Nonlinear RF power amplifier behavioural analysis of wireless OFDM systems

Four signal representation approaches are combined with a Bessel-Fourier PA envelope behavioural model of a GaN memoryless nonlinear power amplifier (PA) to reveal insights into the nonlinear amplification of multicarrier OFDM signals. Isolating and analyzing different orders of intermodulation product (IMP) impairment, the impact of higher order IMPs on ACPR degradation in the second and higher adjacent channel bands and how that is the determining factor for the PA´s upper limit operating point and power conversion efficiency, rather than the ACPR in the first adjacent band or the inband EVM degradation, may be shown.