US 8,912,937 B2 · High efficiency output stage amplification for radio frequency (RF) transmitters

Abstract

Highly power efficient transmitter output stage designs are provided. In an embodiment, the probability density function (PDF) of an input signal is divided into a plurality of regions, and samples of the input signal are processed depending on the region of the PDF within which they fall. The PDF can be divided between an inner region corresponding to samples of the input signal that are within a predetermined amplitude range, and outer regions corresponding to samples of the input signal that are outside of the predetermined amplitude range. Samples of the input signal that fall in the inner region are processed by a class A biased amplifier and samples of the input signal that fall in the outer regions are processed by a class B biased amplifier. Output stage designs according to embodiments can be implemented as power amplifiers or power digital-to-analog converters (DACs).

Claims20

Dependent claims

A power digital-to-analog converter (DAC), comprising:

an amplitude mapper configured to receive an input signal and to generate a first input constituent signal and a second input constituent signal from the input signal;
a first DAC configured to receive the first input constituent signal and to generate a first current signal;
a second DAC configured to receive the second input constituent signal and to generate a second current signal;
and
a combiner configured to combine the first and second current signals to generate an output signal of the power DAC,
wherein the first DAC is biased with a first supply voltage, and
wherein the second DAC is biased with a second supply voltage higher than the first supply voltage when the second input constituent signal is non-zero, and is biased with a third supply voltage lower than the first supply voltage when the second input constituent signal is zero.

4 more elements

Dependencies are inferred from the claim text.

High efficiency output stage amplification for radio frequency (RF) transmitters

Life of this patent

High efficiency output stage amplification for radio frequency (RF) transmitters

Life of this patent

Abstract

Claims20