MODULATOR APPARATUS OPERATING AT LOW SUPPLY VOLTAGE, AND CORRESPONDING METHOD OF MODULATION
First Claim
1. A modulator apparatus operating at a low supply voltage, configured for receiving an input-voltage signal from a base band circuit and supplying an output-voltage signal at a modulation frequency under control of a signal generated by a local oscillator, the modulator apparatus comprising:
- a Gilbert-cell stage which supplies an output-voltage signal under the control of said signal generated by said local oscillator, the Gilbert-cell stage further including an output load for carrying out a current-to-voltage conversion and supplying the output-voltage signal; and
a transconductor stage having;
a voltage-to-current conversion module structured to perform a voltage-to-current conversion of said input-voltage signal and having a differential load;
a differential feedback network configured for reproducing in a proportional way said input-voltage signal on the differential load, and a current-mirror module coupled to said voltage-to-current conversion module and configured for mirroring a current in the Gilbert-cell stage.
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Accused Products
Abstract
A modulator apparatus operating at a low supply voltage, configured for receiving an input-voltage signal in base band and supplying an output-voltage signal at a given modulation frequency under control of a signal generated by a local oscillator and comprising a transconductor stage that carries out a voltage-to-current conversion of said input-voltage signal. A voltage-to-current conversion module is coupled to a current-mirror module configured for mirroring a current in a Gilbert-cell stage, which supplies an output-voltage signal under the control of said signal generated by the local oscillator. The Gilbert-cell stage further comprises an output load for carrying out a current-to-voltage conversion and supplying the output-voltage signal. Said transconductor stage further comprises a differential feedback network configured for reproducing said input-voltage signal on a differential load included in said voltage-to-current conversion module.
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Citations
21 Claims
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1. A modulator apparatus operating at a low supply voltage, configured for receiving an input-voltage signal from a base band circuit and supplying an output-voltage signal at a modulation frequency under control of a signal generated by a local oscillator, the modulator apparatus comprising:
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a Gilbert-cell stage which supplies an output-voltage signal under the control of said signal generated by said local oscillator, the Gilbert-cell stage further including an output load for carrying out a current-to-voltage conversion and supplying the output-voltage signal; and
a transconductor stage having;
a voltage-to-current conversion module structured to perform a voltage-to-current conversion of said input-voltage signal and having a differential load;
a differential feedback network configured for reproducing in a proportional way said input-voltage signal on the differential load, and a current-mirror module coupled to said voltage-to-current conversion module and configured for mirroring a current in the Gilbert-cell stage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of modulation operating at a low supply voltage, comprising:
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receiving an input-voltage signal in base band and supplying an output-voltage signal at a modulation frequency under control of a signal generated by a local oscillator;
carrying out a voltage-to-current conversion of said input-voltage signal and an operation of mirroring of a current obtained;
carrying out a frequency conversion via a Gilbert-cell stage under the control of said signal generated by said local oscillator;
carrying out a current-to-voltage conversion and supplying the output-voltage signal; and
applying a differential feedback for reproducing in a proportional way said input-voltage signal on a differential load that controls said voltage-to-current conversion. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A transconductor circuit comprising:
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a current mirror circuit configured to generate a differential current signal;
a first differential amplifier operable to receive a first voltage signal and generate an output signal to control the current mirror circuit;
a voltage-to-current conversion circuit to receive a second voltage signal proportional to the first voltage signal and convert the second voltage signal to a current signal; and
a second differential amplifier operable to control the voltage-to-current conversion circuit. - View Dependent Claims (20, 21)
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Specification