US 8,477,857 B2Granted

Efficient cartesian transmitter using signal combiner

AssigneePanasonic Corporation

InventorsSaleh Osman, Gregoire Le Grand de Mercey

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Abstract

In one embodiment, the present invention includes a transmitter having a baseband, a multiplexer, a digital-to-analog converter unit, and/or a Chireix combiner. The baseband transmits components of an in-phase signal and a quadrature-phase signal to the multiplexer. The multiplexer generates a first signal and/or a second signal which have a phase difference which matches only a single predetermined phase difference. The single predetermined phase difference should be selected to ensure that the Chireix combiner is optimized for efficiency. Thus, a phase of the first signal or the second signal can have a phase of the in-phase signal or the quadrature-phase signal to ensure that the phase difference between the second signal and the first signal matches only the single predetermined phase difference. The Chireix combiner receives the first analog signal and the second analog signal.

Claims19

Dependent claims

A transmitter comprising:

a baseband outputting components of an in-phase signal and components of a quadrature phase signal;
a multiplexer receiving the components of the in-phase signal and the components of the quadrature-phase signal, and outputting a first signal, and a second signal;
a first digital-to-analog converter receiving the first signal and converting the first signal into a first analog signal;
a second digital-to-analog converter receiving the second signal and converting the second signal into a second analog signal;
and
a Chireix combiner, wherein the Chireix combiner includes a capacitor portion and an inductor portion, wherein the capacitor portion receives the first analog signal, and the inductor portion receives the second analog signal,
wherein the multiplexer is configured to select a phase of the first signal to correspond to a phase of the in-phase signal or a phase of the quadrature-phase signal, and select a phase of the second signal to correspond to the phase of the in-phase signal or the phase of the quadrature-phase signal, to ensure that a phase difference between the second signal and the first signal matches only a single predeterminded phase difference of positive 90° or negative 90°, such that the Chireix combiner is optimized for efficiency.

4 more elements

A method for outputting signals in a transmitter comprising:

outputting, using a baseband, components of an in-phase signal and components of a quadrature-phase signal;
receiving, using a multiplexer, the components of the in-phase signal and the components of the quadrature-phase signal;
generating, using the multiplexer, a first signal and a second signal;
selecting, using the multiplexer, a phase of the first signal to correspond to a phase of the in-phase signal or a phase of the quadrature-phase signal;
selecting, using the multiplexer, a phase of the second signal to correspond to the phase of the in-phase signal or the phase of the quadrature-phase signal;
outputting, using the multiplexer, the first signal and the second signal;
and
generating, using a first digital-to-analog converter, a first analog signal from the first signal from the multiplexer;
generating, using a second digital-to-analog signal from the second signal from the multiplexer;
receiving, using a capacitor portion of a Chireix combiner, the first analog signal;
and
receiving, using an inductor portion of the Chireix combiner, the second analog signal,
wherein the phase of the first signal and the phase of the second signal are each selected to ensure that a phase difference between the second signal and the first signal matches only a single predetermined phase difference of positive 90° or negative 90°, such that the Chireix combiner is optimized for efficiency.

10 more elements

Dependencies are inferred from the claim text.