminal, wherein
the control terminal of the third transistor is further coupled with a terminal providing the reference voltage through a fourth controlled switch and to the second conduction terminal of the third transistor through a fifth controlled switch, and
the second, third, fourth and fifth controlled switches are controlled by the driving circuit based on the digital amplitude control data.
7. The digital amplitude modulator of claim 4, wherein at least one gain stage of the amplifier stage includes:
a fourth transistor of a first conductivity type having a control terminal coupled with the input terminal through a third capacitor, a first conduction terminal coupled with a terminal providing a reference voltage and a second conduction terminal coupled with the output terminal,
a fifth transistor of a second conductivity type opposite to the first conductivity type, the fifth transistor having a control terminal coupled with the input terminal, a first conduction terminal coupled with the second conduction terminal of the fourth transistor and a second conduction terminal coupled with a terminal providing a bias voltage through a sixth controlled switch, and
a third resistor having a first terminal coupled with the control terminal of the fourth transistor and a second terminal coupled with the output terminal, wherein
the second terminal of the fourth transistor is further coupled with a terminal providing the reference voltage through a seventh controlled switch, and
the sixth and seventh controlled switches are controlled by the driving circuit based on the digital amplitude control data.
8. The digital amplitude modulator of claim 4, wherein at least one gain stage of the amplifier stage is a differential gain stage having a further input terminal and a further output terminal, said at least one gain stage including:
a sixth transistor of a first conductivity type having a control terminal coupled with the input terminal through a fourth capacitor, a first conduction terminal coupled with a terminal providing a reference voltage and a second conduction terminal coupled with the output terminal,
a seventh transistor of a second conductivity type opposite to the first conductivity type, the fifth transistor having a control terminal coupled with the input terminal, a first conduction terminal coupled with the second conduction terminal of the sixth transistor and a second conduction terminal coupled with a terminal providing a bias voltage through an eighth controlled switch,
a fourth resistor having a first terminal coupled with the control terminal of the sixth transistor and a second terminal coupled with the output terminal,
an eighth transistor of the first conductivity type having a control terminal coupled with the further input terminal through a fifth capacitor, a first conduction terminal coupled with a terminal providing a reference voltage and a second conduction terminal coupled with the further output terminal, and
a ninth transistor of the second conductivity type having a control terminal coupled with the further input terminal, a first conduction terminal coupled with the second conduction terminal of the eighth transistor and a second conduction terminal coupled with the second conduction terminal of the seventh transistor,
a fifth resistor having a first terminal coupled with the control terminal of the eighth transistor and a second terminal coupled with the further output terminal, wherein
the output terminal is coupled with the output terminal through a ninth controlled switch, and
the eighth and ninth controlled switches are controlled by the driving circuit based on the digital amplitude control data.
9. A method for operating a digital amplitude modulator configured to modulate the amplitude of an input carrier signal based on input digital data and generate a corresponding output signal and including a plurality of selectively activatable amplifier stages, the method comprising the following steps:
generating a first amplified carrier signal by multiplying the input carrier signal by a first amplifying gain,
generating digital amplitude control data by multiplying the input digital data by a second amplifying gain,
providing a replica of the first amplified carrier signal to each amplifier stage, each amplifier stage being configured to generate a corresponding second amplified carrier signal when activated,
activating a set of selected amplifier stages based on the digital amplitude control data, the output signal corresponding to a combination of the second amplified carrier signals generated by the activated amplifier stages,
adjusting the power delivered by the digital amplitude modulator by setting the first amplifying gain and the second amplifying gain.
10. The method of claim 9, wherein:
in response to a request for decreasing the power delivered by the digital amplitude modulator, the step of adjusting the power includes decreasing the second amplifying gain if the resolution of the digital amplitude control data is higher than a minimum threshold, or decreasing the first amplifying gain if the resolution of the digital amplitude control data is lower than or equal to the minimum threshold, and
in response to a request for increasing the power delivered by the digital amplitude modulator, the step of adjusting the power includes increasing the second amplifying gain if the amplitude of the first amplified carrier signal is higher than or equal to a maximum threshold, or increasing the first amplifying gain if the amplitude of the first amplified carrier signal is lower than the maximum threshold.
