300 W GaN power amplifier for LTE applications

This paper presents a 300 W GaN power amplifier operating in the LTE band 7 (2.62~2.69 GHz). From the loadpull simulation, optimum impedances of the GaN HEMT at the fundamental frequency and the second harmonic frequency are extracted for a maximum output power. The matching circuits that give the nearly optimum second harmonic impedances are implemented on a titanate substrate with a high dielectric constant and are integrated with a bare GaN transistor in a ceramic package. The fabricated power amplifier shows a saturated output power of 258~324 W and a drain efficiency of 67~73 % under the pulsed condition of 1 msec period and 10 % duty cycle. It also has an output power of 80~85 W and a drain efficiency of 42~49 % at ACLR of 30 dBc with the LTE input signal.