Wideband LDMOS-based RF linearizer for multi-carrier 3G high power amplifier

We propose a LDMOS based RF predistortion linearizer suitable for the 3G systems. By using same type of transistors in linearizer as in high power amplifier we can obtain quasi-inverse curves of AM/AM and AM/PM. It has the advantage of compensating temperature variations. Furthermore it has a wideband performance by equalizing the group delay of the linear path and nonlinear path having the same components, respectively. By applying this linearizer to the base station 310 W power amplifier we obtain 6.5 dB improvement at 3rd offset of ACPR and obtain 2 dB power increase at same linearity at 44 dBm average output power with 8% power efficiency for cdma2000 (SR3) multi-carrier signal.