11. A digital amplitude modulator, comprising:
a variable gain amplifier adapted to receive a carrier signal and a digital amplitude control signal, the variable gain amplifier operable to apply a first gain to the carrier signal to generate a first amplified carrier signal and to apply a second gain to the digital amplitude control signal to generate an amplified digital amplitude control signal and to decode the amplified digital amplitude control signal to generate digital control signals, the second gain having a value that is independent of the value of the first gain;
a plurality of amplifier stages coupled to the variable gain amplifier, each amplifier stage receiving a replica of the first amplified carrier signal and a corresponding one of the digital control signals and operable when activated by the corresponding digital control signal to generate a corresponding second amplified carrier signal;
a combining circuit coupled to the plurality of amplifier stages, the combining circuit operable to generate an output signal having a value that is proportional to the sum of second amplified carrier signals provided by the activated amplifier stages; and
a power control circuit coupled to the variable gain amplifier and adapted to receive a power control command signal,
the power control circuit operable in a first mode responsive to the power control command signal indicating the power of the output signal should be decreased to reduce the second gain if a resolution of the amplified digital amplitude control signal is greater than a first threshold value and to reduce the first gain if the resolution of the amplified digital amplitude control signal is less than or equal to the first threshold value, and
the power control circuit operable in a second mode responsive to the power control command signal indicating the power of the output signal should be increased to raise the second gain if the first amplified carrier signal has an amplitude that has reached a second threshold value and to raise the first gain if the first amplified carrier signal has an amplitude that is less than the second threshold value.
12. The digital amplitude modulator of claim 11 wherein the variable gain amplifier is further operable to phase shift the first amplified input carrier signal relative to the input carrier signal.
13. The digital amplitude modulator of claim 11 wherein there are N+M amplifier stages, N amplifier stages having a unit gain A0 and M amplifier stages having fractional unit gains having a value less than the unit gain A0.
14. The digital amplitude modulator of claim 13 wherein the M amplifier stages have respective fractional unit gains given by A02X where X varies from 1 to M for these M amplifier stages.
15. The digital amplitude modulator of claim 11 wherein the variable gain amplifier comprises:
a first variable gain amplifier adapted to receive the carrier signal and apply the first gain to the carrier signal to generate the first amplified carrier signal;
a signal splitting circuit coupled to the first variable gain amplifier and operable responsive to the first amplified carrier signal to generate the replica of the first amplified carrier signal applied to each amplifier stage;
a second variable gain amplifier adapted to receive the digital amplitude control signal and operable to apply the second gain to the digital amplitude control signal to generate the amplified digital amplitude control signal; and
a digital decoder circuit coupled to the second variable gain amplifier to receive the amplified input signal data and to decode the amplified input signal data to generate the digital control signals.
16. The digital amplitude modulator of claim 11 wherein each amplifier stage comprises a single gain stage having an input node adapted to receive the replica of the first amplified carrier signal and an output node coupled to the combining circuit.
17. The digital amplitude modulator of claim 11 wherein each amplifier stage comprises a plurality of gain stages connected in series between an input node adapted to receive the replica of the first amplified carrier signal and an output node coupled to the combining circuit.
18. The digital amplitude modulator of claim 17 wherein each amplifier stage comprises:
a differential gain stage including,
a first capacitive element;
a first transistor having a control node coupled to a first input node through the first capacitive element, a first conduction node adapted to receive a reference voltage and a second conduction node coupled to a first output node;
a second transistor having a control node coupled to the first input node, a first conduction node coupled to the first output node and a second conduction node coupled to a biasing node;
a biasing transistor having a control node coupled to receive an enable signal, a first conduction node adapted to receive a supply voltage and a second conduction node coupled to the biasing node;
a first resistive element having a first node coupled to the control node of the first transistor and a second node coupled to the first output node;
a second capacitive element;
a third transistor having a control node coupled to a second input node through the second capacitive element, a first conduction node adapted to receive the reference voltage and a second conduction node coupled to a second output node;
a fourth transistor having a control node coupled to the second input node, a first conduction node coupled to the second output node and a second conduction node coupled to the biasing node;
a second resistive element having a first node coupled to the control node of the third transistor and a second node coupled to the second output node;
a fifth transistor having first and second conduction nodes coupled to the first and second output nodes, respectively, and having a control node coupled to receive the enable signal;
a control circuit adapted to receive a clocking signal and operable responsive to the clocking signal to generate the enable signal;

a second stage including,
a sixth transistor having a control node coupled to the first output node, a first conduction node adapted to receive the reference voltage and a second conduction node coupled to a first final output node;
a seventh transistor having a control node coupled to the second output node, a first conduction node adapted to receive the reference voltage and a second conduction node coupled to a second final output node
an eighth transistor having a control node coupled to the control circuit to receive the enable signal, a first conduction node adapted to receive the reference voltage and a second conduction node coupled to the control node of the sixth transistor; and
a ninth transistor having a control node coupled to the control circuit to receive the enable signal, a first conduction node adapted to receive the reference voltage and a second conduction node coupled to the control node of the seventh transistor.
