Systems and methods for a radio frequency transmitter with improved linearity and power out utilizing pre-distortion and a GaN (gallium nitride) power amplifier device

摘要

Various embodiments provide for systems and methods for increased linear output power of a transmitter. An exemplary wireless communications system for transmitting an input signal comprises a predistorter module, a GaN power amplifier, a coupler, and an antenna. The predistorter module is configured to detect existing distortion by comparing the input signal to a feedback signal and generate a correction signal. The predistorter may adaptively adjust its operation to minimize the existing distortion due to GaN power amplifier nonlinear characteristics. The result is that the GaN power amplifier may send a power signal of improved linearity to the antenna. The coupler is configured to sample the amplified signal from the GaN power amplifier to generate the feedback signal. The antenna is configured to transmit the amplified signal.

主权项

1. A wireless communications system comprising:
a coupler configured to sample a first transmission signal at a transmission radio frequency to generate a feedback signal; a first feedback downconverter configured to downconvert a first signal to an intermediate frequency to generate an intermediate frequency second signal, the first signal being based on the feedback signal from the transmission radio frequency; a predistorter module configured to:
receive an intermediate frequency third signal, the intermediate frequency third signal being based on the intermediate frequency second signal;compare the intermediate frequency third signal to an intermediate frequency input signal to detect existing distortion in the intermediate frequency third signal; andadd inverse distortion to an output signal to generate a distorted output signal with added distortion, the inverse distortion added to the output signal being based on the existing distortion detected in the intermediate frequency third signal; a second upconverter configured to upconvert an intermediate frequency fourth signal to generate a transmission radio frequency fifth signal, the intermediate frequency fourth signal being based on the distorted output signal to the transmission radio frequency; a gallium nitride (GaN) power amplifier configured to amplify power of a transmission radio frequency sixth signal to generate a transmission radio frequency amplified signal, the GaN power amplifier adding amplifier distortion, wherein at least some of the added distortion from the predistorter module cancels at least some of the amplifier distortion, the transmission radio frequency sixth signal being based on the transmission radio frequency fifth signal; and an antenna configured to transmit a transmission radio frequency seventh signal, the seventh signal being based on the transmission radio frequency amplified signal.