A Power Amplifier Spectral Asymmetries Modeling Using direct calculation of polynomial parameters and delay taps

This paper presents a power amplifier(PA) cascade model that uses delay taps to obtain the intermodulation distortion(IMD) asymmetries. A new mathematical method is developed, based on the fourier transform of the gain and phase output, to extract the model parameters and delays for each harmonic. The spectral asymmetries are characterized by distortions in the output envelope signal. Thus, to estimate the model coefficients it requires a method capable to also care for nonlinear phenomenons. The deformed envelope spectral analysis is used to achieve a matrix equation system that provides accurate solutions. To demonstrate the performances of this modeling approach, ADS simulations and real measurement data where used.