Multitone ACLR and Its Applications to Linear PA Design

Analysis and measurements results of a multitone frequency spectrum leakage have shown results comparable to those of modulated signals with a similar peak-to-average power ratio. In this brief, the adjacent channel leakage ratio of multitone signals is analyzed, and it is shown that the closed-form result is related to third-order intermodulation distortion that can be obtained by a two-tone test. Such a correlation enables a rough prediction of an RF power amplifier's (PA) linearity performance through a simple and fast simulation of a two-tone test, thereby shortening the design time. The theoretical analysis is experimentally demonstrated by employing a 1.9-GHz PA fabricated in 40-nm CMOS technology.