50W GaN based multi-band Doherty amplifier proof of concept for LTE with 48 efficiency

摘要

A 50W GaN HEMT based Doherty PA capable of multi-band performance is shown. This implementation demonstrates the performance in Korean PCS, US PCS and IMT-2000 (Band 1) RF bands with similar artwork but different capacitors and RF shorts used in each design. High power DTCs (Digitally tuned capacitors) and switches would allow for extending this design concept to a digitally programmable multi-band Doherty PA. Linearity was optimized with a 5th order, 4-tap memory polynomial DPD system. The PA demonstrated a drain efficiency of 48%, an ACLR of 47 dBc and a power gain of 12.7 dB at average output power of 47 dBm for a 10 MHz LTE signal of 6.5 dB PAR in US PCS band while maintaining similar performance in Korean PCS and IMT-2000 bands.