US 10,381,985 B2 · Power amplifier linearization system and method

Abstract

Envelope tracking can be employed to reduce power consumption of a power amplifier, but envelope tracking can introduce nonlinearities to a power amplifier. These nonlinearities can manifest themselves as noise at the output of the power amplifier. Embodiments described herein provide techniques for characterizing a parameter indicative of power amplifier noise when envelope tracking is employed. Measurement of this parameter can permit power amplifier designers to decide whether to forgo envelope tracking if a power amplifier is too susceptible to such noise, redesign the power amplifier to improve compatibility with envelope tracking, or to employ distortion compensation circuitry to reduce the noise output by the power amplifier. Counterintuitively, this distortion compensation circuitry may involve increasing the power, such as the envelope tracking power supply. However, increasing the power may be a desirable trade-off for increased linearity.

Claims20

Dependent claims

An envelope tracker characterization method comprising:

providing a first input signal to a power amplifier;
providing a second input signal to an envelope tracker circuit that generates a supply voltage signal for the power amplifier by tracking an envelope of the second input signal;
measuring intermodulation distortion at the output of the power amplifier;
calculating an intermodulation distortion phase angle based on the measured intermodulation distortion and the amount of delay, the intermodulation distortion phase angle indicative of linearity of the power amplifier;
and
comparing the intermodulation distortion phase angle with a threshold to analyze suitability of the power amplifier for use with the envelope tracker.

3 more elements

Dependencies are inferred from the claim text.

Power amplifier linearization system and method

Life of this patent

Power amplifier linearization system and method

Life of this patent

Abstract

Claims20