Digitally assisted adaptive non-linearity suppression scheme for RF front ends

This paper presents a robust and low-complexity non-linearity suppression scheme for radio frequency (RF) transceiver building blocks to efficiently mitigate intermodulation distortion. The scheme consists of tunable RF components assisted by an auxiliary path equipped with an adaptive digital signal processing algorithm to provide the tuning control. This proposed concept of digitally-assisted tuning is capable of handling a large range of non-linear behaviours without any complexity increase in the expensive RF circuitry and is robust to process, voltage and temperature variations. A case study on the third order intermodulation of the channel select filter for a full 10MHz Long Term Evolution (LTE) reception bandwidth is used to demonstrate the feasibility and effectiveness of the technique.