A behaviour model for power amplifiers based on sum of products between one-dimensional polynomials and finite impulse response filters

Power amplifier (PA) behaviour modelling is a crucial technique for the improvement of telecommunication systems because it constitutes the core of a linearisation circuit that allows for the amplifier to develop high efficiencies at the same time that it delivers a linear output signal to the load. Polynomial filters can be used in order to represent both the non-linearities of the PA and the memory effects caused by passive elements of the circuit. This work proposes a different structure for a PA polynomial behaviour model, using finite impulse response (FIR) filters and one-dimensional polynomials. The memory polynomial (MP) and the envelope memory polynomial (EMP) models were used not only as a foundation for the proposed model but also as references points for performance validation. All models were applied to a class AB GaN PA driven by a WCDMA envelope signal. Results shown an enhancement on performance for the proposed model when its accuracy was compared with the one obtained by the MP and EMP models. In contrast with the first one, the proposed model had an improvement of 4.1 dB in its normalized mean square error (NMSE), with the second one, the improvement was of 5.9 dB.