19. An electronic system, comprising:
first and second digital amplitude modulators adapted to receive first and second carrier signals, respectively, the first and second carrier signals being in quadrature and each of the digital amplitude modulators comprising,
a variable gain amplifier adapted to receive the corresponding carrier signal and a digital amplitude control signal, the variable gain amplifier operable to apply a first gain to the carrier signal to generate a first amplified carrier signal and to apply a second gain to the digital amplitude control signal to generate an amplified digital amplitude control signal and to decode the amplified digital amplitude control signal to generate digital control signals, the second gain having a value that is independent of the value of the first gain;
a plurality of amplifier stages coupled to the variable gain amplifier, each amplifier stage receiving a replica of the first amplified carrier signal and a corresponding one of the digital control signals and operable when activated by the corresponding digital control signal to generate a corresponding second amplified carrier signal;
a combining circuit coupled to the plurality of amplifier stages, the combining circuit operable to generate an output signal having a value that is proportional to the sum of second amplified carrier signals provided by the activated amplifier stages;
a power control circuit coupled to the variable gain amplifier and adapted to receive a power control command signal,
the power control circuit operable in a first mode responsive to the power control command signal indicating the power of the output signal should be decreased to reduce the second gain if a resolution of the amplified digital amplitude control signal is greater than a first threshold value and to reduce the first gain if the resolution of the amplified digital amplitude control signal is less than or equal to the first threshold value, and
the power control circuit operable in a second mode responsive to the power control command signal indicating the power of the output signal should be increased to raise the second gain if the first amplified carrier signal has an amplitude that has reached a second threshold value and to raise the first gain if the first amplified carrier signal has an amplitude that is less than the second threshold value; and

a summing circuit operable to sum the output signals from the first and second digital amplitude modulators to generate an overall output signal.
20. The electronic system of claim 19 wherein the electronic system comprises a wireless mobile electronic device.
21. A method for operating a digital amplitude modulator, comprising:
signal;
multiplying a carrier signal by a first gain to generate an amplified carrier
multiplying a digital amplitude control signal by a second gain to generate an amplified digital amplitude control signal;
splitting the amplified carrier signal to generate X corresponding split amplified carrier signals where X is an integer;
multiplying Y split amplified carrier signals by a corresponding stage gain where Y is an integer that is less than or equal to X and Y has a value determined from the amplified digital amplitude control signal;
combining the Y split amplified carrier signal to generate an output signal;
controlling the power of the output signal in a first mode when a power control command signal indicates the power of the output signal is to be decreased by,
lowering the second gain when a resolution of the amplified digital amplitude control signal is greater than a first threshold value,
lowering the first gain when the resolution of the digital amplitude control signal is less than or equal to the first threshold value; and

controlling the power of the output signal in a second mode when the power control command signal indicates the power of the output signal is to be increased by,
raising the second gain when the first amplified carrier signal has an amplitude that has reached a second threshold value, and
raising the first gain when the amplified carrier signal has an amplitude that is less than the second threshold value.
22. The method of claim 21 wherein multiplying the carrier signal by the first gain further comprising shifting a phase of the carrier signal.
23. The method of claim 21 wherein multiplying Y split amplified carrier signals comprises:
multiplying N split amplified carrier signals by a first stage gain where N is an integer that is less than Y and N is determined by the value of the amplified digital amplitude control signal; and
multiplying at least some of Y-N amplified carrier signals by respective fractional stage gains, wherein each respective fractional stage gain has value that is a different fraction of the first gain and number of the Y-N amplified carrier signals that are multiplied by fractional stage gains and the specific fractional stage gains utilized are determined by the amplified digital amplitude control signal.
24. The method of claim 21 wherein the carrier signal comprises an RF signal.
25. The method of claim 21 wherein the RF signal has a frequency in the range of 0.7 to 5.8 GHz.