A Novel 3rd-and-5th-Order Predistortion Circuit for 2 GHz Band W-CDMA Amplifier

A new analog predistortion (PD) circuit that compensates 3rd-and-5th-order intermodulation distortion (IM3 and IM5) for 2 GHz power amplifiers is proposed. In this method, IM3 is compensated by Cuber Predistortion and IM5 is compensated by 2nd harmonics injection independently. To confirm the proposed technique, a 2 GHz band 45 W class PA and a linearizer are implemented, and linearization experiments to compare the compensation performance of conventional PDs and the proposed PD are performed. Two-tone test results show that the proposed PD suppresses both IM3 and IM5 over a wide output dynamic range when compared with conventional PD. W- CDMA one-carrier tests show that the proposed PD improves the adjacent channel leakage power ratio of the PA by 6 dB when compared with the improvement due to conventional PDs.