A High-Linearity Wideband Power Amplifier With Cascaded Third-Order Analog Predistorters

A high-linearity wideband analog predistortion power amplifier (PA) is presented. The memory effects of the PA are reduced by a high drain bias voltage as well as a wide bias line and several decoupling capacitors. The simple cascaded third-order analog predistorters (CTAPDs) are used to cancel the third- and fifth-order intermodulations (IM3s and IM5s) of the low-memory PA. For verification, the 45 W class-AB PA is implemented and tested using a two-tone signal and a four-carrier wideband code division multiple access (WCDMA) signals at 2.14 GHz. From the measured results, the low-memory PA with the CTAPDs delivers significant IM3 and IM5 cancellation and superior ACLR improvement.