Distortion-compensated RF transmitter and method therefor

摘要

An RF transmitter (10) includes an RF amplifier (28) that generates an amplified RF signal (36) including a linear RF signal (92) and a spurious baseband signal (94). The spurious baseband signal (94) interacts with bias feed networks (56, 66) to cause the RF amplifier (28) to generate an unwanted RF distortion at or near the allocated RF bandwidth. A baseband compensation signal (98) is generated and equalized in an adaptive equalizer (102) then fed to the RF amplifier (28). A feedback signal (46) is obtained from the RF amplifier (28) and used to drive the adaptive equalizer (102). A feedback loop causes the adaptive equalizer to adjust a baseband signal (24, 32) supplied to the RF amplifier (28) so that the RF distortion is minimized.

主权项

1. A distortion-compensated radio-frequency (RF) transmitter comprising:
an RF amplifier that generates an amplified RF signal which includes a spurious baseband signal, said amplified RF signal being generated in response to an RF communication signal supplied to an input of said RF amplifier; a signal processor having an output coupled to said input of said RF amplifier, said signal processor being configured to digitally generate a baseband compensation signal corresponding to said RF communication signal, to apply equalization to said baseband compensation signal to produce an equalized baseband compensation signal, and to convert said equalized baseband compensation signal into an analog equalized baseband compensation signal which is applied at baseband to said input of said RF amplifier; and a feedback processor having an input coupled to said RF amplifier and having an output coupled to said signal processor; wherein said signal processor is further configured so that said equalization applied to said baseband compensation signal adapts to minimize RF distortion in said amplified RF signal caused by said spurious baseband signal.