High-Power High-Efficiency Broadband Doherty Amplifiers

The high-power high-efficiency broadband Doherty power amplifiers based on high-power GaN HEMT devices with internal input matching for base station applica-tions are described. For a three-way Doherty implementation using three 2x180-W GaN HEMT transistors, a an exceptionally high output power of 59.5 dBm corresponding to 1.5-dB gain compression point with a peak efficiency of 76%, drain efficiency of greater than 50% at around 7.5-dB power backoff and a linear power gain of about 12 dB were achieved across 1.8-2.2 GHz. By using a high-power broadband inverted Doherty amplifier architecture with a 2x120-W GaN HEMT transistor, a saturated power of greater than 54 dBm, a linear power gain of greater than 13 dB and a drain efficiency of greater than 50% at 7-dB power backoff in a frequency bandwidth of 1.8-2.7 GHz were obtained