A 1000W Wideband Recursive Four-way Doherty Amplifier for Base-station Application

An optimized wideband load impedance selection approach and recursive four-way Doherty power amplifier (DPA) combining topology are introduced in this paper. Theoretical analysis indicates low Q-factor matching network can be achieved adopting this approach, and it will be easier to obtain high efficiency adopting recursive structure. For verification, a 1000W wideband recursive four-way DPA using LDMOS devices operating from 760MHz to 960MHz is implemented. The prototype exhibits the peak power between 59.5dBm and 60.5dBm and an average drain efficiency between 48% and 54% with 9.9 PAR WCDMA signal. It can be linearized under -51dBc level with 2C-LTE signal at an average output power of 50dBm with 200MHz carrier spacing.