Experimental setup for the extraction of power amplifier dynamic volterra model and design of digital baseband predistorter

This paper deals with the two-memory path nonlinear integral model introduced previously which has shown that it accurately reproduces the nonlinear memory effects in Radio Frequency Amplifiers. Due to the relative complexity of the required measurement setup, the model presented has thus far been extracted and validated upon circuit simulations only. Here, we present a relatively simple and effective experimental setup procedure to identify the PA model. Furthermore, using the same setup we have been able to extract both the PA model and its inverse characteristic, leading directly to the design of a digital linearizer able to compensate effectively for the nonlinear memory effects. The linearizer has shown the capability to reduce significantly the spectral regrowth for different kinds of signals that differ fundamentally from the extraction stimulus. Experimental results carried out on a 10 dB gain GaAs power amplifier are presented for both the power amplifier and predistorter identification.