2015 Volume 12 Issue 16 Pages 20150446
Pre-distortion approach is used in frequency synthesizers to compensate the statistical phase errors in the synthesized signal. However, as the systems becoming more and more complex, it is hard to describe the phase errors for a complex system with one single model. In this paper, a hybrid pre-distortion approach was proposed for a transmitter composed of different modules with high frequency modulation rate. Models for different modules are combined to form the hybrid distortion model. Based on the proposed model and the convenience of the Direct Digital Waveform Synthesis (DDWS) technology employed in the transmitter, the distortion of a complex system can be feasibly compensated. Experimental studies were performed with reduced phase errors and improved range profiles achieved, which verify the effectiveness of the proposed approach.