A Broadband Almost Digital RF Transmitter With an Efficient Power Amplifier
A new architecture of an almost digital RF transmitter is proposed. It consists of easy to have functional modules. Among the modules, a broadband Doherty amplifier is focused through a modified design approach. A proof of concept transmitter is built and measured. It demonstrates quite comparable performances: more than 40% of power amplifier efficiency, adjacent channel leakage ratios between 26 and 37 dB, and average 2.6% of error vector magnitude over a frequency band from 0.7 to 1.1 GHz, which corresponds to a fractional bandwidth of 44% when it is driven by a signal with 5.6 dB of peak to average power ratio.
IEEE Transactions on Microwave Theory and Techniques