Pre-Distortion for Power Amplifiers. Interested?

Driven by a high data rate and need for efficient spectrum utilization, modern communication standards like MoCA usually feature OFDM which has a high peak to average power ratio (PAPR). This constrains the designers to resort to the most linear version of PA, a Class-A PA. In addition to having a poor maximum efficiency, a Class-A PA’s efficiency degrades rapidly under back-off. On the other hand, a Class-B PA, albeit very non-linear compared to a Class-A PA, has a higher maximum efficiency and it degrades less rapidly under back-off.

Similar to the idea of pre-equalization used in communication, the input signal of the PA could be pre-distorted effectively to compensate for its non-linearity. In standard CMOS process, particularly with technology downscaling, the cost of digital signal processing has reduced dramatically, making it a smart choice to implement the pre-distortion in the digital domain.

If you are interested in working on this problem, please contact me.

Karthik

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