A new pre-distortion scheme for reduction of inter-modulation distortion in broadband optical SCM systems

A new Pre-Distortion scheme for cancellation of 2nd order Intermodulation (IMD) products in broadband optical SCM systems is presented. This method relies on the phase inversion provided by a common-source FET amplifier, which allows the compensation of the even order distortion products, generated in a cascade of two such stages. Also, it is shown how a careful selection of the FET´s bias point can be a valuable tool for controlling the remaining odd order IMD components.