Accurate Characterization of TWTA Distortion in Multicarrier Operation by Means of a Correlation-Based Method

Complex payload architectures, together with the use of high-order digital modulations and advanced coding schemes, call for an accurate evaluation of traveling-wave tube amplifier (TWTA) nonlinearity impairments. To assess in a simple yet accurate manner the level of signal distortion generated by the TWTA nonlinearity, we adopt a correlation-based methodology. The proposed method provides an accurate evaluation of the TWTA intermodulation, particularly in the presence of multicarrier operation with nonconstant envelope modulations.