Linearization of RF Frontends

Widespread adoption of higher order modulation schemes, larger signal bandwidths and higher operating frequencies, to enable higher data throughput in communication links like 5G, places increasingly tough demands on the frontend. Signal fidelity is often enhanced with linearization.

The greater number of RF chains and signal bandwidth in 5G Frontends mean that DPD (Digital Pre-Distortion) may no longer be the default linearization choice; 5G Frontends will be completely different from their 4G predecessors.

The key metrics of Efficiency, Linearity, Bandwidth and Output Power remain, as does the question of how to optimally create the signal with just enough fidelity and power, with a minimum of wasted power. The solution set to that question, however, has never been greater.

Amongst other topics, this White Paper, (i) proposes a classification of Linearization schemes, (ii) introduces the hard limiter, (iii) illustrates linearization of an exemplary mmWave PA using non-DPD techniques, and (iv) introduces a class of linearized transmitters that create their signal and linearity from efficiently generated components.