A wideband multi-branch analog predistorter with memory-effect compensation for multi-carrier WCDMA repeater systems

A wideband multi-branch analog predistorter (MBAPD) is reported to compensate for memory effects as well as memoryless nonlinearity of the power amplifier (PA) for multi-carrier wideband code division multiple access (WCDMA) repeater systems. For verification, the MBAPD with three-branch nonlinear path is implemented with a 30-W class-AB PA and tested using 4- and 8-carrier WCDMA signals (signal bandwidth of 20 MHz and 40 MHz, respectively) at 2.14 GHz. From the measured results at an average output power of 33 dBm, the proposed MBAPD shows the adjacent channel leakage ratios (ACLRs) at plusmn5 MHz offset of -54.3 dBc and -51.2 dBc for 4-and 8-carrier WCDMA signals, which are the improvement of over 20 dB and 10 dB, compared to the PAs without APD and with conventional APD, respectively.