A Novel Two-Dimensional Crest Factor Reduction for Performance Improvement of RF Power Amplifiers

In this letter, a novel two-dimensional crest factor reduction (2D-CFR) technique is proposed. It works together with dual-band digital predistortion (DPD) to enhance the performance of concurrent dual-band or broadband power amplifiers (PAs). During peak detection process, this new method introduces the instantaneous difference between the two bands to determine the amount of reduction. Theoretical analysis is performed to compare the proposed approach and the conventional approaches. To evaluate the performance of the proposed method, a broadband PA is excited by a dual-band signal composed of a 5 MHz wideband code division multiple access (WCDMA) signal and a 5 MHz long-term evolution (LTE) signal with edge to edge separation of 85 MHz. The experimental results demonstrate that the average error vector magnitude (EVM) is reduced from 3.35% to 1.85% without sacrificing the performance of linearity and efficiency.