RF transmitter with bias-signal-induced distortion compensation and method therefor

摘要

An RF transmitter (60) generates non-DC bias signals (104, 106) configured to improved power-added efficiency (PAE) in the operation of an RF amplifier (94). The RF amplifier (94) generates an amplified RF signal (126) which, due to the addition of the bias signals (104, 106), includes bias-signal-induced RF distortion (48, 50). The bias signals (104, 106) drive a bias-induced distortion cancellation circuit (152) that adjusts the bias signals to compensate for the influence of impedances experienced by the bias signals (104, 106) before being applied to the RF amplifier (94). After mixing with a baseband communication signal (64), adjusted bias signals (186, 188) are combined into a composite baseband signal (76), upconverted to RF in an upconversion section 84, and applied to the RF amplifier (94) where they cancel at least a portion of the bias-signal-induced RF distortion (48, 50).