Band-limited Volterra series-based behavioral modeling of RF power amplifiers

In this paper, a new band-limited Volterra series-based behavioral model for RF power amplifiers is proposed. It is achieved by inserting a band-limiting function in the time domain into the Volterra operators to control the bandwidth of the output signal being modeled, which provides a simple and logical way to transform general Volterra series-based models into band-limited versions. An LDMOS Doherty power amplifier excited by a 60 MHz 12-carrier WCDMA signal is tested to validate this approach. Experimental results show that the new approach provides much higher accuracy when mapping the band-limited input to the band-limited output of the power amplifier. This approach can be applied to any Volterra-based behavioral models, and provides a very promising solution for wideband digital predistortion of RF power amplifiers especially in the context of future ultra wideband wireless systems.